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.
Attic draftstopping details.
Where the assembly is enclosed by a floor membrane above and a ceiling membrane below draftstopping shall be provided in floor ceiling assemblies under the following circumstances.
A horizontal area of 1 000 ft sq between draftstops is a typical requirement in non residential buildings in floors.
Draftstopping is used to subdivide flooring at specific intervals and in attics and crawl spaces.
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.
Multi unit housing projects are often draftstopped at specific intervals to prevent fire from jumping between adjacent units via a common attic space.
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.
In combustible construction nearly all the codes specify that lumber or wood structural panels may be used for this purpose.
This self closing and self latching access door allows for access from both sides of the door.
Some codes include other draftstopping materials such as gypsum board cement fiber board or particleboard.
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.
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.
The babcock davis draft stop door is a non rated access door designed to provide access through draft stop spaces in the attic while preventing a back draft from one section of the attic to another.
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.
3 if draftstoppingis required the 1 000 sflimit applies but the divided spaces must be approximately equal.
There are some points to be made about the draftstoppingrequirements.
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 shall divide the concealed space into approximately equal areas.
