VARIETIES OF TIMBER Although there are a great many different kinds of trees growing in different parts of the world, only a comparatively small number of them yield wood which is used to any great extent in building work. These differ very much among themselves, each variety possessing certain characteristics which render it especially suitable for use in one part of a building, while the same peculiarities of growth or of texture may make it unfit for use in another.
For use in places where the timber must be partly buried in the ground a wood is required which will be able to withstand the deteriorating effects of contact with the earth, and for this purpose chestnut, white cedar, cypress, redwood, or locust may be used.
For light framing is needed a cheap, light wood, as free as possible from structural defects, such as knots and shakes, and one which can be readily obtained in fairly long, straight pieces. Spruce, yellow pine, white pine, and hemlock all satisfy these requirements fairly well, spruce being perhaps a little better than the others, and more popular.
For heavy framing, such as trusses, girders, and posts, a timber is needed which is strong, and which can be obtained in large, long pieces. Georgia pine, Oregon pine, and white oak may all be used for such wo=rk, and also Norway pine and Canadian red pine. White oak is the timber which was always used for framing in the old days, but is too expensive to be used with profit for such work now. The timber most commonly used today is the Georgia pine.
A wood which can be easily worked and which will also be able to withstand the deteriorating effects of the weather is in demand for the outside finish. White pine is usually selected for this purpose, although cypress and redwood are also suitable and are used to some extent. The same woods are used for shingles, clapboards, and siding, with the addition of cedar and spruce for shingles, and Oregon pine and spruce for siding.
FOr the interior finish is chosen a wood which will give a pleasing appearance when finished and which will take a high polish, while for floors, hardness, and resistance to wear are the additional require ments. For floors, oak, hard pine, maple, and birch are good, while for the remainder of the interior finish white pine, cypress, and red wood for painting, or any of the hard woods such as ash, cherry, oak, walnut, or mahogany, may be selected.
Some of the more important varieties of timber used in Car pentry will now be mentioned, and a brief description of each variety will he given in order to convey an idea of their characteristics and the part of the world from which they come.
Conifers or Needle-Leaved Trees. These trees are found mostly in the North, where they form large forests from which are taken the large quantities of timber of this kind used every year. The wood is very popular for use in rough building construction or for finished work which is to be painted, as it is very regular in structure and consequently easy to work; it can be obtained in large, long, straight pieces, and is light and strong. The demand for woods of this kind is considerably in excess of the demand for the harder woods. The trees are mostly but not all evergreen, and bear needles instead of leaves, together with the cones, from which they arc called conifers.
Cedar. The wood known as cedar has long been used in con struction, as is illustrated by the references in the Bible to the "Cedars of Lebanon" from which the Temple of Solomon was constructed. The wood in use at the present day called cedar is, of course, not of exactly the same species as was that used in the famous temple, but it is of the same family and possesses the same general character istics. There are two kinds, the red cedar, and the white cedar, which differ from each other principally in color, the white cedar being grayish brown, while the red cedar is reddish brown.
There are several different kinds of white cedar in use, of which one is known as the canoe cedar. The wood is not very strong, hut is light and soft, possessing considerable stiffness and a fine texture. In color it is as mentioned above, grayish brown, the sapwood being, however, of a lighter color than the heartwood. It seasons quickly, is remarkably durable, and does not shrink or check to any great extent. The wood is used in building construction, principally for shingles, for which purpose its durability in exposed positions makes it especially valuable. It is also used for posts and ties.