Garden Wall Specifications 2
In a concrete or masonry wall, the batter or slope made necessary by the weight which the wall supports must be accurately figured. For walls up to 20 feet high this is an easy matter. First lay off the height of the wall from the top to bottom of footing. Four to five tenths of this distance is the required thickness of the wall at the base. The thickness at the top of the wall should not be less than 18 inches. The slope may be on either the inside or the outside of the wall, or both. A slope of one to twelve on the outside looks well and the inside, which does not show, can be sloped as much as is necessary to give the right thickness at the bottom. Of course if the wall is so low that four tenths of the height is less than the minimum thickness of the wall there will be no batter. Eighth. In any retaining wall weep holes must be provided at a point about 8 inches above the grade on the lower side. They should be about 12 feet apart along the entire length of the wall. They serve to carry through whatever moisture may collect along the inner face where it might so soften the soil and undermine the footings that the wall would slide forward on its foundations. It is often necessary, especially in clay soils, to provide a line of porous tile behind the wall to collect and carry off excess moisture. This is placed at the level of the footing, and outlets should be provided at the ends or through and under the wall.