Draftstopping Partition Attic Detail

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 partition attic detail.

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. Some codes include other draftstopping materials such as gypsum board cement fiber board or particleboard. Draftstopping in floor ceiling spaces and attic spaces shall comply with sections 718 3 and 718 4 respectively. Draftstopping 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. Fireblocking shall be provided in concealed spaces of stud walls and partitions including furred spaces and parallel rows of studs or staggered studs as follows. Vertically at the ceiling and floor levels. Multi unit housing projects are often draftstopped at specific intervals to prevent fire from jumping between adjacent units via a common attic space.

Openings through these partitions whall be protected by self closing doors of the same thickness and materials as the partition. If a fire rated assembly rather than draftstopping is required within concealed attic spaces the following details show approved one hour and two hour rated assemblies that may be used in the roof cavity and that may be constructed with gable end frames or trusses. Draftstopping materials shall not be less than 1 2 inch 12 7 mm gypsum board 3 8 inch 9 5 mm wood structural panel 3 8 inch 9 5 mm type 2 m particleboard or other approved materials adequately supported. 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.

Draftstopping is used to subdivide flooring at specific intervals and in attics and crawl spaces. Where the attic is fully equipped with an automatic fire extinguishing system the divided horizontal area may be tripled. Openings in the partitions shall be protected by self closing doors with automatic latches constructed as required for the partitions. 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.