How To Size Roof Ridge Beam

Ridge beams are required by code if the roof slope is less than 3 in 12 irc section r802 3.

How to size roof ridge beam.

Also see assumptions for table development. If an example roof is 10 feet by 20 feet the total area is 200 square feet. A ridge board is a non structural member that serves as a prop for opposing rafters to rest against and connect to. For 2 x 4 rafters use a 2 x 6 ridge board.

The ridge board s length will be the outside measurement of the building plus the length of the overhang at both ends. 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. Step 1 choose a ridge board that is one size larger than your common rafters. Multiply the load per square foot by the total area of the roof.

Loading conditions are detailed below. 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. Ridge beam height above top of slab height of wall z. Timber steel framing manual single span ridge beam.

These small areas are usually door opening on the interior and people are trained that these areas are the strongest place in a house to be in the case of an emergency. For each application a pdf download is available. 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. Refer to sfpa s publication southern pine headers beams download in publications that includes all size selection and allowable load tables.

Multiplied by 40 pounds per square foot equals 8 000 pounds. Versa lam lvl size chart laminated beam span tables charts. Ridge beam sizing is based on the span of the beam between supports and the amount of roof load supported by the beam. It has been my experience to never use a beam smaller than a two ply 2 x 8.