SECTION 748:20-5-8. IRC® 2015 Chapter 5 Floors

  Chapter 5 of the IRC® 2015 is adopted with the following modifications:

(1)   Section R506.2.1 Fill. This section has been modified to provide fill lift measurements and delete a requirement for the slab and stem wall system to be designed by accepted engineering practice/standards by a design professional. This section has been modified to read: R506.2.1 Fill. Fill material shall be free of vegetation and foreign material. The fill shall be compacted in 8 to 12 inch (203 mm to 305 mm) lifts to ensure uniform support of the slab, and except where approved, the fill depths shall not exceed 48 inches (1220 mm) for clean sand or gravel and 8 inches (203 mm) for earth.

(2)   Section R506.2.3 Vapor retarder. This section has been modified to allow for other industry accepted vapor retarders installed according to the manufacturer's specifications. This section has been modified to read: R506.2.3 Vapor retarder. A 6 mil (0.006 inch; 152 micrometers) polyethylene sheeting, other industry accepted vapor retarder products installed per manufacturer specifications or approved vapor retarder with joints lapped not less than 6 inches (152 mm) shall be placed between the concrete floor slab and the base course or the prepared subgrade where no base course exists. Exception: The vapor retarder is not required for the following:

(A)   Garages, utility buildings and other unheated accessory structures.

(B)   For unheated storage rooms having an area less than 70 square feet (6.5 square meters) and carports.

(C)   Driveways, walks, patios and other flatwork not likely to be enclosed and heated at a later date.

(D)   Where approved by the building official, based on local site conditions.

[Source: Added at 28 Ok Reg 2122, eff 7-15-11; Amended at 33 Ok Reg 1852, eff 11-1-16]