Do codes allow rigid insulation to be used on walls or ceilings in a house?
A Building codes require that foam insulation exposed to the interior of a building must be covered by a non-flammable surface, such as 1/2-inch drywall. In some cases, such as when rigid foam insulation is used as part of a roof assembly, codes might allow it to be covered with plywood sheathing. However, always check with your local building inspector to determine the most suitable installation details for rigid foam insulation. For more information on insulation, see Chapter 39 of Glencoe’s Carpentry & Building Construction 2005, by Mark Feirer.
