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House Blueprints Home 1. Building a house 2. Selecting the lot 3. Build a House 4. House Plan 4a. House Plan (II) 5. Kitchen Plan 5a. Kitchen Plan (II) 6. Drawing plans 7. Financing 8. Quality House? 9. Getting it built 10. Construction Tools 11. Basement 12. Materials 13. Slab building 14. Stake out 15. Building permits 16. Excavation 17. Foundation 18. Good concrete 19. Framing 20. Room framing 21. Cornices 22. Roof coverings 23. Wood Floors 24. Heating systems 25. Plumbing 26. Wiring 27. Painting |
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Chapter 22. Roof Coverings
The purpose of a roof is to keep the weather out of a house, an umbrella on a wet day and a parasol on a hot day. The kind of roof that is best for a particular house will depend on many things. The preference of the owner should first be considered. Although good roofs are sometimes made of grass, palm leaves, or cedar bark, these are not commonly used in America.
The principal things to consider besides the taste of the owner in selecting a roofing material are the first cost, the appearance of the roof, how long it will last, how much maintenance or upkeep it will require, how fireproof or fire resisting it is, what insulating value it has, and most important, will it really keep the house dry even during driving heavy rains or periods of excessive snow.
How steep should a roof be? That depends on the effect you want. The steepness, or pitch, of a roof will determine what type of roofing should be used. A roof composed of small pieces of material, as shingles or slate, should seldom have a slope of less than 5" rise per foot of horizontal distance covered. See detail.
One thing should be noted carefully: it is not the steep roofs that leak. When it comes to keeping out the rain, the steeper the better. This has, however, practical limits; we do not want a house to look like a church, and we do not want the roof area to become too large. We may want a rather low appearance to the entire house, and a steep roof would be out of the question. Let us be reasonable about it, and if at all possible, keep the pitch at least as steep as 41/2" rise per foot, and preferably 5" or more; that is, if we want a roof made of shingles, slate, composition shingles, rigid asbestos shingles, or similar small pieces of material.
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| Hip roof with shingles on roof ready to nail in place. Note spacing of sheathing. Rafters are cut off square giving an angle to the facia or finish boards at eaves. |
If a really flat appearance is desired, it will be necessary to use a built-up roof. Many roofs with a slope of less than 1/4" per foot are giving satisfactory service, but they might do better with 1/2" per foot slope. These flat roofs are what are called built-up roofs. That is, they are made of several layers of roofing felt cemented together with asphalt or coal tar pitch, and covered with a layer of gravel to keep the wind from disturbing the roof, and to keep the sunlight from causing deterioration of the asphalt and felt. This roof depends for its effectiveness on its being one piece of impervious material. Roofs of this type should never have a pitch greater than about 21/2" rise per foot, as they tend to slide down the slope when they expand on hot days, and are not strong enough to pull themselves back into shape when they contract at night.
It requires more care and skill to put on a good flat roof than it does to put on a steeper roof. I do not say that a flat roof will always leak, but I have had a lot more trouble with them than I have had with steep roofs.
Local customs, the materials available, the preference and prosperity of the owner, and the type of house, will have an influence on the type of roof selected.
High class workmanship and meticulous care about the details are the things that make a good roof, fully as much as the choice of materials.
In wet climates where it really rains, and rather often, it is hard to beat a roof of wood shingles. These can be of cedar, redwood, or cypress; but in many sections of the country builders feel that genuine red cedar shingles cut with the grain vertical are the most satisfactory. See detail illustrating what is meant by vertical grain.
Shingles should be thick at the butt. The most popular thickness is expressed as 5/2, meaning that the butts of five shingles will measure 2" in thickness, so that each shingle is 2/5" thick, at the butt, tapered, of course, to less than an eighth of an inch at the tip.
These shingles should be put on with galvanized nails, as the blued or bright nails will soon rust and let the shingles blow off. A good cedar shingle roof should last at least twenty years if properly put on and treated. Treating will be explained in the chapter on painting.
Cedar shingles must be vertical grained as mentioned above; that is, the surface of the shingle should show the edge of the grain. Flat-grained shingles are not worth putting on as they tend to split, and usually in places to permit leaks. They can be used for undercoursing when shingles are put on walls.
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Expose wood shingles about 41/2" to the weather on the flatter roofs, and 5" to the weather on the steeper roofs. Note that the roof must not be too flat for shingle roofs, minimum rise 5" per foot of run.
Shingles are laid with a small space, about 1/4" wide, between the shingles. If they are laid too tightly together, they will buckle when they get wet, look unsightly, and give opportunity for the rain to blow under them.
Always put two nails in every shingle, no matter how wide or narrow. Split all shingles over 8" in width, as they will split of themselves if you don't do it, and they may split in the wrong places.
To start shingles, stretch a line along the lower edge of the roof about two inches out from the cornice. To do this put a shingle on at each end of the roof, and let it project the required two inches beyond the cornice. Then with shingle nails in the ends of these shingles, tie the string and stretch it tightly.
This will give you the line for the first course of shingles. See detail. Always double the first course of shingles; that is, lay a second course directly on top of the first course, with the lower ends even so that you have two thicknesses of shingles at the start.
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Then measure up 41/2" or whatever your exposure is to be and strike a chalk line, or lay a straight piece of 1" x 6" on the correct line to mark the bottom of the next course. Put the next course of shingles to this line, or against the straight edge, and nail them in place. Put the nails about 3/4" from the edges of the shingle, and far enough up so the next course will cover them. Give the shingles a side lap of at least 11/2".
Sheathing does not need to be tight together for shingles. Do not use roofing paper under wood shingles. Rough split or cut so-called shakes make a more spectacular roof than regular wood shingles, and because of their extra thickness may last slightly longer. Because of their roughness, however, and since they do not fit as tightly together, they cannot be considered much superior to the ordinary-sized shingles. Some people, though, like the rough appearance. They do make a good roof.
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| View of side of house framing. Note barge boards cut off an inch above roof so shingles can go under the end of it. Roof sheathing is spaced. Electric wiring in metallic cable (B-X) runs from one box to another. |
For asphalt or composition shingles the sheathing must be tight together. If you want a projection at the eaves, it will be necessary to support the asphalt shingles, as they are too limber to project by themselves. An easy way to accomplish this is to use a double course of wood shingles at the eaves, giving a projection of about 11/2"; the asphalt shingles can then be made even with the wood shingles and will be adequately supported. This will get the drip far enough away from the cornice.
To get a smooth effect, some shinglers place the first course of asphalt shingles with what is normally the top edge toward the bottom, then place the next shingle immediately on top of this one in the regular way to start the pattern of the shingling.
Care should be taken to keep the pattern of the roof running in straight lines, as the regular size of the composition shingles make any deviation very noticeable. If you get started right, no difficulty should be encountered.
Nail the composition shingles with 7/8" galvanized roofing nails, or with other size if recommended by the manufacturer. Directions for placing composition shingles usually come in the bundle with the shingles.
It is a good precaution to put a layer of 30 1b. felt on the sheathing before placing asphalt shingles.
The principal disadvantage of wood shingles or asphalt and paper shingles is that they are not fireproof.
The fireproof roofing materials include such materials as slate, tile, rigid asbestos shingles, copper, and galvanized iron.
In the eastern part of the United States, slate is extensively used. The average builder would doubtless be better off to hire someone experienced in the application of slate roofs to put this roof on for him. Be sure it is nailed with rustproof nails, as copper or galvanized iron. For a roof as permanent as slate, copper flashing and valleys should be used. Aluminum is now coming into use as an auxiliary roofing material, and its use for flashing and valleys might well be considered. Slate makes an extra good roof, if properly installed, as it is permanent and is not so much affected by the weather as the organic materials. Since large hailstones sometimes break the slates in a roof, no material is the perfect roof.
In some areas tile roofs are used successfully. Although well-burned clay tiles do make an excellent roof, the roof frame must be very strong, because of the weight of the tiles. Tiles made of cement are also used. There are two general types of roof tiles used in this country, French tile and Spanish tile. (See illustration.) Either type is good if properly laid and secured in place.
In Japan and many parts of China and Korea tile roofs are the accepted thing. These roofs are much more permanent than wood or asphalt shingles. It is partly a question of balancing the first cost of the roof against the fact that the cheaper roofing will have to be replaced much sooner than the more permanent materials. If it takes all the money you can get together to build the house at all, then use the cheaper roof; perhaps you will be more affluent when the roof needs to be replaced.
If you wish a tile roof, it might be wise to get a professional tile roofer to do the work, rather than trying to put it on yourself.
Rigid asbestos shingles are much superior to the ordinary pliable asphalt shingles, as they will last many years longer and they are fireproof. They also make a good-looking roof. Be sure to nail them with rustproof nails. They cost much more than wood or composition shingles. The process of laying them is not complicated. Begin with a double layer at the bottom and shingle as you would with regular shingles, being careful to follow the manufacturer's directions.
If you prefer a roof that is nearly flat, then you will select a material that is built up so that it forms one impervious sheet over the entire roof area and is not composed of many small pieces the way the previously considered roofs are made.
These flat roofs are composed of several layers of asphalt-saturated paper cemented in place with hot asphalt or coal tar pitch mopped on between the layers of paper. Sometimes the first layer is held to the roof boards by dripping spots of hot asphalt over the roof area and rolling the paper immediately over this hot asphalt. It used to be the custom to put a dry sheet of building paper over the roof area before the first layer of roofing was placed to prevent the roofing from sticking to the boards, but some roofs have blown off and now it is considered good practice to stick the roofing to the boards with a very light coat of asphalt. The first layer is also nailed in place, at least around the edges.
A built-up roof is composed of at least three layers of 15 lb. felt, each layer well mopped on.
A person putting on his own built-up roof may find it convenient to use a roofing pitch or asphalt that can be applied cold. Ordinarily the asphalt is heated and applied to the roof while still hot. This is a great bother to a person working alone, and the danger of getting a bad burn is always a possibility, while the material that can be applied cold is easy and safe to use, although it costs a little more money.
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A metal strip is usually put along the edge before starting to apply a built-up roof. Then start with a strip of roofing felt a foot wide and fasten it securely in place. This is often done by nailing, but as mentioned above, many roofers now sprinkle drops of asphalt over the area, each drop forming an attachment for the roofing and thus save much of the nailing ordinarily required. In districts where wind is a problem, be sure the roofing is well fastened in place. After the piece one foot wide is in place, it should be followed by a strip two feet wide, also placed at the same starting point. Then follow this with a full-width strip, three feet wide, also starting at the same place. This gives three layers at the starting point for the first foot of roof. Of course, you have mopped each piece in place with plenty of asphalt. The next sheet is put on so as to leave exposed about 11" of the previous sheet. Continue on up the roof exposing each time 11" of the previous layer. See detail. In this way you will get three full layers of roofing with asphalt between the layers all over the entire area of the roof. For a really good roof you may want to add another layer or two, lapping the sheets about two inches, and mopping each piece down thoroughly as you go.
Then mop on a heavy layer of asphalt and immediately place the gravel on the roof so it will stick to the fresh asphalt. Use about 3 lbs. of gravel to the square foot. The grayel can be all of one color, or you can put on a layer of one color and put larger rocks of a different color on afterward. Large rocks can be put on to give an "arty" effect, but be sure they will not roll off and hit someone on the head. Small blue rocks followed by larger white rocks can make a very artistic roof. Common gray gravel can be used to make a good-looking roof if carefully applied. Put on the kind you like and can afford.
The rocks have two purposes, to make the roof more windproof by adding to its weight, and to keep the sunlight from causing deterioration of the asphalt or pitch.
Fenestration
A very important part of every house is the fenestration, which means the selection, size, and arrangement of the windows. Windows do much for the exterior appearance of a house and can make a room livable or intolerable, depending on where they are placed and how they operate.
There are three general types of windows: those that slide up and down, those that slide sidewise, and those, called casements, that are hinged at the side and swing out or in.
The ancient and honorable double-hung windows that slide up and down have many things in their favor. They are weather tight, if properly installed, they operate easily, and they are not expensive. The ones that are fitted with weights and cords that run over ball-bearing pulleys are the most satisfactory. So-called sash balances of various kinds are on the market, which seem to work rather well, especially when they are new; these work on the principle of winding and unwinding a spring. Be sure the windows are sufficiently counterbalanced in some way so that they operate freely and easily.
The windows that slide horizontally are at the moment more in favor, perhaps because these new aluminum windows lend themselves particularly well to the modern house. If they move on nylon rollers they seem to be rather satisfactory; but they are not as windproof or dustproof as the double-hung wood windows.
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The fact that the aluminum does not require painting partially offsets the slight additional cost. \i you consider the repeated paintings that wood windows will require, the aluminum will be cheaper in the long run.
Many people feel that the metal windows go particularly well with modern type houses and fear that the wood looks out-of-date. This is largely a matter of opinion.
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| Aluminum, window nailed in place with flashing around it. Flashing is heavy waterproof paper. The window is nailed to the studs here. If sheathing is used on outside of frame, the aluminum window frame is nailed outside of the sheathing. Flashing similar in any case; it keeps out the wind and driving rain. Double flash at the top of the window, using rustproof metal on the outside, arranging it so water will not run toward the inside of the building. |
In a very cold country the wood is less liable to collect frost on the inside, as the metal is a very good conductor of heat, and will conduct heat rapidly to the outdoors on a cold night and may collect considerable frost on the inside from moisture condensed from the warmer air of the room,
Much depends on the taste of the home owner, Either type of window will last as long as other parts of the building. If you like one kind, use it. The size and placement of the windows is more important than the material of the frame.
Glass blocks can be used to let in light and for decorative purposes, but they do not help with the ventilation of a room, which must be provided in some way for every room.
If the bathroom window can be fitted with a piece of glass that is translucent, but has a surface texture that does not transmit an image, it will save a lot of curtaining, which is often in the way in a bathroom. This glass is known as rolled glass, hammered glass, or obscure glass, and is not too expensive in the simpler patterns.
Casement Windows
Windows that swing in or out have a few advantages, but they tend to be in the way. Those that swing out are easier to make weatherproof, and are usually less in the way than those that swing in. When you hinge a window at the side or at the top and can open it wide, you get the full size of the opening for fresh air, but when you open a sliding window you get only half the opening for air circulation. If a window is mostly for ventilation, then the casement (hinged) type will be more effective. But casement windows are not noted for their tight fit and ability to exclude dust, water, or cold. Although weather stripping often is helpful in making them tighter, it can also make them more difficult to operate.
Large windows and picture windows are better put in so they cannot be opened. If plate glass is used, or the less expensive crystal sheet is selected, a window as much as 10' in one dimension is possible. The glass must be bedded in putty and set so it does not touch the metal frame at any place, or a crack is probable within a year or two. Some people have had better luck to set the large fixed piece of glass in a wood frame, fastened in place with wood stops; of course, the glass is bedded in putty in either case.
Where a large fixed piece of glass forms the principal window in a room, remember that every room also needs a window or two that can be opened. The most common rule in use in America today demands that the window area in any room must equal at least 1/8as many square feet as the floor area, and 1/2 of this must be openable. So if your room is 16' x 20' it has 320 sq. ft. of floor area, and must have 40 sq. ft. of window, and 20 sq. ft. must be arranged to open. You may have as much window as you wish, but the 20 sq. ft. is all that must be openable. A room that is not properly ventilated can be very uncomfortable on a hot night.
Another invention to serve most of the purposes of a window is the movable louver or jalousie. This consists of a series of horizontal strips of wood or glass that swing in such a way that light and air can come through them, but they can also be closed, the one above laps slightly over the outside of the one directly below it. They are reasonably waterproof, most of them let in plenty of fresh air, a feature that is good in many tropical climates. They also let in a great deal of dust. They are not too difficult to operate if fitted with a good quality of hardware, and are attractive in appearance when something different is wanted. I have installed a great many of them in the tropics with excellent results, but I have grave questions as to their suitability in colder climates, and I know they are not satisfactory in dusty places.
Glass is a good conductor of heat, and the more windows you have and the larger they are the harder it will be to heat your house. Air comes in around the windows and brings cold in with it, or goes out around them and takes heat out with it. The better the windows fit the less transfer of heat will take place. Weather stripping helps to make windows more airtight, but since people need a certain amount of fresh air, perhaps the small amount of infiltrating air is just what we need. In very cold weather storm windows would help to keep in the heat.
A great deal of heat can come in through the glass if the sunlight strikes the window. This can be largely prevented by using draperies with light-colored linings. The aluminum-treated coat lining called "milium" helps to reflect the heat back when used as the lining of the draperies.
A house that is well lighted is a more pleasant place in which to live than one that is dark and dingy. The extra expense of proper windows is more than compensated for by the extra livability of a well-lighted house.
Double glazing is sometimes used to reduce the amount of heat that escapes through the glass. In very cold countries this would be a worth-while investment, but in the warmer parts of the nation like the Pacific Coast, many of the southern states, and Florida the extra money would be largely wasted.
One of the problems with double glazing is the condensation of moisture between the two panes of glass. If you get the kind of glass that has a partial vacuum sealed in at the factory, you should have no trouble, but just putting two pieces of glass, with a space between them, in one frame could lead to difficulty.
All windows that open should be screened in most parts of the country. Screens are made of galvanized wire, painted black wire, aluminum, bronze, copper, and plastic. For ordinary jobs the galvanized wire is perhaps the most commonly used, but aluminum screen is coming into wide use. Bronze screen, which is usually considered the best, is also expensive. Some of the new plastic screen, coming into rather wide use, seems to be satisfactory.
Whatever kind of screen you use, be sure it is fine, at least not less than 14 mesh to the inch, perhaps 16 would be better. If it gets too fine, it retards the circulation of the air through the window; some window screen has as many as 18 wires to the inch, which is the finest that should be considered for use in a house.
Screens may have either metal or wood frames, and some of them called "tension screens" have bars at the top and bottom, and no frame at the sides.
Screens should be detachable from the inside for ease in washing the windows. Sometimes screens are made to be interchangeable with storm windows, so that storm windows are taken down in the spring and the screens are put up and the reverse procedure occurs in the fall.
The back door is often screened, or sometimes it just has a screened section in it. Many builders omit the screen from the front door as they feel that it does not improve the appearance of the front of the house, and that the front door does not stay open often enough to make a screen necessary. In sections where mosquitoes or flies are bad, a screen should be used, but local conditions will determine the need. This is something that could be added later if the need became apparent.
Glass
Glass comes in several thicknesses and qualities. The most expensive and undoubtedly the very best is called "plate" glass. The surfaces of plate glass are polished with abrasives after the glass is cast. This glass can be bought in several thicknesses. For small windows 1/8" is used, but for large picture windows 1/4" is the thickness to use.
Crystal sheet is heavy flat drawn glass about 7/32" thick that is widely used for large windows. Since very few people can tell the difference between this glass and plate, for an ordinary house it should be good enough. If you have such an exceptional view that you want to make sure that none of the view is distorted, use plate glass as the crystal sheet may in places have a slight waviness or other minor defect that might annoy a very fastidious person.
For ordinary windows use "B" grade flat drawn double-strength glass. The single strength is heavy enough for small panes, but the larger windows at least should have double-strength glass.
In speaking of windows, or any other openings in a wall, the width is always given first, then the height. If you give the height first, you will confuse the carpenters and they may frame the openings so the windows will not fit in them.
In some places the full size of the finished opening is used as the measure of a window as 36" x 54", for a double-hung window. In other places only the glass size is given, which for the above window would be 32" x 24". You will note that the size of only one piece of glass is given, but if this is indicated as a double-hung window, the builder will know that there are two sashes each with a piece of glass of this size. The 2" of wood on each side and at the top, with three inches at the bottom and 1" between the two sashes will build up the size to that indicated at first.
If you live in an area where the glass size is used, you can get windows in almost any size so long as you keep the glass in even inches, as 20", 22", 24", etc.
In places where the outside measurement is used, the sizes increase by 6" jumps, as 2', 2'-6", 3', etc., in both horizontal and vertical measurements.
Since the aluminum windows have various kinds of sizes, it is advisable to get the windows before making the openings to insure getting them exactly the right size.
The wood windows require that frames be made for them and placed in the wall. These frames can be bought ready cut, or ready assembled complete from the lumber yards, or you can make them yourself if you have time, but you might not save very much in doing so.
Be sure to put thick paint in the joints of any woodwork that is to be exposed to the weather. The place where the sides of the frame join the sill is particularly liable to leak, if not carefully put together. See details.
The aluminum windows come complete, and all that is necessary is to nail them in place in the frame of the house. The sills should be protected from the plasterers, who will most certainly fill them with plaster if possible. This plaster is very difficult to remove completely from aluminum. Paper and masking tape to keep the plaster off is much easier and better than trying to remove the plaster once it has hardened in the grooves of the aluminum frame.
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