Gable Roof Ridge Beam Size

Here we have a wood framed gable roof.

Gable roof ridge beam size.

The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. Calculate the initial value for d then round it up to the nearest inch. There are several variables to consider when determining the proper rafter size. Some shed rafters do not incorporate ridge beams either due to small size or lack of technical know how.

Gable roof framing calculator plan diagram with full dimensions for a good straight fascia add an extra inch or 2 to the tails of all your rafters total length. A ridge beam runs the length of the shed roof connecting every pair of rafters. This sizing guide for roof rafters will help determine what you need for your small project. Ridge beams are required by code if the roof slope is less than 3 in 12 irc section r802 3.

For each application a pdf download is available. Choose a ridge board that is one size larger than your common rafters. Let s consider a basic gable wood roof framing design. This means the example porch would need a 6 inch by 8 inch beam.

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. Floor beam span tables of residential structural design we will now look at roof rafter and beam design. Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter. The typical gable roof diagram above shows the r length measured from the outside wall to the middle of the ridge beam the rafter section diagram below typical of a shed or patio cover roof shows the r length measured from the outside wall to the outside face of the ridge beam either one is acceptable depending on which type of roof you are building but if you are using the.

The ridge board s length will be the outside measurement of the building plus the length of the overhang at both ends. For 2 x 6 rafters use a 2 x 8 ridge board and so on. This tells you the size of the beam needed to support the porch s roof. Loading conditions are detailed below.

In the example d calculates to 7 75. Continuing on from part 3. For 2 x 4 rafters use a 2 x 6 ridge board. Also see assumptions for table development.