Construction types

Light noncombustible (ISO Class 3, IBC Type IIB)

Light Noncombustible construction is ISO Class 3. ISO Class 3 encompasses IBC Type IIB (unprotected).

Light Non Combustible buildings are buildings with exterior walls of light metal or other Noncombustible material and with Noncombustible floors and roofs:

buildings with exterior walls, floors, and roofs of noncombustible or slow-burning materials
building supports of noncombustible or slow-burning materials
noncombustible or slow-burning roof decks on noncombustible or slow-burning supports ó regardless of the type of insulation on the roof surface

noncombustible advantages:

easy to erect
economical to build
uses materials that donít readily burn

noncombustible disadvantages:

contains steel, which looses strength at high temperatures
highly damageable buildings
unstable buildings under fire conditions
uses slow-burning materials that do burn ó adding fuel to a fire 

Masonry Noncombustible (ISO Class 4, IBC Type IIA)