FOUNDATIONS
These, like all details, depend on the size and purpose of the building. The method of setting a small building on posts has been explained under poultry house, and sheltered seat for tennis court. It should be used only for small structures, such as camp buildings, sea-shore cottages, and out-buildings. Brick, stone, and concrete all have their advantages, but for young builders, concrete is perhaps the best and easiest to handle. The woodwork necessary for concrete work is extremely important, and its possibilities have hardly been touched, even to-day. The box or form should present the smooth side of the boards to the concrete, and should be so constructed that the form may be readily removed after the concrete has hardened. This sounds like a simple matter, but it becomes complicated in many cases. The method of fastening the wooden frame to a concrete foundation is suggested in the chapter on the making of a pergola. In some houses the frame is simply laid on the concrete, and the weight of the building is trusted to keep it in place.
In the case of small structures this would not be sufficient, and a better way would be to imbed bolts in the cement before it hardens. Pass these bolts through holes bored in the sill, and fasten them with nut and washer on top, after the concrete has hardened.
Any foundation should be sunk at least three feet in the ground, otherwise it will be "heaved" by the frost. Where a cellar is to be built, the foundation should be of sufficient depth to leave at least 6 feet 6 inches in the clear between floor of cellar and under side of floor beams, and seven feet would be better. If the foundation extends two feet above the ground, its bottom would be 5 feet 6 inches below the ground level.
The thickness of the concrete wall must depend on the size and weight of the building, and for a small cottage it should not be less than ten inches. The columns described for the pergola make an excellent foundation for a small building to be placed on posts, as they do not decay and are permanent. They may be used to advantage for porches in place of wooden posts.
After a building is completed, some of the top soil removed in digging the cellar should be graded up to the foundation at a slight slope, to shed the rain and carry it away from the building. The box for a concrete wall should be well supported and braced, as the weight is sufficient to force the boards out of position. The method shown at [Fig. 226] is frequently used, the 7⁄8 or 1 inch plank being supported by 2 × 4 inch studs, which in turn are braced as shown. On cheap work the outside boarding is omitted, the earth being shaved with the shovel as near the position of outer casing as possible. Of course, this earth wall is only useful within a foot or so from the surface. At this point the outer boarding must commence, and be continued to top of foundation. In order to have the foundation level on top, it is best to level the wooden form all around the four sides. If the concrete is brought exactly to the top, and a straight edge is run along the edges of the form, the resulting wall must be level, provided the box has been made so. Concrete does not flow enough to level itself.
Fig. 226. Concrete foundations