Section 1809 of the 2020 Florida Building Code, Building, 7th Edition requires shallow foundations to be placed 12-inches below the undisturbed ground surface and requires a 12-inch minimum foundation width. The relevant section states:
1809.4 Depth and width of footings. The minimum depth of footings below the undisturbed ground surface shall be 12 inches (305 mm). Where applicable, the requirements of Section 1809.5 shall also be satisfied. The minimum width of footings shall be 12 inches (305 mm).
Foundations that do not meet this building code requirement could suffer from settlement related damage. The Florida Building Code defines a “shallow foundation” as “…an individual or strip footing, a mat foundation, a slab-on-grade foundation or a similar foundation element.”
For building code questions or assistance with evaluating foundations or settlement related damage to a building or other structure, please contact Burby Engineering at firstname.lastname@example.org.