Roof Ridge Board Size

Is 22 ridge board too long of a span worried about roof sag.

Roof ridge board size.

Some say i can use my 9 1 2 i beams for rafters and a single 2 x12 ridge board across the 16 span at the ridge. The ridge board s length will be the outside measurement of the building plus the length of the overhang at both ends. Outside of the u s a degree angle is typically used. In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches.

A ridge board is a non structural member that serves as a prop for opposing rafters to rest against and connect to. Ridge boards shall be at least 1 inch nominal thickness and not less in depth than the cut end of the rafter irc section r802 3. Others are saying i need an lvl ridge beam. For 2 x 4 rafters use a 2 x 6 ridge board.

For 2 x 6 rafters use a 2 x 8 ridge board and so on. Choose a ridge board that is one size larger than your common rafters. For instance a 7 12 roof pitch means that the roof rises 7 inches for every 12 horizontal inches. I have read that a ridge board beam when used with wood i joists for rafters should have a ridge board beam that can support the entire roof load since the i beams are not designed to tolerate the compression that can occur in my situation.

Ridge boards can only be used in roofs with slopes from 3 in 12 up to 12 in 12. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.