As seen in The Washington Post, this Ask the Builder article by Tim Carter reinforces the information that has been presented for years by the Concrete Foundations Association.

Carter provides sound advice: “keep the foundation well above grade. 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 slope of the finished grade must be maintained at a minimum of 6 inches of fall within 10 feet.

This residential structure with masonry cladding has landscaping and finished grade (around front) extending up onto the brick and above the height of the wood sill plate indicated by the orange line at the first exposed mortar joint.

According to Carter, building codes from “not too long ago” require a minimum of least six inches of foundation showing above the soil grade, and at least six inches of fall in the soil in the first ten feet away from the house. Carter recommends building a foundation at least 18 inches higher than the surrounding soil, and using dirt dug from the basement to make a “long gentle slope” away from the foundation.

Read the complete article on the Washington Post website or contact CFA executive director, James Baty, for more information on the position of foundation heights and grade slopes as they relate to the ACI/CFA Residential Foundation Technician Certification.