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.

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. Builders need to be sensitive to these established grades. Concrete masonry is well suited for below grade applications because of its strength durability economy and resistance to fire insects and noise. 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.

And drainage elements to the exterior of below grade foundation walls a slip plane should be introduced. And also make sure the grade falls away from the foundation to be specific the 2015 international residential code irc requires the foundation to be 4 inches above the finished grade when covered by a masonry veneer or 6 inches elsewhere. 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 foundation insulation is in the same plane and is applied to the slab edge below the termite shield down to the footing.

Generally it is the siding that should be above the grade not the finished floor. A raised floor foundation has many pros and fits most project applications. The slope of the finished grade must be maintained at a minimum of 6 inches of fall within 10 feet. 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.

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. R404 1 6 height above finished grade. 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.

In some cases additional footings often a thickened slab are necessary under bearing walls or columns in the center of the slab.