The International Residential Code For One- and Two-Family Dwellings provides regulations
for the construction of single-family houses, two-family houses, and buildings consisting
of three or more townhouse units up to three stories high.
IRC Chapter 9, "Roof Assemblies," contains a majority of roofing-related code requirements.
Chapter 8, "Roof-Ceiling Construction," provides attic ventilation requirements.
Minimum thermal insulation requirements for ceilings are provided in IRC Chapter
11, "Energy Efficiency." The design and installation of ceiling insulation is not
typically part of a roofing contractor's scope of work.
According to the International Code Council (ICC), the developer and publisher of
IRC, state and local jurisdictions in 49 states; the District of Columbia; and the
U.S. Virgin Islands use one of several versions of IRC as the technical basis for
their adopted building codes.