1 Hour Roof Over Hang Protection

The ibc in section 705 2 3 permits the use of type iv construction fire retardant treated wood or 1 hr fire resistance construction for combustible projections.

1 hour roof over hang protection. Roof overhangs must have a one hour fire protection on the underside when less than 5 from the property line and cannot project closer than 2 from the line. The ibc provides options while the irc has only one method of compliance. To the closest interior lot line. To the centerline of a street an alley or public way.

The irc in table r302 1 1 only. Overhangs can be open in which the trusses rafters and decking are exposed see figure 1 or enclosed by a soffit. For complete information on the listed systems the actual listing or test report should be reviewed. Wall framing whichever is closer to one of the following.

Roof ceiling and attic separation. Use flat horizontal soffits see figure 3 instead of attaching the soffits to the sloped joists which creates sloped soffits. Walls less than 5 feet from the property lot line must be of a listed hour fire1 resistant construction. Overhangs such as roof eaves and soffits are one element needing protection.

Enclose overhangs with soffits that have a minimum 1 hour fire resistance rating to prevent embers and hot gases from making contact with the joists rafters or trusses or the underside of the roof decking. Soffits a soffit encloses the underside of sloped or flat roof overhangs. However a garage located within 2 of the property line is permitted to have a 4 inch roof eave projection. To an imaginary line between two buildings on the lot.

Ibc section 703 3 item 2.