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
FRAMING
This is a subject on which volumes have been written. The general arrangement with the names and sizes of the various members is shown in the drawing, a design for a small cottage, or bungalow. ([Fig. 227].)
The heavy timbers forming the sill are cut to the outside dimensions of foundation and halved at the corners. Fasten the joints with ten or twelve penny nails. Cut all corner posts exactly the same length, toenail at corners to sill, and hold in position by temporary braces. Plumb the posts as the braces are nailed. Two boys must work at this job, one holding the plumb and the other nailing the braces. Cut and halve the ends of plate the same length as sill, and nail to corner posts. Cut 2 × 4 studs same length as posts, then nail to sill and plate 16 inches apart on centres. The openings to be left for doors and windows will break up the even spacing of the studs, but it should be made as uniform as possible. The spaces for door and window frames are to be enclosed with double studs to give the necessary strength. Corner braces are very desirable and in the old-fashioned braced frame were mortised into plate and post, and sill and post. ([Fig. 227a].)