Ridge Beam Roof Design

The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial.

Ridge beam roof design.

Design of single span ridge beams in roofs in houses office buidlings schools and other structures. The ridge beam could also be flush with the joists 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. 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.

However for low to moderate roof slopes the ridge beam must also be designed to resist upward force from wind uplift pressure on roof surfaces. Continuing on from part 3. For downward gravity loads design of a structural ridge beam is similar to any other beam see basic beam design. 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.

Floor beam span tables of residential structural design we will now look at roof rafter and beam design. A ridge beam is a structural member used to support the ends of the rafters at the ridge transferring it s loads to posts or gable end walls. Rafters on each side of the ridge beam are considered to be simply supported beams. Ridge beam single span.

A classic example of the exposed ridge beam structure can be seen on our magnolia. I can t ever recall seeing a saltbox shed built with a ridge beam or even a gambrel roof shed for that matter. The sloped roof joists span between two pinned points. Let s consider a basic gable wood roof framing design.

Definition of structural ridge or ridge beam used in roof framing. Distance from roof beam to next roof support i e the span of the rafter or roof truss from the roof beam to the next adjacent beam or wall. One at the envelope of the structure on top of a framed wall or a header the other at the peak of the structure on top of the ridge beam. Determining the ridge beam height if you know the slope x in 12 you want to use for your roof framing design you can use it along with the run r to determine the height of the ridge beam.

Ridge beams are required by code if the roof slope is less than 3 in 12 irc section r802 3. Leave ridge beam for shed construction page. For example if the slope is 4 in 12 and the run is 12 feet the ridge beam height m will be 4 feet.