Attic Draftstopping Details

Some codes include other draftstopping materials such as gypsum board cement fiber board or particleboard.

Attic draftstopping details. O draftstopping must be installed to subdivide concealed combustible attic spaces into areas not exceeding 3 000 sq ft draftstopping materials must comply with the following. Must extend to the underside of the roof sheathing draftstopping materials must not be less than o 0 5 inch gypsum board o 0 375 inch wood structural panel. Draftstopping is used to subdivide flooring at specific intervals and in attics and crawl spaces. This self closing and self latching access door allows for access from both sides of the door.

There are some points to be made about the draftstoppingrequirements. 3 if draftstoppingis required the 1 000 sflimit applies but the divided spaces must be approximately equal. Similar to fireblocking draftstopping is installed to prevent the movement of air within open building areas and is most often installed in crawl spaces attics and floor assemblies. In combustible construction nearly all the codes specify that lumber or wood structural panels may be used for this purpose.

Group r 2 occupancies not exceeding four stories in height must have combustible attic draftstopping every 3 000 square feet or above every two units whichever area is smaller. Multi family buildings generally require draftstopping in line with the dwelling units and tenant separations. 1 if there is no useable space above the assembly an attic or below it a crawlspace draftstoppingisn t required. Multi unit housing projects are often draftstopped at specific intervals to prevent fire from jumping between adjacent units via a common attic space.

Draftstopping shall be provided in attics mansards overhangs or other concealed roof spaces of group r 2 buildings with three or more dwelling units and in all group r 1 buildings. Draftstopping shall be installed above and in line with sleeping unit and dwelling unit separation walls that do not extend to the underside of the roof sheathing above. Draftstopping is usually provided by requiring a plywood or gypsum board barrier at 3 000 ft sq intervals in attic spaces. 2 if the assembly isn t concealed an open floor ceiling assembly above a basement draftstoppingisn t required.

Ceiling is suspended under the floor framing. A horizontal area of 1 000 ft sq between draftstops is a typical requirement in non residential buildings in floors.