How To Grade A Foundation Floor

A raised floor is also used to raise the building above a floodplain.

How to grade a foundation floor.

Generally it is the siding that should be above the grade not the finished floor. The major structural components of a slab on grade foundation are the floor slab itself and either grade beams or foundation walls with footings at the perimeter of the slab see figures 4 2 and 4 3. 2009 concrete and masonry foundation walls shall extend above the finished grade adjacent to the foundation at all points a minimum of 4 inches 102 mm where masonry veneer is used and a minimum of 6 inches 152 mm. Concrete masonry is used to construct various foundation wall types including full basement walls crawlspace walls stem walls and piers.

The foundation insulation is in the same plane and is applied to the slab edge below the termite shield down to the footing. Concrete masonry is well suited for below grade applications because of its strength durability economy and resistance to fire insects and noise. A good builder determines the highest point of ground near the home and sets the top of the foundation in relation to this high point. The foundation wall may be an integral part of the load bearing design of the building carrying column and floor loads from above either as distributed loads on the wall or point loads on pilasters integral to the wall system.

A raised floor foundation has many pros and fits most project applications. In some cases additional footings often a thickened slab are necessary under bearing walls or columns in the center of the slab. The word grade references the level of all the ground on your building lot before you start to dig a hole for the foundation. The slope of the finished grade must be maintained at a minimum of 6 inches of fall within 10 feet.

If the building site has problematic soil such as expansive clays a raised floor foundation would perform much better than slab as slab would most likely crack on this type of soil. The grade beam sits on a footing which provides support for the brick cladding. And drainage elements to the exterior of below grade foundation walls a slip plane should be introduced. Foam insulation runs on the inside face of the airspace behind the brick.

Figure 4 15 illustrates a slab on grade with an integral grade beam.