ICC Commercial Building Inspector Practice Test

Which material is suitable for use as draftstopping?

1. 1/2 inch gypsum board

2. 3/8 inch plywood

3. OSB board

4. 2x4 lumber

The correct answer is: 3/8 inch plywood

The suitable material for use as draftstopping is 1/2 inch gypsum board. Draftstopping is an essential component in managing smoke and fire spread within building cavities, especially in commercial settings. Gypsum board is commonly accepted for this application due to its inherent fire-resistant properties and structural integrity. Gypsum board is specifically designed for use in areas like ceilings and between walls where there is a need to limit the movement of smoke and heat in the event of a fire, thereby enhancing the building's overall safety. It meets regulatory requirements set forth in building codes pertaining to draftstopping, making it a reliable choice for this purpose. While plywood, OSB board, and lumber have their uses in construction, they do not provide the same fire-resistant characteristics that gypsum board does and may not effectively contain smoke or fire as per code requirements. This makes gypsum board the standard material for draftstopping in commercial buildings.