Ridge Beam Sizing Table

Refer to sfpas publication southern pine headers beams download in publications that includes all size selection and allowable load tables.

Ridge beam sizing table. Live load overhang kpa. On longer spans the beam may require much more bearing space as indicated by this table. Loads are calculated in accordance with table 31 of asnzs 117012002. Make sure the shear value fv for the species and grade you use exceeds the fv listed in the span table.

The only reason a structural ridge beam would be needed is if there werent any collar ties or ceiling joists to resist the outward pressure being put on the walls from the downward force of the roof acting in the rafters. How to calculate a ridge size if youre using collar ties why is a structural ridge beam even needed at all. Also see assumptions for table development. Roof ridge beams tables 15 20 apply to beams carrying only uniformly distributed roof loads.

If you size a roof beam like a structural ridge that has a l240 limitation you would multiply the minimum e value by 0666 785000 x 0666 522810 in this case. This is set by the roof use you selected in the previous screen and cannot be modified. Notes for tables 15 20. See assumptions for table development beginning on page 2 for details on design assumptions made to generate these tables.

Loading conditions are detailed below. Ridge beam single span. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. A ridge board is a non structural member that serves as a prop for opposing rafters to rest against and connect to.

According to the 2012 irc codes any beam joist or header shall never have a bearing of less than 1 12. Beam size is based on the load transferred from 12 the span of the supported roof framing. Anything 5 and above we always at least double cripple. Ridge beams are required by code if the roof slope is less than 3 in 12 irc section r8023.

You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. Live load 30 psf dead load 14 psf dead load manually increased for roof slope total load 44 psf span is 16 0 to center of posts supporting ridge beam. Duration of load is 115 snow tributary length 12 0 exclude outer 6 ft of rafters which bear on outside walls the ridge beam. The imposed uniformly distributed live load on the overhang.

Structural ridge beam sizing mojoman posted in construction techniques on may 15 2004 1220pm what size ridge beam would i need to support a cathedral gable roof that is about a 412 pitch 14 long and spans 16 wall to wall. For each application a pdf download is available.