Roof Ridge Beam Construction

A timber frame roof has rafters and a ridge beam as with stick framing but the ridge is a large structural beam that the rafters sit on top of or sometimes fit into notches cut into the beam.

Roof ridge beam construction.

The ridge board runs the length of the building and provides support for the tops of the rafters helping the whole roof structure work together as a system. I can t ever recall seeing a saltbox shed built with a ridge beam or even a gambrel roof shed for that matter. Timber framing is a traditional method of framing that uses heavy timbers instead of standard board lumber. The loads on the ridge beam are carried by vertical posts at the beam ends down through the building structural walls to the building foundation.

Because a ridge beam often carries a significant area of roof load they can exhibit structural distress due to a defect in wood impact on the roof or use of an undersize beam. A simple rafter roof consists of rafters that the rafter foot rest on horizontal wall plates on top of each wall. The ridge beam is typically a larger member like a 4 x 12 and carries the gravity load of the roof joists just as the bearing wall or header does at the envelope. Ridge beam sizing is based on the span of the beam between supports and the amount of roof load supported by the beam.

B a ridge beam supported by not less than 89 mm length of bearing. The ridge beam shown below at the living room of a 1950s modern style ranch house in gainesville has cracked at mid span and is slowly heading towards failure after the crack opened further after a recent repair. A ridge board is a non structural member that serves as a prop for opposing rafters to rest against and connect to. A classic example of the exposed ridge beam structure can be seen on our magnolia residence which is currently in construction.

The ridge board must be set as perfectly as possible so take your time and use careful measurements. The top ends of the rafters often meet at a ridge beam but may butt directly to another rafter to form a pair of rafters called a couple. Come to think of it the only style shed i can see that would be easy to use a ridge beam is the gable style shed. 2 except as provided in sentence 3 the ridge beam referred to in sentence 1 shall conform to the sizes and spans shown in table a 12 provided a the supported rafter or joist length does not exceed 4 9 m and b the roof does not support any concentrated loads.

Ridge beams are required by code if the roof slope is less than 3 in 12 irc section r802 3. Construction of a rafter roof. Timber frame ridge beams.