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Construction Materials - Practical Options for your New Home
Materials of Construction
Most houses are built of lumber, as it is not very expensive, is readily available, is
strong and durable, and is easy to work. Ease of working is perhaps the most
important property as far as the amateur builder is concerned. A saw, a hammer, a
hand axe, a square, a plane, and a few chisels will equip a person to make almost
anything out of wood. Wood can be securely fastened by the simple process of
driving a few nails; no other material is so easy to fasten. A little glue placed
between two pieces of wood and pressed for a few hours will weld them securely
together. Steel requires elaborate welding or riveting, concrete requires reinforcing
and intricate forms, brick requires considerable skill to get a passable job, but wood
doesn't seem to care who works with it.
Wood is permanent and durable as long as it is kept dry. Wood frame houses two or
three hundred years old are not uncommon. But if moisture gets into wood, decay
starts and termites are attracted to it. Termites can be a real problem in the warmer
southern parts of the United States, but proper care in framing can keep their threat
to the minimum.
Photo owned by Flagstaffotos
Wood that comes in contact with foundations, or with concrete, brick, or other
surfaces that are inclined to be damp, or wood that is exposed to the weather
should be cedar, redwood, or cypress, or should be pressure-treated with chemicals.
In the western states the most commonly used framing lumber is Douglas fir. Pine,
hemlock, spruce, tamarack, cedar, and white fir are also used in limited quantities. Do
not use them for principal framing members. In the southern states long leaf yellow
pine is used as a strong framing lumber. Each section of the country seems to have
its favourites. Usually what the local lumber yard sells, if it also meets the demands
of the building inspector, will be satisfactory. Quality of workmanship is of equal
importance with the kind of material used.
Lumber contains many natural defects and acquires others in the process of milling
and distribution. The natural defects consist of knots, splits, wane, pitch seams,
decay, cross grain, worm holes, etc., and the acquired ones may be under size, warp,
twist, and most important, crookedness.
Small knots are not considered a defect in the construction grades, but large knots,
especially near the center of joists or rafters, do weaken the piece materially.
Although there is no need to worry about slight cracks or checks, a piece that is split
too far should have the split part spiked well together or should be cut off and used
for short pieces of some kind. A wane which is a place where the round part of the
tree subtracts a small corner of the timber is not usually serious. Discard any pieces
that show signs of decay or contain too many worm holes. Crooked pieces can
sometimes be straightened, especially where two are used together, by placing them
so the curvature of one tends to counteract the curvature of the other and spiking
By selecting the better pieces for the most important places, a really good frame can
be built, containing many pieces that are not of themselves first class. Be sure to use
plenty of nails, for the way building frames are often nailed, less than a fourth of the
actual strength of the timbers can be developed by the nails. The chapter on framing
will give instructions for nailing.
Although there are many grades of lumber, some of it graded for specific uses, the
home builder will be interested primarily in the grades commonly used in house
construction. The finish grades of Douglas fir are "B & Btr.," "C" and "D"; the framing
grades are now construction grade, standard, utility, and economy grades. Formerly
such terms as No. 1 common, No. 2 common, etc., were used and are still used in
The construction and standard grades should be used for most of the framing and
rafters, whereas the utility grade should be good enough for the studding, blocking,
short span joists, etc. Select the best ones to place beside the doors and windows,
and the straight ones for the corners. Many of the short pieces in the frame are
mostly something to nail to, and do not need to be of the best. You can usually buy
studding already cut to length, 8' or 7'-ll" long, and 2" x A" in dimension.
The local lumber dealer will know what grades are required by the local building
code, and what is ordinarily used in the vicinity. Do not try to economize too much
in the quality of the lumber you use. Of course, a few small knots are expected in
framing lumber; a large knot in the lower edge of a joist near the center of the span
is much more serious than one near the end of the joist. Where two or three
members are spiked together, a knot in one piece should do no harm. The members
in the frame of a house are not actually stressed anywhere near to the breaking
point; joists and rafters which are required to be of certain sizes so they will not sag
too much, are actually much stronger than they would otherwise need to be. See
table, page 113, for recommended spans of joists and rafters.
Exterior walls are often made of stucco, brick, concrete blocks, aluminum, shakes, as
well as wood siding.
Concrete is one of the most durable and strong building materials. The cost of the
concrete is low, but the forms to hold it in shape are usually expensive.
In places not subject to earthquakes walls of solid brick make an excellent building,
permanent and of pleasing appearance, requiring little or no upkeep.
Stucco wire in place fastened with furring nails. Wire is 11/2 water table above
boards where stucco begins. mesh, 17 gauge, galvanized stucco wire. Note
Building on a Slab
Building on a slab has a few advantages and several disadvantages. By building on a
slab is meant pouring a concrete slab over the area of the house, around which walls
are built and over which the roof is placed. The slab, with suitable floor coverings,
forms the floor of the house.
The advantages might be listed about as follows: it is more fireproof than other
methods of construction, as there is no space under the floor and the concrete is, of
course, fireproof. It is less expensive to build and quicker to construct. The floor is
quiet; the house can be built closer to the ground. The floors are not springy and
they do not squeak.
Photo owned by Yonela
Some of the disadvantages will be noted as we discuss the floor finishes, and others
will occur to the reader as he ponders the problem. The ants find it easier to get into
a slab house as it is closer to the ground. The water pipes are often concealed
beneath the floor, where it is impossible to service them. Heating problems are more
difficult with a slab floor. Termites are harder to control as the house is so close to
the ground. If you should ever have to move the house, it would be more difficult.
Although there are certain economies that result from building on a slab, a few
difficulties are also encountered.
The actual foundation costs about the same either way you do it, but it is less
expensive to pour a concrete slab than it is to frame a wood floor, both for material
and labour. If a person is capable of framing the floor, but would find pouring the
slab too much for him, the wood floor might be cheaper for him. Also the cost of
the two types of construction varies in different localities, so that in some places the
wood might actually be cheaper.
In pouring a concrete slab, care must be taken to make sure that moisture will not
come through the slab. Plastic sheets have lately been developed that when spread
over the entire surface under the concrete, quite effectively exclude moisture from
the floor. Sometimes a layer of gravel 4" thick is a great help in keeping the capillary
action from bringing moisture to the concrete slab. In cold sections of the country
perhaps it is best not to use the slab construction, at least unless special precautions
are taken to control the heat, cold, and moisture situation. Some kind of insulation
most certainly would be needed to keep the frost from coming in around the
outside walls, as concrete, which is a very good conductor of heat, will conduct heat
out of a house rapidly when the weather is cold.
While it is advisable to avoid slab floors in cold or wet districts, in warm dry climates
they seem to be quite successful. There are several finishes that should be
considered for concrete floors, several of which will be mentioned here. Asphalt tile
is the most widely used since it is not expensive, will stay in place in spite of
moisture, wears well, comes in many attractive colors, and requires a minimum of
upkeep. It does make a rather hard floor, which some people say is very tiring to the
feet when a person has to stand on it for long periods of time. Oils, fats, paste
waxes, and similar materials will soften and partially dissolve asphalt tile, which
makes it unsuitable for kitchen floors.
Although linoleum is a good floor covering, if the concrete is not properly
waterproofed the linoleum will not stay in place on it. Sometimes when linoleum
does not get moisture from below, it will condense it from the air. The concrete, a
good conductor of heat, when on cold ground will tend to be cold. Thus the warm
moisture-laden air deposits condensation on the cool surface of the linoleum;
enough moisture can collect to swell the linoleum and cause it to buckle. Note how
moisture collects on the outside of a glass of ice water.
Photo owned by Ruslan Vladimirovich Albitsky
It is almost impossible to cushion a floor on concrete successfully. Either it will be
too soft and spike heels will dent it, or it will not be soft enough to be satisfactory,
or the cushion will swell and buckle, or something seems always to be wrong with it.
There is, however, a new very thin cushion of sponge rubber that gives promise of
being successful, made especially to cushion linoleum.
Oak parquet blocks can be laid in waterproof mastic on a concrete floor with good
effect and very few problems.
Vinyl asbestos tile seems to do fairly well on a concrete floor.
Burned tile, quarry tile, ceramic tile, etc., are ideal over concrete for bathrooms,
hallways, laundry rooms, patios, porches, etc.
Carpet can be put on a concrete slab very successfully. After the concrete is
thoroughly water-proofed, or even if not quite so well done, a good hair felt or
rubberized pad is put on the concrete. A rug is then stretched over this to make a
very satisfactory floor, warm, resilient, and comfortable.
Here is a suggestion for floor finishes in a house built on a slab: slate floors on the
porches and in the entrance hall; ceramic tile in the back hall, in the laundry, in the
bathrooms and on the patio; oak parquet floors in the dining room and in the den;
cushioned linoleum in the kitchen; wall-to-wall carpet in the living room; asphalt tile,
vinyl asbestos tile, oak parquet blocks, or wall-to-wall carpet in the bedrooms.
Incidentally, most of the tract houses I have seen lately are using asphalt tile floors
almost exclusively; once in awhile you find a kitchen floor of vinyl tile. Some of the
tract houses leave the concrete exposed in the living room with the idea that the
owner will use carpet on the floor.
Advantages of Building on a Wood Frame Floor
If you use a wood frame under the floor, it is more resilient and easier on the feet,
inclined to be warmer, and it is easier to install satisfactory finish floors and floor
coverings. You can get under to service or repair the plumbing. The house could be
moved if necessary. The first item is often the deciding factor, as the resilient floor is
so much easier on your feet and is not so much inclined to be cold.
The disadvantages may be that the floor is not fireproof, that it is slightly more
expensive to build, that it takes more time and work, and if the space under the floor
is not properly ventilated, the joists and floor may be damaged by so-called dry rot
or by termites.
The average beginning builder is perhaps better off not to undertake building on a
slab unless he is willing to investigate the local conditions carefully and study every
problem in connection with it, as it has many pitfalls.
Since concrete is a good conductor of heat, in a very cold country the heat is liable
to escape around the outside walls, causing frost to form on the floor just inside the
walls. This might be partly overcome by properly placed insulation, but insulation in
this position could easily become damp and thus ineffective. In places where many
people are building satisfactory houses on slabs, go ahead and follow, but
pioneering in a new place where conditions are different could be hazardous. Soil,
moisture, temperature, the kind of concrete, and the climate all have such a bearing
that it is often wise to let others do the expensive experimenting involved in building
a new kind of house. A house is too expensive a proposition for the average person
to use in experimenting with novel ways of doing things. This is not to say that many
of our building methods could not well be improved, but to suggest that we let the
experimenting be done by those who can afford to do it.
Another thing that must be remembered is that the local building codes often have
not caught up with some of the newer methods, and the loan companies are even
more conservative, when it comes to something out of the ordinary or different from
that which they are accustomed to seeing done.
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