HOME HOMESTEADING LIBRARY CATALOGUE GO TO NEXT CHAPTER
CHAPTER FOUR
How will it be built?
30. How to think
The subject of this book is how to get a good house for little money, but no pound of ink and paper can do more than suggest paths for your own thinking to follow.
Let's pretend that you are four years old, therefore not as yet possessed by a set of store-bought answers. At this age and in this frame of mind every one of your questions begins with "Why?" Why brings a "because" response. Somewhere between Why and Because you can learn How to build a house.
I believe this process is called thinking. Thinking is more readily observed when it is absent than when it is present. You can recall hundreds of examples of not-thinking, most of them committed by yourself, some by others. We are talking about houses, and when we talk about houses, not-thinking gets expensive.
Sticking to houses, let's take one sample of not-thinking. The following is not a made-up horror story; it is true. I watched these houses being built, a whole row of them. Once upon a time there was a beautiful, steep, grassy hill.
On the next page I have sketched what was done. The hill faces south, too. This is excellent siting, provided the house is planned to take advantage of the hill, not struggle against it. Provided at the very least that the builder spends ten minutes thinking before he begins to dig. Here he has taken a house intended for flat land and put it where it obviously does not belong. Whether we approve of the house itself is beside the point. The point is that not only has the builder wasted opportunity, he has also wasted money.
Think how much work went into carving up the hill before the basement forms could be set. Think how hard it was to get the concrete up there to build the earth-retaining walls, two-thirds of which had no earth to retain.
Think how every piece of material had to be manhandled up the hill. Think how precariously the bulldozer teetered as it shoved that fill against the basement wall, which, poor thing, couldn't become a proper basement until it had some dirt outside it. Think with sorrow of the front door, located inaccessibly on the road side, because that's where front doors are supposed to be.
Think with regret that someone, having been told that front doors must face the road, failed to think about placing the entrance in the more readily accessible lower floor. Think with sorrow of the many windows which could have looked upon a beautiful view.
Think with anger that the laboriously placed fill, covering as it does the wall where the windows and doors should have been, now becomes an almost impossible maintenance problem. Think with nostalgia that the original heavy sod, which could have held a steep bank, is gone, lost in the digging.
Think to the future, when most of the fill will have washed down to be scraped off the road below, leaving the owner his choice of making an enormous rock garden, or remodeling the front of his house to a semblance of what it should have been in the first place.
If there is any humor in this situation, it is of the laugh-clown-laugh variety. The bitter humor stems from the attempt to force a given house plan, any plan, bad or good, upon an unsuitable site. In this particular case, the builder can not even say that he was following tradition. Ironically, there happen to be, right in the same neighborhood, some splendidly executed side-hill houses, built two hundred years ago.
Thinking is a subtle process, hard to teach, hard to learn. Not-thinking is easy. We are surrounded by things and influences that help us not-think. The best I can do here is to remind you of the more common causes of not-thinking. In housebuilding, the first of these deterrents to thought is--
TRADITION. To shelter himself for the night, a hunter builds his
windbreak like this:
Thus in the New England colonies the early housebuilders were experienced in turning their roofs to the prevailing wind and rain. The Indians were threatening, with the settlers carrying an axe in one hand and a rifle in the other. The winters were cold. Many of the builders did this:
Here we have the hunter's shelter, raised off the ground to make a place for the children to sleep. The house was oriented to present as little of itself as possible on the windy side, as much as possible on the sunny side.
Someone thought the house looked like a salt-box, and an architectural style had been named. It became a tradition. As soon as this happened, people began building saltboxes all over the place, oriented east, west, and north, as well as southeast. The copying builders never asked themselves Why. The original builder, grinning and minding his own business, never troubled to explain to his neighbors that he had a good reason for placing the long slope of his roof to the northwest. The reason was forgotten. The shape had become a tradition.
Any architectural tradition can be traced by someone to its original reason, which was always good, or at least seemed good at the time. Subsequent copying of the tradition, in the absence of, or in the perversion of, the original reason, is likely to be unjustified.
I have not said that tradition is bad. If the tradition fits your problem it is probably better, safer, and cheaper to follow it than to spurn it. The danger of a tradition is that you will follow it without thinking, which means, without asking why.
CUSTOM. There are tremendous pressures upon you to do what your
neighbor has done. For instance, the mortgage man at your bank
will be much easier in his mind if your intention is to build
a house exactly like the house next door, one which has already
been bought and paid for. The mortgage man not-thinks that the
second identical house will be worth the same amount.
Custom assails us from the outside. It gets written into law, into zoning rules, into building codes. It controls the not-thinking of government bureaus; it writes the rule books for financing agencies.
What is worse, it assails us from the inside. A lady said to me that she was "all through with this second floor nonsense. I'm too old to walk upstairs to make the beds." When I asked her why her house plans included a basement, she said, "Where else would I put the laundry? Every woman I know has her laundry in the basement."
The home craftsman put his first power saw in the basement because the basement was there, not fit for much of anything else. This is a temporary expedient. Custom then converts an expedient into habit, establishing the notion that you need a basement to make a place for your power tools.
The trouble with custom is that it makes you pay for so many things you neither want nor need. Custom sows and mows front lawns that never get walked on, and front doors that never get opened. Custom creates fences that keep nothing in or out, and gardenless garden walks that lead to nowhere. Custom puts fireplaces in the homes of people who don't want fireplaces, then faces them with brick because everybody knows that fireplaces are made of brick. Custom puts non-structural plaster on the wall because everyone knows that a wall has to be plastered. With magnificent non-thinking, custom puts the washing machine in the basement, the bed upstairs, thus locating the clean sheets two stories away from where they are going to be used.
As with tradition, I do not say that custom itself is wrong. Custom misapplied is wrong. Custom misapplied is the most skillful pickpocket I ever met. To keep your pocket from being emptied, try asking yourself, "Do I want this because I really want it, or because it is customary?"
MAJORITY. Ten thousand people, all believing one thing, can be
wrong, and one person who disagrees with them can be right. We
all know this in our minds, though perhaps not in our hearts.
We all can remember moments in history where one man was right
and all the rest of the world was wrong. The standard treatment
was to be burnt at the stake for being in disagreement with the
misinformed majority.
Some parts of the world have given up burning at the stake, but most of us cling to the notion that "the majority is right."
Nobody that I know of ever meant to say that the majority is right. All we say is, in the science of government, "the majority shall govern." This is a political idea to which I subscribe. But when this political process is unconsciously carried over into either fact or beauty, I object.
Neither the reason for, nor the beauty of, a rainbow can be determined by majority vote. No one calls a meeting to determine the product of two times two, and how many petals you like to see on a rose is admittedly your own business. By the same token, I submit that although thirty families on your street have voted to have basement garages, it still doesn't have to be a good idea.
ADVICE. The advice-shopper is a lineal descendant of the man who
believes in determination of fact by majority vote. The advice-shopper
believes that if he can get enough people to give an opinion,
he can add them all, divide by the number of advisers, and derive
the right answer.
The real dyed-in-the-wool advice-asker never worries about whether the people he asks are qualified to advise on the subject. Since the advice-asker has no opinions of his own worth mentioning, he feels that a hundred opinions, stirred well, are somehow better than ten minutes of solid thought in his own behalf.
Ask a hundred people whether to paint your house blue or yellow. Statistically, you will wind up painting it green. My advice to the advice-asker is, ask one good architect, and leave your friends alone.
AESTHETICS vs. STYLE. I defend the right of any man to decide
for himself what is beautiful, so long as he decides it for himself.
When you are making up your mind what you consider beautiful,
you are dealing with the philosophy of aesthetics. If you start
peeking around to see what the neighbors are building, you are
worrying about style.
You are entitled to change your mind about what you think is beautiful, but the chances are you will never change, or very slowly change, your approach to beauty. Style is a fickle thing; a monstrous mindless dragon in pursuit of the breeze-driven smoke from his own nostrils. We know for sure only three things about style: that it is never reasonable or thoughtful; that it is as quick as a kitten and ferocious as a tiger; and that it inevitably costs us money.
TECHNOLOGY. Domestic construction is the biggest single business
in the world, and most of it runs about sixty years out of date.
Tradition, custom, majority opinion, and friendly advice, used
as substitutes for thinking, introduce this two-generation lag
between what can be done and what is done. They are not reasonable
guides toward getting a good house for little money.
Considering the technology they possessed, many of our forbears did a wonderful job of building. It is technology that has changed, not people. We've grown a few inches taller in the past six generations, because of vitamins and stuff, but we still eat, sleep, work, play, make love, and put on our pants one leg at a time. A well-designed, livable, thoughtfully sited house of two hundred years ago is well-sited, well-designed, and livable today.
Power machinery which provides heat, light, and water at the turn of a switch, gives us more opportunities than our ancestors had to achieve comfort and freedom of design. Power tools and factory-fabricated building materials give us the opportunity to build with more economy than our ancestors enjoyed. In both sentences I said "opportunity." The power machinery, tools, and power-created materials still won't do our thinking for us.
The trouble with technology is there's too much of it. Building was more laborious but simpler in the days when all we had was clay and rocks and trees and an axe and lots of elbow grease. If the builder made mistakes, at least they were his own. Nowadays, with the accent on buy, buy, buy whether you need it or not, a team of consulting engineers is needed to figure out whether any one manufactured product is what we want to use or is even fit to use.
Technology without judgment can go wrong as fast as it can go right. Technology can build a skyscraper two thousand feet high with less trouble than it takes to offer a valid reason for doing so.
Let us float back to earth for a more homely example. Technology is now able to improve the tenacity of the mortar which holds one brick to another. This development excited the science editor of a leading literary magazine. He explained that the new mortar now made possible a prefabricated brick wall. All you have to do is lay up the bricks in the conventional manner, encase the wall section in a steel frame, ship the massive result to a building site, call up a towering crane, and presto, you can have a brick wall sitting eight stories in the air.
The science editor missed two points. First, brick is and always has been a marginal building material whose only virtue is that it can be laid up quickly on the spot. A prefabricated brick wall makes about as much sense as prearranged dominoes.
Second, the strength/weight ratio of brick is exceeded by scores of other building materials, some new in technology and some old, so that the notion of hoisting a prefabricated brick wall eight stories up makes me wonder if the technologists have not lost sight of the all-important word, Why,
HOW TO READ ADVERTISING. When my father, a country newspaperman,
ran advertising, it generally said, "John E. Smith Lumber
Co. Sells Lumber," or "Gilchrist Has Groceries."
These are transitive statements. As advertisements become more
competitive, they tend to become increasingly intransitive.
When the sign reads "Meadowdale Farm, Corn, Beans, Tomatoes," it presents a statement of fact which allows me to buy corn if I want corn. If the sign says "better corn," or "larger corn," or "cheaper corn," my inclination is to drive on and look for a less intransitive advertiser. Some day the sign will read "low-calorie corn," and then I will drive by happily, having at last seen everything.
Yet there is much to be learned from the transitive residuum in advertising. We can't say that all advertising is vicious and must be ignored. Let's learn how to read the stuff.
Remember that the advertiser has one goal and one goal only: to persuade you to buy his product. This is a simple and completely obvious fact. Everybody knows it, and almost everybody forgets it. Successful advertisements are those which do the best job of making the reader forget the advertiser's self-interest.
When you set out to build a house, you are going to read a lot of advertising, buy a lot of things, spend a lot of money. You will be assailed by advertising that wants to sell you "style," except that it is always called "beauty." You will be told that technical things, machines and materials, are better because they are "new." You will sink in a quicksand of hung comparatives--larger, smaller, lighter, softer, cheaper, better, and more beautiful. You will learn to ask, "Larger, smaller, lighter, softer, cheaper, better and more beautiful--than what?" If you still haven't gone blind you will observe that most of these bought and paid for comparatives prove nothing except that they are in direct contradiction of each other.
This kind of verbiage you can discount easily. Much harder is to discover what isn't there at all. In the welter of claims and counterclaims between competing products, there is no money anywhere for advertising aimed at persuading you to buy nothing at all. For example, you never saw an advertisement telling you not to paint your house, and you never will. Nobody makes a nickel out of not-painting. Furthermore, if I wrote an article explaining why your house doesn't need paint, no magazine that carries paint advertising could possibly print it.
Here are a few tips on how to read advertising:
Most advertisers make their loudest claim about what is actually their product's weakest point. That is, if the product is too small, the advertising will call it "roomy," hoping you won't notice. If the product is really roomy, the fact is self-evident and need not be advertised.
In your reading, strike out all hung comparatives. Delete smoother, finer, safer, and easier. Read only the statements of purported fact which are left, if any, after these deletions.
Strike out such ersatz phrases as Autosyntronic and Magicentrometer used to describe new miracle methods of keeping the washing machine running.
Strike out all aesthetic judgments. "Beautiful" is an expression of the advertiser's hope, not necessarily your opinion.
If the advertiser asserts plainly that his product is good, useful, and expensive but worth the money--and it may well be--read to find out why, skipping most of the adjectives, and skipping assertions that the product is either "new" or "easy to use." If the product is really good--the wonderful thing is that so many of our products are good--a declarative statement of its merits should suffice, and no "free gift" should be required to persuade you to buy it.
THE MISNOMER. A lineal ancestor of the advertising man is the
misnomer artist. To some degree we all possess the human penchant
for calling things what they are not, for calling that thing dangling
at our side a "limb" or "upper extremity,"
but never an "arm." The misnomer artist sees a piece
of treeless flatland and automatically names it Willowdale Heights,
thus escaping from reality in three directions.
The misnomer man decides that a rock well should be called "artesian," because few people can call him a liar and because the three easy syllables sit nicely on the tongue. He is the chap who decides that hens have quit laying small eggs, confining their efforts to super jumbo, jumbo, extra large, large, and medium. Women, he says, have quit wearing clothes, with garments being made now only for juniors and misses.
In the case of my favorite building material, wood, the misnomer artist has a field day. When we want to specify mahogany, we have to say "Honduras mahogany," because every other tropical hardwood gets called mahogany no matter what its name or attributes may be. "Maple," in the hands of the misnomer artist is neither maple nor maple colored nor solid anything, as opposed to "solid maple," which, although still neither maple nor maple colored, may with luck be partly solid, and still isn't "blond maple," which might be almost anything.
In fact, I can't think of a single named color bearing any resemblance to the natural color of the wood it is supposed to represent. Though a slow learner, I finally did figure out what "fruit-wood" meant, only to be paralyzed by the appearance of the real baffler, "distressed fruitwood."
When it comes to architectural styles, the misnomer artist goes completely out of his mind. Or perhaps I should say, we are driven out of ours. For examples, see any page of real-estate advertising. Here, I'll mention one out of dozens. After years of watchful study, I learned that a ranch house had one floor and a colonial house had two. Now I'm back where I started because they've begun to advertise the "one-story colonial."
At the end of the How to Think section, I'm depressed. The roadblocks
in the way of clear thinking about houses are awesome. There are
tradition and custom to confuse us, the myth of majority opinion,
too much advice and much too much mumbo-jumbo about style. There
are machines that may or may not be worth the money, and advertising
that must always be suspect because it originates in self-interest.
In a business as vast and complex as housebuilding, it is sad that there are many intelligent, sincere and honest people who are just plain misinformed.
Well, depressed or not, the rest of this section will be an old college try at how to understand, select, and build. Misinformed or not, if we keep asking why, we'll make out.
31. How to understand materials
Start to break a stick across your knee. Stop just after it pops and before you have pulled it apart. The broken ends will now look something like this:
Back up and do it again, this time looking at the bent stick just before it breaks.
The forces pulling apart are called "tension." The forces pushing together are called "compression."
The stick which you broke is a "beam." It represents, among other things, the floor of a house. Turning the sketches upside down, the side on which the grand piano sits is-called the compression side, with the other side being the tension side.
You are now one-quarter of the way toward being a structural engineer.
To proceed with the next quarter, get, or imagine, three more
sticks:
Take the little stick, a half inch thick by a foot long, and break it over your knee. That was easy. Now take the stick which is an inch thick and a foot long, and try to break it. Unless you are a professional strong man, you can't do it.
The difference between the two sticks is their "strength." You can take my word for it that, for the same material, the one-inch stick is exactly four times as strong as the half-inch stick. This holds true no matter what the two sticks are made of, whether it be pine, oak, aluminum, or steel. Strength depends on the square of the thickness.
Next, take the one-inch stick, four feet long, and break it over your knee. That also was easy. In fact, it took exactly the same pull to break the one-inch, four-foot stick as to break the half-inch, one-foot stick.
Since the stick represents the floor of your house, we are now talking about "span." We have learned that the one-inch stick is four times as strong as the half-inch stick, yet the effort required to break them is the same, because the one-inch stick is four times as long. Now we know that the ability to carry a load falls off in a straight line as the span increases, but comes up as the square of the thickness.
You are now one-half of the way toward being a structural engineer.
To go the third quarter of the way we need to do some measuring.
(You can either do the measuring yourself, or take my word for
the results.) It would be well to have a vise and a ruler, but
once again we start out with the same three sticks. This time
we will bend them, not break them.
Here is a rough picture of what we are up to:
Using the same push on the two short sticks, you will find that the half-inch stick bends (or "deflects") eight times as far as the one-inch stick. Yet we already know that the one-inch stick is only four times as strong.
Here we have observed the difference between "strength" and "stiffness." The one-inch stick is eight times as stiff, because stiffness depends, not on the square, but on the cube of the thickness.
Next, and this gets to be more and more fun, try the same load on the two one-inch sticks, one foot long and four feet long respectively. You won't even be able to measure the bend in the one-foot stick, but I can tell you that the bend in the long stick is a whopping sixty-four times as great.
The amount of bending depends on the cube of the length, and four times four times four is sixty-four.
Last, to check it all out, put the same load on the one-inch, four-foot stick and on the half-inch, one-foot stick. By now you know that the big stick, which is exactly as "strong" as the little stick, will bend eight times as far, and is thus only one-eighth as "stiff."
Applying all this to materials, we have learned from our three
sticks that any given material, made twice as thick, will be equally
strong over four times as much span, but will be equally stiff
over only twice as much span.
Good carpenters know these things, at least in sense if not in numbers, because they have broken sticks and felt materials bend beneath them. A fair question now would be, why do we care?
We care, for one reason, because a floor needs not only to be strong enough to hold us up, but stiff enough to be free of annoying bounce. A roof, on the other hand, needs be strong enough to hold up itself and the snow, but no one cares whether it is stiff or not. In planning for a roof and for a floor, two different sets of criteria apply.
You, along with all good carpenters, are now three-quarters of
a structural engineer, because you have at least a qualitative
understanding of the difference between strength and stiffness.
The last quarter includes information which might . be called
"characteristics of materials." Following are some of
the more important words to think with.
ELASTICITY vs. BRITTLENESS. Elasticity means the ability of a
material to bend or stretch, then return to its original shape.
Every elastic material can be described in terms of the force
required to bend it a certain amount, and every elastic material
has a point beyond which it will no longer return to its original
shape.
Squeeze a tin can a little bit and watch it go out of round, then return to where it was. Squeeze harder, and you will leave a dent. You went past the "elastic limit." Stiffness is not the opposite of elasticity, it is a measure of the force required.
In building, we like stiff materials, but all that means is we want the force required to bend the material to be high. Generally we want the elastic limit to be as high as possible, for beyond that point the material deforms permanently, and still farther beyond that, it breaks.
Much the opposite of an elastic material is a "brittle" material, which stubbornly refuses to change its shape, and then all of a sudden, under increased load or shock, comes apart.
This concept is important to us in the selection of building materials. For example, wood and steel have excellent elastic properties. Bows and springs are made of wood and steel, and will return to their original shape after bending thousands or millions of times. Plaster and cast iron are brittle materials. The first will break at a light tap, the second at a very heavy one. A brick or a stone will fall right in two, if you tap it at the right place. Let the foundations of our house shift but a little bit, and all plastered surfaces therein may crack, because plaster, though not strong, is stubbornly inelastic.
To erect a structure, we must use "structural" materials. The good ones possess both stiffness and elasticity. We then sometimes coat our structure with materials which have no stiffness at all. Roll roofing, for example, when warm, will assume the shape of anything it happens to be lying on. On a warm day, this is a non-elastic material. Unroll it, and there it stays. On a cold day, it is a brittle material. You can't unroll the stuff at all without cracking it.
CONDUCTIVITY. This characteristic, though not important to pure
structure, does concern you in the choice of materials for your
house. Materials with low conductivity help insulate the place.
Here we run into an embarrassing difficulty. Most materials which
make relatively good structure make relatively poor insulation.
Though some materials have lower conductivity than others of equal stiffness, the best and cheapest insulation of all is air, in tiny pockets or thin layers. The problem is to find or devise a material which embodies these air pockets without loss of stiffness. In a single, homogeneous material the problem can not be solved; it can only be compromised.
Advertising which says that a single material is good for both structure and insulation has to be re-read to say that it isn't too much good for either.
For building convenience, however, a product can be manufactured which we may describe as having a stiff surface on both sides, and a spongy interior. Remembering lesson one in our structural engineer's course, we see in this assembled material stiff skins on the tension side and the compression side, with the filling of the sandwich providing some insulation.
Having bowed toward the product designer, let's stick to fundamentals. At this stage of the game, let's keep on talking about stiff materials for structure, and special-purpose materials for insulation.
INSULATIVE MATERIALS. Another embarrassing difficulty presents
itself, because conductivity is far from being the whole story.
Heat flows into your house, or out, in three ways. First, though least important, with the air entering and leaving the house. This is called convection. It is not a problem of faulty materials. If your house didn't leak air, you would have to make it leak on purpose, because you have to have a certain amount of air to stay alive.
The second and larger heat flow is by conduction. Warm air sits against the ceiling, and the snow on the roof melts. It melts quickly or slowly depending on the conductivity rate of the roof structure.
The third and greatest heat flow is by radiation, which is the way all the heat from the sun got here in the first place. On a cold night the process reverses itself and the whole house becomes a stove, warming up everything within line of sight.
Here is the difficulty. The materials which reduce conduction and the materials which reduce radiation are not the same. Radiation, the worst enemy, is defeated by shiny, light-colored materials which are both good at reflecting the heat back where it came from and poor at re-radiating it on the other side. Conduction is defeated by porous materials which trap air.
In the pure sense, anti-radiation and anti-conduction materials are totally unlike each other. Neither kind is generally acceptable for either the inside or the outside surfaces of your house. Therefore we have to enclose them between more serviceable materials.
As a possible solution, we can have another manufactured product which encloses a porous material between two shiny surfaces. This is almost a dead stop both to conduction and to radiation--but it creates other problems, as will be seen later. The best compromise or money-saving solution I can think of is to omit the porous material and simply trap air between two or three shiny surfaces. They make "thermos" bottles this way, and the same technique will also give you a very comfortable house.
FIRE-RESISTANT MATERIALS. Anyone who has tried to set fire to
a pile of brush knows that his fire, to keep going, has to have
three things: air, warmth, and fuel. To make the fire burn faster,
you push it together; to put the fire out, you pull it apart.
This amounts to adding or subtracting fuel, as well as controlling
the amount of warmth versus ventilation.
You can put the fire out by pouring water on it, and thus cooling the fuel. You blow (add air) on the fire to get it going, but if you blow too hard too soon the fire goes out (it got too cool). Throw a wool blanket (or a foam blanket) over a fire and it goes out at once, having run out of air. Heavy, cool fuel added too quickly to a fire will put the whole thing out, because the temperature drops.
We were trying to burn the brush pile. By reversing the processes we can learn how to reduce the danger of house fires. The best way to keep a house from burning quickly is to make it long and low. A tall house burns as a torch burns, in its own draft; a low one behaves like a spread-out brush fire that keeps wanting to go out.
No material is "fireproof," provided the fire is hot enough. A masonry wall, itself fire-resistant, will help keep an outside fire from coming in, but it will heat up like an oven and increase the intensity of a fire burning on the inside. Masonry has a high rate of conductivity. The best materials for slowing down a fire are those which either reflect heat, keeping the rest of the structure behind them cool, or absorb heat slowly because their heat conductivity is low.
Insulation and fire resistance work together. Reflecting materials keep heat from getting into the supporting structure. You can check this for yourself with a piece of aluminum foil and two logs in the fireplace. Non-conducting materials take longer to reach the combustion point. It will probably surprise you to be told that post-and-beam structure, made of slow-conducting wood, will be standing long after a steel beam has reached its yield point and collapsed.
I have watched new/old buildings burn. The old part, built of heavy wood, remained standing; the new part, made of steel (even when encased in concrete) collapsed into a bonfire. The explanation is simple. The steel beam, which itself will not burn, loses its strength at around twelve hundred degrees Fahrenheit, or just a little more than the temperature of the match which lights your cigarette. It gets hot quickly, loses its strength, and dumps its load into the bonfire below. The wood beam begins to char on the outside at about the same temperature, but the inside remains cool for a considerable time.
We are plodding along toward the details of putting your house together. Characteristics of materials, weight, durability, cost, workability, appearance, fire resistance, cleanability, all have a direct bearing on how you will build your house.
In the next section we will look at the kinds of materials which are available.
32. How to select materials
We now share a vocabulary to use in discussing materials. We can communicate with each other on tension, compression, strength, stiffness, elasticity and brittleness, reflectivity and conductivity.
The next step is to make a rough grouping of the more conventional building materials:
WOODY MATERIALS. If we were forced at this writing to discard all domestic building materials except one, we would keep wood. Given nothing but a pile of boards, there is very little that a good carpenter couldn't build if he had to. The tree-lover would say this is because nature, in designing a tree, achieved strength, permanence, and adaptability. The physical chemist might say that wood is workably soft yet flexible because it is made of long lignin fibre embedded in cellulose. The builder might say that wood is tenacious. It is easy to bend but hard to break. When a wooden building falls down, it falls down slowly.
Wood doesn't do any one thing quite as well or as cheaply as some other combination of materials which might be found, but it does many things well enough. It is the basic building material, as far as houses are concerned, to which we add a variety of other materials in order to take advantage of their special properties.
A sawed board, plank, or timber is reasonably strong for its weight. It must, however, be used with some intelligence, because its strength in tension appears only along, not across, the tree's growth rings. A board is easy to work, with inexpensive tools, and easy to fasten to another board. Its heat conductivity rate is low. It is elastic, a wooden structure being tolerant of natural assault, even the shifting of its own foundations. Wood has a pleasant texture, not bad acoustic properties, and to most eyes a pleasing appearance.
Wood supply is a tremendous industry. There are many varieties of trees, for which the claims, counterclaims, and misnomers are bewildering. In this confusion there is a common misapprehension. "Softwood" and "hardwood" are botanical terms, not physical descriptions.
Softwood is from evergreen trees. Some softwoods are very hard. Some hardwoods are relatively soft. There is a widespread though erroneous notion, based probably on the sound of the words, that for a wood to be hard is somehow better than for it to be soft. If anything, the reverse is true. It is the very fact of tractability combined with strength that commends wood to us as a building material.
Most woods used for structure are softwoods. Many, though not all, softwoods are easy to assemble, accept and hold nails well, and have some natural tolerance to weather. Insofar as wood is actually soft, it is light in weight and easy to work. Going back to our structural engineering vocabulary, it is less stiff per unit of thickness, but since stiffness increases with the cube of thickness, most softwoods figure out to be stiffer than hardwoods per pound of material.
Translating that into carpenter language, if you want a given stiffness, use softwood but use a bigger piece.
The wood from each kind of tree has characteristics of its own, some good, some not so good. To describe them is easily another book. I can't do it here. I will conclude with the general injunction to use nothing but softwoods for structure and for outdoors. You can use hardwoods, if you feel like it, inside the house.
Manufactured wood products take on even greater variety. Plywood, used in astronomical amounts, is three or more thin layers of wood glued together, with the grain lying alternately crosswise. This partially gets around the fact that raw wood is much stronger, in tension, along the grain than across it. It also partially gets around the fact that wood changes its across-the-grain dimension as the moisture content of the air changes.
The statement is often made that plywood is stronger than raw wood. This is not true. Plywood represents a compromise strength, nearly uniform in all directions, and can be used with less thoughtfulness on the part of the carpenter. It has less stiffness than raw wood per pound or per dollar, but properly used it saves on labor. It is less tolerant to weather and to mechanical damage.
Wood is also cut into chips, then bonded together in the shape of boards or sheet. The strength of this product now depends on the strength of the bonding agent. Both chipboard and plywood retain much of the essential character of wood, while lowering its quality of tensile strength along the grain.
Wood chip is made into paper products which are almost indispensable to the wall and roof skins of your house. Even when, a little later, we recommend aluminum foil, we will mean a thin layer of aluminum laid on a paper base. Be warned right here, however, that one paper product is not to be used--tar paper. Tar paper does everything wrong. It attracts heat when you don't want the heat, gets rid of it when you do. It feeds and spreads fire. It welcomes insects and retains water condensation. The direct replacement for tar paper, paper-backed aluminum foil, does everything right.
To conclude, it is very hard to build a house which meets all of your specifications, including charm and economy, without wood.
MASONRY. There are many kinds of masonry. The oldest existing
works of man are fitted stone, laid without mortar. There is shaped
stone, laid with mortar. There is fieldstone (unshaped), laid
with mud or mortar.
A lot of building has been done with mud. There is dried mud, rammed mud, and baked mud. Bricks are baked clay mud, laid with mortar. With the invention of cement, which is ground and fired stone, came blocks, made of cement with various aggregates, put together in the same way.
I will call this whole group of materials the "assembled" masonries.
The monolithic, or cast, masonries are different. The invention of cement made it possible to cast structures more or less in one piece. This is called concrete, meaning a structure put together by the cohesion of separate particles. Assembled masonry uses large (brick-sized) particles. Concrete uses microscopic particles. I choose to list concrete as masonry, ignoring the size of the particle, because its strength depends on particle cohesion. Thus it belongs in the same family when virtues and faults are being considered.
The great difficulty with assembled masonry is its almost complete lack of tensile strength. It can stand lots of push, but almost no pull. With concrete this fault can to some extent be corrected by including steel reinforcing on the tension side. Concrete used in structures thus becomes a composite material, with one thing being used to correct the deficiencies of something else.
I also have to include plaster among the masonries. Plaster is masonry laid on with a trowel. My personal definition of plaster is "a disguise to cover deficiencies in earlier workmanship." Plaster, to me, is not a structural material at all. It has no tensile strength, little compressive strength, and no elasticity to speak of. In my opinion it is also heavy, dirty, troublesome and expensive.
In looking at the structural virtues of masonry in general, we soon see that they all have to be qualified. All masonry is heavy in terms of strength per unit weight. Most of it is expensive for what it accomplishes. Assembled masonry can be used only in compression, since it has no tensile strength. It has no elasticity and thus is not tolerant of shifting or shaking. Its heat conductivity is high, that is, for our purposes, poor, and masonries that are dark in color have, for all of our purposes except building fireplaces, undesirable radiation characteristics.
For a domestic structure, another big trouble with masonry is that it is hydroscopic. It absorbs water. Any other building material used to complete your house has to be protected in some manner from exterior masonry, which is always wet. This can of course be done, but it is expensive and troublesome. If you don't do it, you'll be sorry.
I admit that masonry in its place is useful and charming. My house sits on concrete footings. The fireplaces are made of cinder block, though lined with steel and ceramics. We have a variety of earth-retaining walls, some of concrete block and some of fieldstone, and the garden wall, laid of irregular granite discards, is undeniably beautiful.
They say that masonry walls are fire resistant, pointing to the fact that part of the brick wall remains standing after the house burns down. A brick wall is fire resistant all right, but it makes a fine oven to hurry the burning of the roof, which usually burns first anyway. I think I'd rather put my money into a fire-resistant roof. Another thing they tell me is that masonry is permanent. It is, until something comes along to start it falling down, in which case it falls down in a hurry.
Reinforced concrete has many more virtues than assembled masonry, but it has two faults--limited elasticity and a propensity to absorb water. My conclusion is that we should use masonry where its special virtues commend it to us, and nowhere else.
GLASS AND PLASTICS. Chemical manufacture creates products which
are essentially different in molecular form from the raw materials
used. In this sense, these materials are "synthetic."
The oldest of these is glass. In a structure the function of glass
is to let us see our environment, yet not be a part of it. No
other material does this anywhere near as well. It should be remembered
that the purpose of glass is to see through, and keep the wind
out. Beyond that, it has no structural virtues. The so-called
glass brick violates every rule for a structural material: it
has no reasonable purpose except that its texture can provide
an occasional design accent.
If you want something that will let light in but still not be transparent, many plastic materials do the job better than glass. Already the versatility of this new range of synthetic materials has become apparent. They offer translucence or opacity, permanence, ease of shaping, light weight, built-in color, textural range, and low maintenance cost. Now that plastics are available in elastic rather than brittle materials, it is hard to see how they can fail to achieve wide use in walls, floors, and roofs of domestic structures.
The development and application of synthetic materials is, as of this writing, the fastest growing use of technology. The prime mover behind all this is the rapid depletion of natural materials. We are now wrapped, sealed, and to some extent tooled with synthetics. Soon we will be surrounded by them.
Already the vinyl family of synthetics has demonstrated that it can meet the conflicting requirements placed upon floor covering. Other synthetic formulations will be developed to satisfy requirements for walls and roofs. Machines will be designed to produce these materials at a price competitive with natural materials. The time may not be far off when natural materials, in diminishing supply, will become exotic. They will be used only for unique mechanical properties and aesthetic virtues.
METALS. Steel, contrary to popular belief, is inherently the most
economical material of all. If you want the most building per
dollar, and you are not too concerned about aesthetic considerations,
the answer is to build with steel.
Steel is very strong, stiff, elastic, and--here comes a new word--isotropic. That means it has nearly the same strength and stiffness in all directions and thus can be used with less intelligence than a non-isotropic material. It can be manufactured in a vast variety of structural shapes, at little extra cost. These shapes are easy to put together. In theory, steel's major flaw is that it has to be protected from rust.
Although the all-steel factory has become almost an axiom, the all-steel house doesn't seem to catch on. It doesn't even catch on with me, and I know exactly why. Steel does not lend itself to my goal of revealed structure. In a bridge, yes, but not in my house, my personal haven.
For the steel house to become both actually and aesthetically warm, acoustically quiet, and in the domestic sense "pleasant," every bit of it has to be covered with something else. This involves "decoration," a costly process to which I object.
The next step, already being taken, is to combine steel with other materials in hybrid manufactured products which retain the virtues of steel (including, we hope, its economy), yet escape its excessive structural functionalism.
Aluminum is quite different. Light in weight, light in color, and rust-free, aluminum in some form or other has become an essential part of every house. By the pound, aluminum is expensive. Used in the right place, a few pounds go a long way. It reflects heat, stops air flow, controls condensation, discourages insects, and is fire resistant. It sheds no dust and it is easy to apply.
Aluminum is not an all-purpose material (for airplanes, yes, but not for houses), but the things it does well it does very well indeed. I buy aluminum foil by the dozen rolls, and use it everywhere. Whereas on many materials I have said, use with caution, aluminum foil is one of the "if in doubt, do" materials which can do no harm and may do a lot of good.
Having taken a fast look at the virtues of some basic materials,
in the next chapters let's go to work on how to use what materials
where.
33. How to build a footing
The ground beneath us is not necessarily stable. Its willingness to move around varies from point to point. Its ability to stay put depends on the load we put on it. The Washington Monument, they tell me, loads the ground beneath it at something around 18,000 pounds per square foot, and it is settling slowly, though uniformly. Pisa's leaning tower is an example of non-uniform settling. The ground under one side happened to be softer than under the other.
We have all seen sway-backed houses. Old houses, and some new ones too. The sway-back is usually caused by excessive ground loading. I worked on a house where the architect had specified an extremely massive chimney block at one end. Instead of leaving it hollow, as drawn, the builder chose to fill it with concrete. The ground loading in this case rose to about 10,000 pounds per square foot. The chimney block settled so fast, carrying the end of the house down with it, that the plaster cracked before it was dry.
With light ground loading, there should be no trouble. At a thousand pounds per square foot almost any ground, unless it's an outright swamp, will hold you up. In case this ground loading business bothers you, imagine a two-hundred-pound policeman, with flat feet and wearing number twelve shoes, walking softly across a patch of mud. His ground loading is not far from a thousand pounds per square foot. If he breaks into a run and begins to stamp his feet, the figure goes up to around three thousand.
The vertical footing, sitting on its narrow edge, creates excessive ground loading. Under multiple-story houses, loadings of five or six thousand pounds per square foot are common, or about twice as much as our policeman in a hurry. The fact that the vertical footing has been dug several feet into the ground serves only to increase the weight of the footing itself and thus makes the loading worse.
Six thousand pounds might be all right at one point, and not all right a few feet away. The easiest way to stay out of trouble is to keep all loadings low.
Here are profile views of various house footings. The first one, a full pad, has the lowest ground loading of all.
This footing floats the whole building on a concrete platter. In doubtful situations, perhaps involving deep loam or ground water close to the surface, the full pad is the best guarantee against irregular settling.
The full pad is also a bargain in that it provides a completed floor for shop and play areas, or for the whole house if you like it that way. My personal preference is to see the living area floor raised sixteen inches (two steps) above the pad. The resulting space can be used for pipes and wires, and if you choose as one big heating duct.
The first pad-builders buried all pipes and conduit in the concrete. I don't care for this technique. It violates flexibility, leaves nothing fixable or changeable. The early pad-builders made another mistake in omitting the plastic film moisture stop. This gave pads a bad name because they got wet and stayed wet. With the plastic film below, they still get wet from the air above, but not so badly.
In my opinion the full pad should be used only in cases where the ground loadability is doubtful. I don't think it is the best way to begin building most houses.
If you are sitting on good solid ground, there isn't much need for a continuous pad. Here is a view of a multiple pad footing.
The lower small-scale view shows a pad for each post. First scrape away the loam and save it for your garden. Make each post-supporting pad big enough to keep the ground loading to a thousand pounds, then put some smaller pads in the middle of the house so the floor joists can be small. For level ground, it's hard to imagine a cheaper footing, or one which disturbs the terrain any less.
Pad footings, either continuous or multiple, are your best bet for use on newly placed fill. But don't build anything on recent fill if you can avoid it. Undisturbed ground is likely to stay put. Disturbed ground tends to shift around before it settles down.
The wall footing needs to be talked about only because so many millions of them get built.
You will recognize this as one wall of the conventional basement. Let's take another look at history. The full basement, now an anachronism, used to be needed. Great-grandfather, having dug a hole in the ground, put a wall around it. He built his wall of rocks because that's all he had. With the wall sitting there, he used it as the footing for his house. Whether he knew it or not, he had done several things wrong, mainly because he had no choice.
First, because the masonry wall is heavy, and is vertical instead of horizontal, the ground loading is too high. Today, this can be corrected with a big sub-footing, but great-grandfather had no means of making one. Second, he had to build with assembled masonry, which has no tensile strength, therefore no power to resist local failure. His footing was liable to sag in spots. Third, he had to build an earth-retaining wall which was straight up and down, and thus was loaded from the outside only. A properly built earth-retaining wall should lean into its load. Fourth, ground water was free to come in and turn his basement into a pond.
Having turned up my nose at the full basement wall-footing, I admit that the single earth-retaining wall, as sketched, can be a good architectural device if used properly. It lets you set a shop or garage into a hillside and perhaps cut down on driveway steepness, or on stair climbing. If, however, this wall is to be used as a footing for additional structure, please make it of reinforced concrete, not assembled masonry.
How many square feet of footing do you need? I have already suggested that you hold the line at 1,000 pounds per square foot. Now you may ask, how much does a house weigh? That's the same as asking me how long is a piece of string, but I will do my best to give an answer.
For a minimum weight of house, contents, and extras, use 100 pounds per square foot of floor and roof area. A two-story, 2,000-square-foot house with 3,000 square feet of roof would, by this formula, have two times two plus three, or 7,000 feet of horizontal areas, adding up to 700,000 pounds of possible ground loading.
Anything can happen in a house, however, and for a safer formula use 150 pounds for the floor areas, staying at 100 for the roof. This comes to two times two times 150, plus three times 100, which gives us 900,000 pounds, or roughly a million.
Now let's assume that 2,000-square-foot house is 70 feet long and 30 feet wide. Around the outside it measures 200 feet. Divide a million by 200. The result is 5,000 pounds to the running foot. Add a thousand pounds for the weight of the footing alone and the answer shows that the load is too great.
I do not criticize grandfather's vertical footings. I do criticize builders who have imitated him without asking why he did what he did. Even after the basement is dispensed with, the notion persists that a footing has to be a vertical wall. Here is an example:
Imagine a house sitting on top and you can see how the ground loading has gone up. If you took the same piece of concrete and laid it out flat, you would have a far better footing.
Exactly at this point you may ask, "But what happened to the frost line?"
To answer your question, let's go back to grandfather. His house was heated only in the center, around the fireplace and the kitchen stove. A bucket of water close to an outside wall would freeze. Our houses now are vast though low-temperature ovens, even when we go south for a month and leave the thermostat at forty. Given a little insulation, such as a house sitting on it, the natural temperature of the ground below us is a uniform forty-five or better. The
ground beneath and immediately around a heated house simply does not freeze.
The footing which I suggest for your dream house, is the one which
in my experience has proved to be most reliable and least troublesome
to build, a set of posts. Even while the cries of amazement and
the screams or rage are rising, I continue to insist that this
to me is the most versatile footing of all. It can be used almost
anywhere. It probably goes far into pre-history as the foundation
of the first recognizable man-made dwelling. Architects have rediscovered
it time after time, and as of this writing, are discovering it
all again.
Here is a picture of the footing underneath the office where I sit at this moment. I dug some holes, throwing the top loam aside, and in the holes set heavy, chemically treated timbers. I filled the holes with clean gravel and tamped it down. No power machinery was required, just me and a shovel. Then I nailed the first set of floor beams right across the sides of the posts, and the building went up from there.
Having talked so much about ground loading, I should explain here that a post, called by the builders of docks and skyscrapers a "piling," picks up ground loading area from its sides as well as its foot. I'd rather not go into the reasons for this right now, but if you don't believe it, just try to pull a well-set post out of the ground.
Most builders will prefer cast-in-place concrete posts rather than wood timbers. If you do, don't forget to include steel reinforcing, plus bolts for holding down the floor timbers on which the house is built. Nevertheless, my sketch remains the same whether you use timbers or concrete.
The sketch shows the sun coming in on the long dimension of the building rather than cross-ways. The preferred location for a post-footed house is a south-facing hillside. On a winter day, the sun, coming in at a low angle, warms up the ground beneath. At night the ground tries to re-radiate heat in all directions, but finds little to cool toward except the house above it. Solar heat storage material, in this case the ground, has been provided for nothing.
Man's original intention in building himself a post-footed house may have been to keep away from prowling lions. Few of us are seriously troubled by lions today, but post footing does neatly help us to escape another natural enemy, ground water. Setting posts does not disturb the physical structure of the earth beneath. In most cases it requires no earth-moving machinery heavier than a shovel. It creates almost no disruption of environment. Nothing is moved which has to be taken away or put back. Best of all, there isn't any water in the basement.
In the scramble for living space, the post footing allows you to build your house wherever you like, at the lowest cost. It also gives you the greatest freedom to create a house which looks as if it belongs where it is. Of all possible footings, I like it best.
34. How to build a roof
In post-and-beam construction, as soon as the footing is in place, the roof goes up on its supporting posts. This is a very important advantage. Immediate shelter has been provided for both materials and workmen. Therefore the roof comes first, but we have not as yet designed it.
The first thing to decide about a roof is its slope, if any. Both the structure and the covering of the roof are determined in large part by its slope, or "pitch." This is spoken of as the number of inches of rise for each foot of horizontal travel. One inch of rise to the foot is "one pitch," six inches rise to the foot is six pitch. Naturally, twelve pitch is one foot to the foot, or forty-five degrees, while a flat roof is zero pitch.
The flat roof is wrong on all counts, the most important being that gravity doesn't help it shed water. The weather surface has to be much more carefully built to avoid leaks. It becomes at least twice as expensive per square foot as a sloping roof. Structurally, the flat roof is also more expensive. A sloping roof lends itself to the design of economical beams and trusses, such as you observed in the classic A-frame truss. A flat roof goes back to the uniform section beam of our somewhat more remote ancestors.
Roof pitch is an important dollar decision. There are three considerations to balance against each other: area; construction cost per unit of area; weather surface cost per unit of area.
As the pitch increases from zero, the area at first shows little increase. A one- or two-pitch roof is not noticeably larger than a flat roof, but it does allow water to run off. A twelve-pitch roof is almost one and a half times as big as a flat.
Construction cost goes down until about three pitch is reached, then begins to climb rapidly. This is based both on beam cost and on boarding area.
Weather surface cost comes out much the same. The steeper the pitch, the poorer the weather surface can be, because water runs off easily. A low pitch weather surface is fairly expensive for materials, although less costly for labor. At anything above four pitch, the unit area material cost remains the same, labor cost goes up rapidly because the carpenter can no longer stand on the roof, and of course the area increases. Remember that roofs cost more to build then walls.
The silliest fad I have seen lately are these ultra-steep roofs which come all the way to the ground. If they were intended to rear above the snow on a picturesque mountain top, I might get the point, but I couldn't design a structure which would give you less interior space for your money.
In any well-built house, the roof is the most important and most expensive part. The square-foot cost of roof coverage is largely determined by its pitch. I have already admitted there are valid considerations leading toward raising or lowering the pitch. Someone has to flip a nickel and decide. I've decided. For what you know to be my favorite roof, a single plane lifted toward the south, I prefer one pitch.
The first sketch shows one inch to the foot, on a single slope. The sketch at right shows a low-pitch version of the more conventional A-frame roof, to which you might be forced by location, building code, or just plain preference.
For the A-frame roof I prefer something around three pitch, as sketched. A relatively low pitch of this kind gives the effect and has all structural advantages of an A-frame, plus a pleasing interior, but doesn't waste much enclosed space.
Grandfather built his roofs like this:
The feet and inches are there to indicate pitch, not the actual dimensions of houses and barns. Grandfather seldom built with less than a six pitch, and his roofs were often steeper. They had to be steep for they were put together with assembled materials; shingles, slate, tile, or thatch.
All assembled roofing materials depend entirely on gravity to shed water. Take shingles, for instance. Wood shingles will shed water at six pitch, but not much lower. Imitation shingles made of tar paper can be used, at your peril, down to four pitch.
The more broken up the roofing material the steeper the roof has to be. It was thatch for the poor and slate for the not-so-poor that gave rise to the extremely steep roof lines of ancient villages. We find them picturesque. The dwellers found them expensive.
By the way, great-grandfather usually put an even steeper roof on his barn than on his house. He needed room in the haymow. He kept his hay upstairs so he could fork it down to the cows in a hurry at feeding time.
The steeper the roof the more expensive it gets. There is more frame to build and more area to cover. Above four pitch the carpenter can no longer walk around comfortably as he works, but requires something extra to stand on. The scaffolding costs money and the carpenter works more slowly--thus adding to the cost in two ways at once.
Out of necessity, great-grandad started another architectural detail. His steep roof, which had to be steep to be waterproof with a shingle skin, created a big V-shaped space which he couldn't afford to heat. So he built a ceiling. Sometimes he put a floor in the Vee and the space above became an attic.
Being there, the attic became a useful shelter. In pursuit of gracious living therein, grandfather cut holes in the roof, covered them with little sub-roofs, and Aunt Mary and the extra children had a place to sleep from which they could see out. It was expensive, but necessary. The dormer window had been invented.
Having been created out of necessity, steep roofs and dormers became a style, the right way to build a house.
Eventually this curious architectural form evolved.
The dormer window has grown until it almost, but not quite, engulfs the entire roof. The builder has gone to a low pitch on his dormer, to make more room inside, then has left a foot or so of token roof showing on each end, just to prove he knew what was "right" in the way of rooflines. You can see that having two roofs complicates the structure and costs a lot more money.
I drove down a street last night where these things stood row on row, all with full dormer roofs on both sides, all with a useless scratch of shingled roof on each side of the dormer, all with a token foot of roof above and below the dormer.
There were scores of them. Had each of the owners contributed the two thousand dollars of wasted dormer money in his house, the people on that street could have endowed an orphanage.
The roof is the most distinguishing feature in a house. It is
also the most expensive part--in first cost, in maintenance, and
in heat loss. It behooves us to think carefully about how to get
the most roof for your money.
Whether you are building a house, a factory, or an auditorium, you have a choice between a combination of structure and skin on the one hand, and the alternate combination of basic structure, sub-structure, and skin. Here is a picture of structure and skin:
I have broken away the roof boards to show the conventional rafters underneath, and to illustrate how the rafter supports, the skin encloses.
Here is the alternative--basic structure, substructure and skin.
The posts and beams, spaced far apart, constitute the basic structure. Sub-beams running the long way of the roof, spread the load and support the skin.
This three-unit structure, or beam, sub-beam and skin, is a very old principle, and mathematically sound. What will surprise you is that it is actually cheaper than the two-unit, or rafter and skin arrangement, because it takes fewer pounds of material to support a given load over a given span.
Not only is it cheaper, but it makes a handsome structure, nice to look at just as it is. Now that we have decided to reveal structure and dispense with cosmetic decoration on the interior, this is an important point. I wouldn't care to look at rafters all day every day myself, but the pattern of beam and sub-beam looks good.
I also point out that the board or panels on this roof run in the correct direction, with the slope rather than across it. The stiffness of the boards thus is added across the greater span, and the board immediately above each beam becomes a part of that beam and increases its effective depth.
As for the material of which your structure is to be made, I say quickly that in your most-for-the-money house you will use wood. Per unit of strength, wood is more expensive than steel, but it can be exposed to the eye without apology and without covering.
What kind of wood depends on what you regard as attractive. Some kinds of wood are stronger, size for size, than others, but that tells you only what size timbers to use, and how many. I have never been able to understand why some building codes specify kinds of wood. The important thing in revealed structure is that you think the wood looks good and feels good. Some of the structural woods do not. For example, fir, a wood required in many building codes, and hemlock, equally stiff, are splintery and not of pleasant texture. I recommend instead almost any member of the spruce or pine families.
What you will be seeing of this structure are the posts, beams, cross-beams, and the bottom side of the first layer of skin, which will probably be either boards or plywood. You and your architect can have fun deciding what combinations of texture and color you prefer. Remember that if you accept what I have been saying about useless and expensive decoration, you are not going to paint or even stain your overhead structure. The colors will stay light and handsome if you leave the wood alone. With the money you don't spend on cosmetics for your house you can buy a second car or build a bigger dwelling.
The roof skin has to keep heat from moving either way, by conduction or by radiation, and it has to keep the rain out. This task is complicated and expensive. Some compromise between total success and economy has to be made. Here is an exploded view, in profile, of the best roof I know, all things considered.
This may look complicated to you. It isn't. Let me explain how it works, and how easy it is to put together.
You know that it is much easier to work down than to work up. I mean gravity-down, not prestige-down. My wife rests the iron on top of the ironing board, not underneath. In my roof assembly the carpenter spends all of his time nailing down, not up.
It goes together like this:
I have found one variation on this scheme which doesn't greatly reduce its effectiveness and perhaps saves a little money. For layers 5 and 6 you can substitute a layer of the cheapest available insulating "board." I don't advise the substitution, but if you are pushing hard to save nickels, it will work.
I'd rather see you use the three layers of foil and get the benefit of the two layers of air. The second one reduces both conduction and radiation to as near zero as it's worth trying to get. The foil used here is not, of course, the kitchen variety. It is builders' foil, a sheet of aluminum on a backing of kraft paper. We use it shiny side up because we want drips and condensation to run off easily and cleanly.
At this point I have to answer a question from the floor. "What happened to the glass wool, rock wool, or mica flake that are often recommended as insulation?"
Answer: you may if you wish double the thickness of the spacers, remove the middle layer of foil, and fill the two-inch space with wool. You will get the same effect for about the same or a little more money.
I have three reasons for preferring multiple foil and air. The first concerns insects, who love to build their homes in the warmth and comfort of a wool batt, but are discouraged by the bleak horizons of aluminum. The second reason concerns fire resistance. If, by sad mischance, the lower layer of board burns away, the batt insulation will fall down of its own weight, exposing the upper layers to further damage. Foil will stay where it was put much longer.
To get at my third and most important reason we have to explore a whole new topic, dew.
Your weather forecaster talks about the "dew point." The ability of air to retain water vapor depends on its temperature. As air cools down, it reaches a temperature, depending on how much water vapor it had to begin with, where it has to get rid of some water. That is the dew point. Air, approaching its dew point temperature, then coming in contact with a cooler solid body, deposits its excess water thereon. This is dew, wetting not only your feet in the grass, but steel, wood, glass, masonry--in fact, everything at the critical temperature.
Dew doesn't "fall," it "forms." When dew is forming on the grass, it is also forming on the ignition system of your silent automobile. Worse, it is forming somewhere on or inside the walls and roof of your house.
In these three sketches, the dotted lines represent a graph of temperature, same time, same place, same day, or rather, same evening, but three different houses.
The sketch at left shows in simplified fashion an "uninsulated" house, with an inner skin and an outer skin and some air in between. With the outer air cooling down, and heat flowing more or less freely from inside to outside, the condensation line almost always occurs on the inside of the outside. From there, in pre-insulation construction, the water runs down and soaks into the sill which eventually rots away, but at least the outer boarding stays dry and the paint stays on. All of us have seen extreme cases where the dew forms on the outside of the outside, where it does no harm at all, but only warns us that the house is losing heat at a great rate.
No one builds houses like this any more. There is always some pretense at insulation. When, a few decades ago, insulation became fashionable, there was a great wave of filling the air space with some kind of woolly or flakey material.
The middle sketch shows you what happens with this kind of insulation. The temperature at which dew forms is now almost certainly to be found somewhere in the middle of this semi-solid mass of insulative material. The dew is deposited there, and it stays there. The whole wall or roof gets wet and stays wet. A few weeks later the outside paint--this type of house is always, but always, painted--begins to peel off. In extreme cases, given a little more time, the inside plaster--this type of house is always, but always, plastered--begins to fall off too.
The third sketch, at right, shows you what happens when we go back to the original scheme but add two layers of foil. The condensation line will almost always be at the outer foil layer. Since water and aluminum are not even country cousins, the dew forms not so much as moisture but as actual droplets, which run down and away freely. If by chance you ignore my advice (many do), and paint the outside and plaster the inside of your house, both paint and plaster will stay dry.
But why, you ask, doesn't the water which runs down rot the sill? Answer: later you will discover that it runs out to the ground. In the first place, your ideal house doesn't have a sill. Second, if it did, the wall wouldn't be on it at all, but outside it.
Walls crept into the roof section because both suffer from this dew point business. I can now state my major structural (though not aesthetic) objection to the flat roof. There isn't any way for the dew to run out.
Go back, please, to my roof profile sketch. As we have said, each layer of foil is actually a skin of aluminum bonded to heavy paper. Each layer has its shiny side up. Though I can't predict which layer is going to be the dew point, I don't care, because each layer eventually drains to the back of the roof.
Another question that may arise concerns the double coverage roofing. This is shown on the assumption that our roof pitch will be somewhere between one and three, and there we are back to pitch again as the important factor in many decisions.
A flat roof requires the so-called built-up roofing, which is multiple layers of paper and tar, covered with gravel. With no assist from gravity to remove water, the job must be carefully done to be leak-proof.
From one up to three pitch, double coverage is required. This type of roofing can either be stuck on entirely with tar, or nailed first where the nails don't show. Unless something punches a hole in the roof, there is little chance of a leak.
From four pitch up you can use single coverage roll roofing. Single coverage roofing is laid on with only a narrow lap, and the nails show. This roof will keep you dry for a while, and it costs only half as much as double coverage, but the chances are that to keep the roof free of leaks another layer will be needed before too many years. Here, by the way, is a chance to do some installment building if you're short of cash. Single coverage now, with double coverage right over it when you can afford it.
For six pitch and up, aluminum sheet roofing has some impressive advantages. It is fire resistant, heat reflective either way, and permanent. Because of the difference in thermal expansion between solid metal and the wood underneath it, the aluminum sheet may loosen its fastenings and leak. Use it with caution except on utility buildings where an occasional leak won't do any harm. If and when someone invents a way to lay leakless aluminum, I will cancel this last statement and go for it as the finest of all weather surfaces.
You will recall that I shrugged off shingles as a hopeless and expensive anachronism. If by chance you don't believe me, or your heart tells you that it isn't a house if it doesn't have shingles on it, remember that four pitch is the absolute bottom limit. Below that, shingles leak.
After all this talk, the roof that I recommend is exactly the
one shown in the sketch. That tells you about everything I know
on the difficult and important subject of how to build a roof.
35. How to build a floor
Now that we have a roof over us we can work in any kind of weather. The next step is to build a floor. It makes a level place to walk around without stumbling.
Again we start with structure. Floors have to be stronger than roofs. Short of a snow depth running to very many feet, the heaviest load ever put on your roof structure is two carpenters walking around driving nails. Two feet of snow, with some rain thrown in, weighs less than fifteen pounds to the square foot. I use thirty pounds per square foot, plus the weight of the roof itself, in figuring required roof strength.
As for the floor, I can imagine a party going on with one person for every 10 square feet. This averages the same fifteen pounds to the square foot. Now add a grand piano, play it, ask everybody to dance, and the figure goes up by somewhere between two and three. I use eighty pounds per square foot for figuring required floor strength.
However, and this is a big however, the determining factor in a house floor is not strength at all, but stiffness. We don't like the floor to dip and bounce beneath us. Stiffness, as you will recall from the second quarter of our structural engineer's course, falls off twice as fast as strength when span increases. To keep our floor structure light and therefore inexpensive, we want to support it at as many points as possible.
To illustrate: Let's say that a certain kind of four-by-eight timber is adequate for a sixteen-foot roof span. The same timber will prove barely adequate for an eight-foot floor span, the difference, very roughly, being at least two to one.
If the support is every four feet both ways, two-by-four timbers are good enough. The ultimate support being the ground, the decision as to the weight of our floor structure depends in every case on how far away the ground is and how often we want to reach down to it.
I'm almost afraid to mention rules of thumb, because every case can be different, but here goes. The hillside house, sitting on posts, is going to have a post every eight feet in both directions.
If the footing were instead a continuous pad on level ground, the shop and playrooms might use the slab itself as floor, with the rest of the house sitting on concrete blocks located every four feet. Like this:
Note the similarity between the floor structure as sketched, and the recommended roof structure of the preceding chapter. The three-way system of beam, sub-beam and skin gives you more for your money, no matter what the load or the span, than a two-way system of beam (called rafter in a roof and joist in a floor) and skin.
The bottom of the timbers actually in contact with the concrete blocks is chemically treated, and no untreated wood is ever in contact with masonry.
If still more space is required for some reason, or if you want your floor to be a little farther off the ground, you can go up on another layer of concrete blocks, or on stubby posts. Always raise in even increments of eight inches, that being the step height which the human leg prefers.
The skin (some would call it the floor, as distinct from the floor structure) carries the final load. Assuming for the moment that you are concerned only with load and not with insulation, how thick shall the skin be? First you must decide whether the skin will be one layer or two. To arrive at a good decision we have to talk history some more.
The conventional floor is built up in two layers, a sub-floor and a finish floor. The first reason for beginning with a sub-floor, strangely, is plaster. The plasterers grind their dirt into the sub-floor, then the finish flooring, when laid, covers it up. Eliminate plaster, as I hope we have agreed to do, and one layer of floor skin, of the right thickness, is enough.
A second reason for the sub-floor comes from the lumber industry. The so-called "one-inch" board has shrunk through the decades until the present industry standard is 25/32 inch. The same thing happened to the "two by four," which commercially is 1-5/8 by 3-9/16. The "inch" board today isn't even sawed an inch thick before planing.
Why is this important? Because, although the so-called "one-inch" board is about 3/5 inch or a little more than half as strong as a true one-inch board, it is less than half as stiff. This means that two commercial "one-inch" boards, placed on top of each other and having a total thickness of roughly 1-1/2 inches, will bend more under your weight than a single board that is truly one inch thick.
I build my own floors with the lumber industry's next weight of board, called "five quarter," sawed to 1-1/4 inches thick. I have it planed to 1-1/8 inches. It costs 60 per cent as much as the two commercial "one inch" boards which it replaces, and is roughly half again as stiff. Also the single board won't squeak, the squeak being produced by the two boards rubbing together as they bend.
At this point the carpenters are walking on a floor made of 1-1/4-inch
boards. The floor is stiff. Its durability cannot be improved
by the addition of any other material. If you want to, you can
run a floor sander over it and call it done. That is what I do.
However, a bare wood floor will try your patience for several
years while it converts dirt into patina. One coat of linseed
oil right after the sanding will make localized dirt less obvious
and speed up the patina process.
A floor does a lot of work. It is required to be soft to the foot, undeniable by the tilted chair, quiet under the impact of high heels, impervious to cigarette ashes, stable under the hasty step, and easy to clean. A softwood floor achieves the best compromise between these conflicting requirements, but you may not want to look at bare boards. You may believe that with a covering, the floor will be nicer to the eye or smoother to the mop.
Whatever your choice may be, I suggested earlier that your floor should be lightly textured in smoothness, so as to be hard to slip on but easy to sweep, and heavily textured in appearance, so as not to show dirt.
Before covering your structural floor at all, remember that serviceable floor coverings are expensive. They will probably cost more per square foot than all the rest of your floor structure put together. My suggestion is that you use your wood surface for a while and see how you like it. You won't hurt it a bit. You can always add the covering later, provided the original walk-on floor was stiff. Here I rest my case for thick boards, and move on to the insulated floor.
Your idealized hillside house will have air, not earth, beneath
it. This will save a lot of money on site preparation and footings,
but some of the profit must go back into a better floor.
Fortunately, the insulation requirements of a floor are not severe. Temperature differentials between house and ground are low, therefore heat flow by radiation is low. About all that is required is to keep the wind from blowing through. Here is a suggested floor structure, seen in profile:
The floor structure is put together this way, always working from the bottom up. First the beams are fastened to the footing posts. Next a layer of insulation board, which has been made for low heat flow at the expense of strength. Here its only structural purpose is to hold up the aluminum foil. Next comes the foil layer, which this time, to simplify things, will be shiny on both sides. The insulation requirement is not severe. A single layer will suffice, and keep the wind out as well.
Above the foil layer, you have a choice. If you have not been able to achieve the central plumbing core which will be described later, there needs to be a space for pipes. In this case, raise the cross-beams on spacer blocks located above the main beam, and drive on.
From the cross-beams on up, our floor is exactly the same as before.
Here is one more reason for building the floor before the wall.
In the next section you will discover that your wall, instead of sitting on the floor, is going to come down past it. Conventional floors are finished last, and require fitting all around. Yours is built first, hangs over at the edges, and is squared off with a power saw. Then comes the wall, with no crack showing. And now you know why the dew water falls onto the ground.
All of which leads us to wall building.
36. How to build a wall
Architecturally speaking, walls receive a lot of attention, because they are at eye level, both from the inside looking out and the outside looking in. Structurally speaking, walls are the easiest and cheapest part of your house to build.
The architectural concern with walls--the pictures that have been drawn and the pages that have been written about them--is an aesthetic matter. What you do to dress up the inside and the outside is your business, but I suggest that for the time being you do nothing in the way of "decoration."
In a post-and-beam house, the walls are just hanging there, with their principal function being to keep the wind out. They are supposed to admit controlled quantities of air and light. Nobody walks or dances on them; no snow rests on them; water drains out of them easily. Being vertical, their major heat control requirement is radiation and not conduction. Their area is relatively small. As structure, they are required to hold up nothing except themselves and a few pictures.
Walls, I repeat, are the easiest part of the house to build. The carpenter doesn't even have to bend over. Among all the many ways to build a wall, here is the profile, looking down, of my favorite wall assembly:
Having looked at the sketch, let's build it. This time we will work from the inside out, starting with the posts and working down past the floor, which, according to the preceding section has already been completed and squared off.
The first layer is what shows on the inside, at least until you get around to covering it up with whatever suits your fancy. My sketch shows it made of vertical boards or plywood. Holes are left for the doors and windows.
Since this first layer is nailed only top and bottom, into either the beam or the plate, it will seem perilously loose. At the opening for windows, where for the moment the boards are fastened at only one end, the wall will seem ready to collapse at the first puff of air. A nailing strip fastened at the bottom line of the windows may be helpful to the carpenter. It will serve more as reassurance than anything else, however, for it is not at all necessary to add stiffness to the wall--as you will see as the layers go on.
Next comes a layer of aluminum foil, shiny side in, running horizontally and overlapping from above like shingles. The wall at this point is practically waving in the breeze, just about stiff enough to stand up against the attack of the stapling gun that tacks on the foil.
Now we begin to stiffen it up with battens. A batten is a piece of almost-junk-wood, two or three inches wide and an inch (in quotes) thick. The battens are placed horizontally, two feet
apart. Some carpenters use short nails to hold them on, as I do. Screws, though taking more time, hold better and in some designs are worth the extra trouble. The door and window openings are trimmed with battens all around. Our waving wall has suddenly become a lot stiffer.
Then comes another layer of foil, shiny side out, and an inch of dead air has been trapped.
The next layer is a row of vertical battens. The builder now has to get his head in the game, because the batten location depends on the width of the exterior board it is to support. The wall is now stiff enough and thick enough to nail to, and we hammer away merrily (using nails of the correct length), placing board on batten--leave a little space--place another batten and another board--figure how to break even at the window openings--another inch of air has been trapped--the condensation line is established at the outer foil with drops running harmlessly to the ground--and the wall, now four inches thick, is so stiff it rings under a hammer blow.
Building a layered wall is an easy but exciting experience. I get carried away every time. The materials are inexpensive; the completed product is structurally and thermally sound; the random width exterior boarding, in addition to being an excellent weather surface, has given us an aesthetic chance at variety of line and texture.
At this point you may say, I know all about board and batten. That's shack building. Here is what you mean:
This is the board and batten you are thinking of, with the board put on first and the batten showing on the outside. It looks cheap, and is. All 1 do is turn the board and batten around:
By doing that I add another inch to the effective stiffness of the wall, trap another inch of air, provide a free drainage channel for the dew. The whole thing remains cheap, but it looks expensive. If you don't believe it, come and look at my house.
The lower sketch, showing vertical, random-width boards spaced against battens, is in all respects the best exterior wall surface I can devise for a house. It drains well, both rain water and dew water. It ventilates itself. So far as the years of my own life have let me see, it will last forever. It is economical to build. It is so far out in front that I personally wouldn't think of building anything else. With all these advantages, it looks good too.
So far as weather is concerned, the house is now live-in-able as soon as it gets some doors and windows. The outside of the wall is complete for all time. The inside is completed or not, as you please. The wood inner skin retains the virtue of adaptability.
You can move in, live there in creature comfort, and retain your option on what you want to look at. If you want to decorate, the walls around you are ideal for trial and error experimentation. You can drive nails, hang pictures, display driftwood, or draw pictures in crayon, with no harm done. You can cover one wall with colored burlap, paint another wall white or decide on panoramic wallpaper, mix a little plaster or put up a little section of tile. You can decide that between two posts is a fine place to build a cupboard, or shelves for the display of Quimper pottery.
That good old wooden wall is an invitation to let yourself go. It didn't cost very much to begin with, and the chances are you can't do it any harm. If you want to--as I hope you will-- you can just leave it alone.
37. How to build doors and windows
Here is the way the ordinary door is fitted:
How well this door keeps the wind out depends on the accuracy with which it is fitted into a frame. In warm, wet weather, when there is no need for a tight fit, the door swells up and sticks. In cold weather everything shrinks and the door admits an invigorating breeze.
Refrigerator manufacturers are much smarter about doors. They build them this way:
The moment you stop to consider it, I think you will agree this is the sensible way to build a door. It doesn't have to fit anything. It just closes, flat to flat, and there you are.
The domestic hardware people don't seem to have heard about the refrigerator-type door, so you will probably run into trouble getting hinges and latches that will work. When I can't find suitable hardware, I do this:
The next question is, which way should the door open, in or out? Well, one million out of one million house doors open in, and, flatly, every one of them is wrong. For once I find myself on the side of the building codes, which insist that doors, at least in public buildings, must open out.
The codes are based on one reason--rapid, unblocked escape from fire. There are many more reasons, all good, why doors should open out, and none that I can think of for their opening in. Here are some of the open-out reasons:
June bugs and mosquitoes collect on the door. Open the door out and they just sit there. Open it in, and happily in they come.
Comes the wind, pressing against the door. If the door opens in, it gets looser, maybe even blows open. If the door opens out, it gets tighter.
Comes the intruder, seeking admission against your wishes. The old "foot in the door" technique is useless when the door closes with the intruder's weight, not against it.
A door takes a lot of space, because there has to be an empty area somewhere into which the door can be swung open. If this space is inside, it costs you many dollars per square foot. If outside, it costs few if any dollars.
Without belaboring the dangers of fire, you will grant that getting into a house is never quite as urgent as getting out of it when things go wrong. Even something so minor as the cat being about to vomit.
If the weather door opens out, what becomes of the screen door? I have experimented with putting the screen door on the inside, opening in, but that doesn't work for the same reasons that the weather door doesn't work well that way.
The best of all solutions is the old-fashioned screened porch. If you don't like that name, we'll call it a "weather vestibule." It gets the arriving guest out of the rain, makes a place to put your overshoes and your umberlla, provides a chance to stamp the snow off your shoes or dry off the dog after a walk in the rain. It gives the mailman a safe spot to leave oversize packages, and it bewilders the mosquitoes who are trying to find a way in. There are a lot of comfort-inducing benefits in that list.
Assuming that we went a step farther and put the social-room door and the kitchen door in the same weather vestibule, the whole thing might look like this:
What happened to the good old "storm door?" You don't need any. The refrigerator-style door, with or without the weather vestibule, gives at least as much storm protection as two inset doors sitting back to back. I hope you have not forgotten to avoid putting any door where it faces into prevailing wind and snow.
I haven't said anything about how your door should look. Take your choice. They make all kinds. But I do want to utter a very loud cry about door widths.
A common standard width is thirty inches. Subtracting the stop strip, and assuming the usual situation where the door won't open all the way, you're lucky if you can clear twenty-seven inches. Yet many things are built to a standard width of thirty inches. A desk, for instance, is generally thirty inches wide and thirty inches high. You have a choice when the desk arrives; you can tear the wall down or send the desk back.
The refrigerator salesman asks, or should ask, about actual door clearance before he starts delivery. Appliances keep getting bigger. At least one door in the house should clear thirty-six inches. Not be thirty-six; clear it. This may re-
quire a little shopping to find a store-bought door wide enough. For the rest of the doors, a minimum clearance of thirty-two inches will admit most furniture. This can be achieved with a thirty-six-inch door, which, happily, is a standard width.
Less happily, I report that although fire-resistant doors could be manufactured for about two dollars more than the cost of those usually available, they don't seem to have caught on. Up to now I've been fabricating my own. Short of that, the solid plywood door is a good bet, because it's massive. The so-called "hollow" door is a buck or two cheaper, and it's firebait. Nor does it close with that pleasant, convincing, "I'm at home now" thump.
WINDOWS. Some while back I defined a window as a piece of glass
set in a wall for the purpose of admitting light and permitting
you to see out, though not intended to be opened for the purpose
of ventilation.
If you start with the wall structure described in the preceding section, here is the best way I know to get a lot of window for little money:
This is a carpenter's window, built right into the wall, using commercially available materials. It costs little if any more than a plain wall, without window.
First the carpenter builds a box, slanting the horizontal pieces a little downward so that whatever water collects on them will drain off. The box becomes part of the wall structure.
Next he cuts up or buys a lot of strips, about a half inch thick by five-eighths wide, and nails them in place so that the glass will have something to lean against. As we have learned earlier, the strips are to slant out at the top by about three degrees, or in carpenters' language about one inch in twenty.
Then the panes are set in and held in place by another set of strips nailed to hold the glass on the inside.
That's all there is to making windows. It seems almost too ridiculously simple to be any good. Perhaps because the window is simple (and we have come to believe that windows are complicated) many questions will be raised. Though it took only one minute to describe how to build a window, please bear with me during the many minutes that follow while I answer, not necessarily in the order of frequency or importance, some of these questions.
Question One: what happened to the putty? Didn't you know
all glass is set in putty? Answer: yes, I knew it. When I began
to build windows this way, I put glazing compound on both sides
of the glass. That was quite a while ago. Then I got tired and
put it on the outside only, and I asked every carpenter I knew
if he knew what the putty was for. No answer. Getting even more
tired, I quit using putty.
As far as wind coming through is concerned, I can't feel any difference. As far as protection from breakage is concerned, the only pane that has broken was the one smashed the time we got bombed by a partridge who was fleeing a hawk. (Picked up broken glass for a week.) I have concluded that putty got started in the days before power saws, when it was easier to stick the glass in place than to saw up another set of strips.
Question Two: why does the glass lean out at the top? Isn't
that a lot of trouble? Answer: it is no trouble at all if the
window is built in place. It avoids the use of rabbets, moldings,
and close fits which make the conventional window expensive. Why
is it tilted? Better vision, less glare, less dirt.
Question Three: how big are these panes, anyway? . . .
Well, the smaller the pane the more material required to frame
a given area. As a rule of thumb, it would seem that anything
smaller than twenty by thirty inches is too small to fool around
with.
At the large end, we have two things to think about: how large a piece of glass can one carpenter handle with comfort; and how big a piece can conveniently be replaced when it gets bombed by a partridge or little league home practice. My suggestion, not necessarily binding on larger and stronger carpenters, is something around thirty by forty-eight inches as a reasonable maximum.
Question Four: you say thirty by forty-eight. How come?
Why not forty by forty, for instance. . . . The wider pane breaks
easier and in most places doesn't look good. Remember that the
window, being at eye level and extremely visible from inside and
out, is a prominent part of your architectural detail, perhaps
second only to the roof line in importance. The so-called "golden
rectangle," that four-sided shape most restful to the human
eye, is sixty-two somethings by thirty-eight somethings, or a
little less than five-eighths as wide as it is long.
There is one little catch. Hang an exact square on the wall, and a hundred sets of eyes out of one hundred will declare it to be higher than it is wide. This is because the eye muscles make harder work of vertical movement than of horizontal. Therefore, if the long side of our rectangle sits horizontally, it can be fairly skinny, say, twenty-four by forty; but if it is installed vertically, we fatten it out to around twenty by thirty, and get the same effect. Graphic artists execute these proportions without necessarily knowing why. The rest of us can produce a better-looking result if we know the rules.
Question Five: how can I afford to buy all this plate glass?
. . . Who said anything about plate? I use the so-called double
strength, but otherwise ordinary window glass. It is rolled, not
poured, and is very slightly wavy. Looking straight through, you
can't see the waviness, but at an acute angle you can. Some people
claim this bothers them. If they want to pay more for plate glass
panes, my sketch doesn't change. All I say to them is why don't
they rebel against the really acute distortions in the curved
windshields of their automobiles?
Question Six: speaking of plate glass, what's wrong with
these enormous single windows I see in all the magazines? . .
. Nothing, except that I don't like them, and I don't think you
will either after you've lived with them for a while. The caption
beneath magazine pictures tells how nice it is to feel that you
are living outdoors. This is obvious nonsense. Sometimes it's
nice and sometimes it isn't. The first function of a house is
to provide shelter from the outdoors, available at your will.
Let's look at my big window, as sketched, with six medium-sized panes instead of one great big one. The first contention of the big-window advocates is that the frames interfere with that old outdoorsy feeling.
Here is a sketch of anybody, male or female,
standing and sitting. Since all standard chairs are about the same height, 17 inches, and since people don't vary much from torso to torso, the eye height of almost anybody sitting down, is 47 inches, give or take a couple of inches. When people stand up, the difference increases, but the average eye height is about 64 inches, and 90 per cent of the world's people look out at a level not far from that.
The standard table height is 30 inches, rarely higher, sometimes an inch or two lower. Since we wish to preserve the option of putting a table against the window for flowers and stuff, to look good the window will begin at 32 inches above the floor.
Remember, please, that our field of vision is fairly flat, since we look sideways a lot easier than we look up and down. Also the normal field of vision, at rest, is inclined a little below horizontal, because we all carry our heads tipped a little bit forward. Starting at 32 inches, a 24-inch pane puts the divider at 56 inches. With your eye at or anywhere near 47 inches you can see out perfectly while sitting down.
Stand up, and unless you're very short, the divider still isn't in the way. At the other extreme, in order not to be able to see comfortably out of that upper pane, you would have to be at least seven feet four inches tall.
The vertical dividers are equally unnoticed, but for a different reason. When you look out, your eyes are focused on distance. Anything up close becomes a meaningless blur, and your eyes swing easily past the vertical dividers without even noticing them.
All I have argued so far is that the multiple-paned window is no worse than the single sheet of plate glass. Now I want to demonstrate why it is not only cheaper, but better.
Comes a bad day, or darkness, and that out-doorsy feeling is not for us. We turn our eyes away from an unbroken expanse of glass, hoping to avoid its coldness. Our eyes are no longer focused on distance, but on near things. We seek the feeling of enclosure, and our eyes rest gratefully on every physical thing that tells us the walls of our house are secure.
As a sub-question, you may point out that the magazines show lots of glass going clear to the floor, and isn't plate necessary in this case? To me, glass to the floor is inexcusable, except for the rare instance where the view lying far below our normal line of sight is too good to be missed. Even in this case, glass to the floor must be used with caution to avoid a feeling of insecurity.
Look here:
This sketch explores the question of whether to start the glass at 4 inches up, or at my recommended 32 inches. You can see that the glass at the bottom does very little toward letting winter sun into the house. It's the glass at the top that counts in winter. In summer, glass to the floor requires more overhang to keep out the sun.
Glass to the floor does not trap more winter sun, but it does let more heat escape at night, radiation being proportional to area. It destroys wall space that otherwise could be used for tables, chairs, bookcases. Even if I live on the edge of a cliff and want to see the valley below, I'm willing to stand up to do so, preferring the feeling of fence between me and the sudden drop.
To summarize, I can't see how glass to the floor does any good. It may, instead, do considerable harm.
I'm trying to save you money, which is my apology for such a long
answer to a simple question. To spend has become reasonable, accepted,
compulsive. Not to spend seems to be the proposition which now
requires the longer argument. Nevertheless, the way to save money
in a house is to search out the things we have been told we need,
but don't. If I have succeeded in con-
vincing you that you neither need nor want enormous plate glass windows, I have saved you a good many hundreds of dollars right there. The answer to your next question may save you a lot more.
Question Seven: what about double glass for insulation?
. . . Here we are really talking about money, and money which
in some cases has been spent to do more harm than good. Once again
we are discussing a widely advertised product that everyone tells
us we can't live without.
My rejoinder is that I can live without a mortgage, so let's begin in the same old way to find out where we don't need double glass.
The obvious place where you neither need nor want double glass is on the south side, where at least half of your glass is going to be anyway. Probably not on the east side either, but that depends. If double glass keeps heat in at night, it keeps it out equally well in the daytime. In the course of a midwinter day and night you might break about even. In the meantime you have suffered, not only bankroll shrinkage, but a 20 per cent loss of vision, because every glass surface, inside or outside, knocks off about 10 per cent.
A better scheme for big windows on the south side involves use of curtains.
You intended to have curtains anyway. I ask that they become part of the insulative structure. The sun shines and the curtains are open, admitting heat. At night, you drop or pull them closed. Both the insulative and emotional requirements have been met. Not only have you won on heat, maintenance, and original cost, but you can go into the pipe and slippers routine without that black, blank wall of glass staring at you on a winter's night.
Double glass may be of benefit on a west or north wall, where we normally would not have many square feet of windows anyway. Even here it is questionable whether double glass will ever, in your lifetime, save enough heat to repay its original cost. Certainly it will not if you are willing to go to the trouble of pulling a curtain across it at night.
I can think of one situation where double glass is the right answer. Suppose that for good and sufficient reason you do indeed want to sit before a big northwest-facing window, gazing at the moonlight, without wearing a blanket. Here double glass wins.
Question Eight: what about condensation on the inside of
a single pane window? . . . Those beautiful frost patterns you
see on the inside of windows of a winter morning are a visual
illustration of the condensation line, which I explained earlier.
The same deposit of water has taken place inside your walls and
roof, but you can't see it so you don't worry about it. That same
frosty dew, when deposited on your windows, soon melts and runs
down, changing from a thing of beauty into a puddle on the window
sill.
The puddle is undesirable. As with all of our undesirables, the answer is to get rid of it or get it out of sight. There are at least two effective ways of dealing with window condensation.
In the sketch at left, the strip of wood holding the inside bottom of the glass has been beveled to catch the water. Before putting that last piece in place, your carpenter drilled three or four tiny holes through the bottom board into the inside of the. wall, which was already loaded with condensation and has been built to drain. Exit the puddle.
In the sketch at right, the bottom piece of wood, beveled in the same way, retains the puddle but keeps it out of sight. Presently the water evaporates, and as it vanishes the puddle does its tiny bit to relieve the low humidity in the room.
VENTILATORS. You will remember that in the ideal situation, the
ventilators are placed low down on the cool side; high up on the
warm side. Since your carpenter is going to build the windows,
he might as well build the ventilators too. Then, in that ideal
situation, you might wind up with this:
Here the carpenter has included the ventilator frame along with the window frame.
An alternate, space-saver arrangement for the north side looks like this:
Here we have placed a ventilator at each end of the frame, with three panes of glass in the middle. This scheme, though departing from the ideal thermal arrangement, makes a lot of emotional sense. With the ventilators open in the summer, you do, as the magazines say, live outdoors. Close them, and your feeling of security at the line of sight has been increased.
Once we have decided that windows and ventilators are two different things, the location for ventilators, being independent of vision, is endless. We can place them where we like, hinge them in or out, up, down, or sideways. A ventilator, essentially, is a frame, a board, two hinges, a latch, and a piece of screen. The screen stays there, with no nonsense about taking it down in the winter.
If the opening happens to be large in proportion to the rest of
the wall, we will begin to worry about heat loss. I build my large
ventilator doors like this:
Two layers of wood, screwed together crossways with foil between, are dimensionally stable, inexpensive, fairly non-conductive, and fire resistant. For very cold climates (or very coldblooded people) use two doors, one on the inside of the wall, the other outside. Open the outside one in the spring, close it in the fall. You may call the outside one a "storm ventilator" if you like.
Ventilator areas can be surprisingly small provided they have been properly located with the inlets on the low, cool side and the outlets on the high, warm side. In building my own house I framed in three times as much ventilator area as has ever been used.
Specific figures at this range are always dangerous, but you need a rule of thumb with which to begin your own on-the-spot engineering. The outlet ventilator should be at least double the size of the inlet. Try making your inlet or cold side openings about one-twentieth the area of the wall they are in, your outlet or warm side openings about one-tenth the area of their wall.
You will find that the size of the openings required to circulate air will be about one-fifth the area of glass required to admit a satisfactory amount of light.
With the fixed window to see through and the ventilator to breathe through, you will have more light when you want it, more air when you want it, and better heat control than you would have with conventional windows. And for less money. The ball is now tossed to you, because you will have to do your own engineering to get light and air where you want them.
38. How to build partitions
Advice on partition-building divides itself neatly into three don'ts.
Don't build a partition as if it were an outside wall.
Don't use a partition to hold up the roof.
Don't build it at all if it really isn't needed.
IT ISN'T AN OUTSIDE WALL. The prime function of an outside wall
is to protect the family from the world and the weather. The prime
function of an inside partition is to protect the members of the
family from each other.
To re-phrase, the outside wall must offer physical and thermal protection; the partition should offer visual and acoustic protection. The only time you need a partition is when you don't want to see somebody or hear somebody.
In spite of this perfectly obvious distinction between a wall and a partition, carpenters cling to their habit of building partitions as if they were outside walls. The convention is to use the same studding timbers and to complete the job with some sort of skin, plaster and decoration on both sides. This practice is used for partitions, clothes closets, linen closets and even the places where we hide brooms. Ironically, though partitions built this way are expensive, they aren't even good at their job.
To provide visual and acoustic protection, a partition should be a skin which is opaque to light, and a barrier which dissipates sound. Translated into structural terms, the partition ideally looks something like this:
Since the partition supports nothing, there is no need for strength. Stiffness is undesirable, because the stiffer a partition is the noisier it will be. Heat conductivity means very little, the worst situation we can imagine being a seventy degree living room on one side and a forty-five degree shop on the other. You will recall that heat flow goes by the square of the difference. In fact, if noise reduction is no object, there is no reason for the partition to be more than one opaque layer thick, just strong enough to hang pictures.
You realize that simply by being thick, a partition is robbing you of expensive interior space. The conventional partition chews up one square foot of space in just a little over two running feet of length. Therefore the single skin partition has much in its favor.
If, however, you object to the sound of trombone practice, squeaking bedsprings or the flush toilet, two skins are needed for a partition, if only to hide the acoustic insulation. To get the most sound absorption for the least money, the skins themselves will be soft-textured and not very stiff. The separators which hold the skins apart will be as light and infrequent as possible. The fluffy stuffing can be made of anything from rock wool batts to old egg boxes.
In choosing your materials, remember that a rigid structure is elastic, and thus transmits sound. The probably unacceptable goal would be two layers of burlap separated by cotton batting. A partition built that way won't transmit much of anything.
A closet full of clothes makes an acceptable approximation of these specifications. A bookshelf full of books does fairly well, and even a storage cupboard holding miscellany is not too bad. Therefore I suggest you put many of your partitions to work holding things. Closets are wonderful, provided they do not pretend to be outside walls and provided you can move them around.
IT DOESN'T HOLD UP ANYTHING. I suggested earlier that it makes
sense to build four walls and a roof, move in, and find out by
living there where the partitions should go. I think partitions
should be made to justify themselves. They should by all means
be easy to move, so that if a partition turns out to be in the
wrong place, you can fix it.
In this section we started to build your house. We put the
roof up first, before the floor or the walls were there, and of
course before the partitions. We didn't build this way in order
to avoid load-bearing partitions, we did it because it makes sense.
Because it was done that way, however, you are left free to partition
as you please from here on.
IF IN DOUBT, DON'T. My wife amuses her friends by telling them
of the time when our flush toilet was surrounded by three doors
propped together. Things are different now. The partition between
bathroom and kitchen is all of five feet high, with cupboards
on both sides, to boot, while early morning conversations proceed
as smoothly as ever. We have thoughtfully provided a portable
radio for the benefit of guests who remain acoustically conservative.
Naturally I don't insist that everyone adopt this relatively free-and-easy approach to partitioning. I do insist in all seriousness that partitions are not too good things to have if we can get along without them. Too many partitions promote darkness, bad acoustics, and inconvenience. It is much easier to add a needed partition than it is to take a superfluous one away.
So much for the don'ts. Now to the do's. Partitions are used to
define rooms. The real-estate agent asks you how many rooms your
house has, on the absurd assumption that an eight-room house is
worth more than a six-room house. What you want is a house that
you can describe to the real-estate agent as eight rooms, but
to the tax assessor as six.
This we can do by using closets as partitions. The conventional closet is a full-partitioned, two-by-four studded, plastered inside and out room, too big for cats and too dark for chickens. Its walls are exactly as thick, stiff, and expensive as the outside walls of the house itself.
The movable closets on the opposite page can be used for clothes, or translated as you will into bookcase, kitchen cupboard, linen shelf or games storage. Built to beam height, it becomes a complete wall. It absorbs sound, stops vision, is