1 Hour Roof Over Hang 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.

1 hour roof over hang protection.

An overhang protects the upper portion of the wall that it is attached to from rainfall and it also shades the windows under it from the sun. To the closest interior lot line. 1 hour rated wall and protected eave overhang soffit board 1 2 cdx ply 2 x 4 block 2x framing 5 8 type x gypsum sheathing siding 5 8 type x gypsum wallboard structural sheathing as required fascia approved roof covering alternate location of gwb or 2x blocking if no ceiling finish is provided 1900 sw 4th avenue suite 5000 portland or 97201. For complete information on the listed systems the actual listing or test report should be reviewed.

However a garage located within 2 of the property line is permitted to have a 4 inch roof eave projection. The irc in table r302 1 1 only. Wall framing whichever is closer to one of the following. Eave overhang fire protection.

Walls less than 5 feet from the property lot line must be of a listed hour fire1 resistant construction. 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. See attached image we are hoping to replicate this in the addition.

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. Prescriptive designs ibc table 721 3 item 21 1 1 describes a single prescriptive 1 hour rated floor or roof assembly that includes wood trusses. Soffits a soffit encloses the underside of sloped or flat roof overhangs. Overhangs such as roof eaves and soffits are one element needing protection.

The existing open eaves have t g sheathing with exposed rafter tails and 2x blocking b w rafters. Use flat horizontal soffits see figure 3 instead of attaching the soffits to the sloped joists which creates sloped soffits. Overhangs can be open in which the trusses rafters and decking are exposed see figure 1 or enclosed by a soffit. Ibc section 703 3 item 2.

Roof ceiling and attic separation. To an imaginary line between two buildings on the lot.