Roof Ridge Beam Sizing

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.

Roof ridge beam sizing.

Timber steel framing manual single span ridge beam. Most interior beams need to include the roof load. Ridge beam sizing is based on the span of the beam between supports and the amount of roof load supported by the beam. Once the ridge beam has been positioned in place and supported by roof framing members you can determine the placement of a rafter by measuring down from the top of the beam y height and making a mark on the beam.

Fv does not change when you double the thickness. Ridge boards can only be used in roofs with slopes from 3 in 12 up to 12 in 12. A ridge board is a non structural member that serves as a prop for opposing rafters to rest against and connect to. Ridge beam height above top of slab height of wall z.

Rafter to ridge beam connection framing roof ceiling construction structural ridge beam absolute deflection in a ridge beam structural ridge beam tricks of the trade. Also see assumptions for table development. For each application a pdf download is available. Loading conditions are detailed below.

It has been my experience to never use a beam smaller than a two ply 2 x 8. For l 180 multiply by 0 5. The formula for determining the finished height of the ridge beam from the top of the slab to the top of the ridge beam is. Sizing ered beam archives load bearing wall removal.

Make sure the shear value fv for the species and grade you use exceeds the fv listed in the span table. If you size a roof beam like a structural ridge that has a l 240 limitation you would multiply the minimum e value by 0 666 785 000 x 0 666 522 810 in this case. Refer to sfpa s publication southern pine headers beams download in publications that includes all size selection and allowable load tables.