R316.4

Section R316.4 is titled 'Thermal barrier' and covers the requirements for allowing foam plastic insulation with a thermal barrier installed between it and the inside of the dwelling. The minimum thickness of certain specific types of thermal barriers, and a testing method and standard to determine allowance of other types of materials used as thermal barriers is established. The purpose of this section is to slow the spread of fire. The Building Official will need to approve the method for fastening the thermal barrier to the adjacent building construction.

The model shows a section of a basement wall with foam plastic being used as interior insulation between hat channel framing members, with 1/2" gypsum board thermal barrier being installed over the face of the foam plastic. Not shown in the model is the thermal barrier being placed over the top side edge of the foam plastic.