Foundations; Footings. Because of the tendency of a building to settle unevenly, due to variations in the strength of the supporting ground or the unequal weight placed upon this ground, foundations must be constructed of some non-yielding material such as brick or stone, and of such thickness and so bonded that the weight of the building may be evenly distributed.
The thickness of wall will depend upon the weight to be supported and upon the character of the soil.
Unless rock or gravel is encountered, every foundation should have a footing, Fig. 7. The amount of footing used is usually twice the thickness of the foundation wall. In brick walls this footing draws into the wall by "stepped" courses of brick, each layer being narrower than the one just preceding. For ordinary residence work with ordinary soil conditions a 10- or 12-inch wall resting upon a footing 2 feet wide and 8 or 10 inches deep will suffice.
Fig. 7. Foundation Detail.
A safe footing for supporting posts of 6" x 6" yellow pine, for most soils, will be 10 inches deep by 18 inches square. Partition walls carrying no unusual load need not be over 8 inches in thickness.
Fig. 8. American Bond.
In many communities the use of concrete is supplanting that of stone or brick, especially below the grade line. Such a wall should be composed of 5 parts of crushed stone or gravel, 3 parts sand, and 1 part cement. The footing may be formed by tamping
Plan Of Course 1.
Fig. 9. English Bond.
the mixture in a form made by spading out of the earth a depth and width sufficient for the wall to be supported.