Attic Draftstopping Detail

There are some points to be made about the draftstoppingrequirements.

Attic draftstopping detail.

This self closing and self latching access door allows for access from both sides of the door. O draftstopping must be installed to subdivide concealed combustible attic spaces into areas not exceeding 3 000 sq ft or above every two dwelling units whichever is smaller where a corridor also serves as a dwelling unit separation draftstopping is only required above one of the corridor walls. In combustible construction draftstopping shall be installed to subdivide attic spaces and concealed roof spaces in the locations prescribed in sections 718 4 2 and 718 4 3. 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. Some codes include other draftstopping materials such as gypsum board cement fiber board or particleboard. If the assembly isn t concealed an open floor ceiling assembly above a basement draftstopping isn t required. 1 if there is no useable space above the assembly an attic or below it a crawlspace draftstoppingisn t required.

718 4 draftstopping in attics. Draftstopping is used to subdivide flooring at specific intervals and in attics and crawl spaces. A horizontal area of 1 000 ft sq between draftstops is a typical requirement in non residential buildings in floors. 3 if draftstoppingis required the 1 000 sflimit applies but the divided spaces must be approximately equal.

In combustible construction draftstopping shall be installed to subdivide attic spaces and concealed roof spaces in the locations prescribed in sections 718 4 2 and 718 4 3. Draftstopping shall divide the concealed space into approximately equal areas. In combustible construction nearly all the codes specify that lumber or wood structural panels may be used for this purpose. Group r 1 o required in all buildings.

Ventilation of concealed roof spaces shall be maintained in accordance with section 1203 2. 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. If draftstopping is required the 1 000 sf limit applies but the divided spaces must be approximately. 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.

Ceiling is suspended under the floor framing. The space between the ceiling beams of the top story and the roof rafters.