Fire Resistive, Modified Fire Resistive and Masonry Noncombustible.

Fire Resistive: Buildings where the exterior walls, floors and roof are of masonry or other fire resistive materials with a fire resistive rating of not less than two hours.

Modified Fire Resistive: Buildings where the exterior walls, floors and roof are masonry or other fire resistive materials with a fire resistive rating of not less than one hour.

Masonry Noncombustible: Buildings where the exterior walls are of brick, concrete, gypsum block, hollow or solid concrete block, stone, tile or similar materials, with floors and roof of unprotected metal or other noncombustible materials.

Joisted Masonry and Noncombustible
Joisted Masonry: Buildings where the exterior walls are of masonry materials such as brick, concrete, gypsum block, hollow or solid concrete block, stone, tile or similar materials, with floors and roof of wood or other combustible materials.

Noncombustible: Buildings employing a system of prefabricated steel framing members. The roof is usually constructed of metal panels and the exterior walls of metal siding, sandwich panels or masonry materials. Light noncombustible construction is sometimes referred to as pre-engineered.