Gable Roof Ridge Beam Size

Here we have a wood framed gable roof.

Gable roof ridge beam size.

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. Floor beam span tables of residential structural design we will now look at roof rafter and beam design. Continuing on from part 3. This tells you the size of the beam needed to support the porch s roof.

Some shed rafters do not incorporate ridge beams either due to small size or lack of technical know how. Let s consider a basic gable wood roof framing design. The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. This sizing guide for roof rafters will help determine what you need for your small project.

The ridge board s length will be the outside measurement of the building plus the length of the overhang at both ends. Choose a ridge board that is one size larger than your common rafters. Loading conditions are detailed below. However our instructions include making shed rafters with a ridge beam.

There are several variables to consider when determining the proper rafter size. Calculate the initial value for d then round it up to the nearest inch. 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. This means the example porch would need a 6 inch by 8 inch beam.

Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter. For 2 x 4 rafters use a 2 x 6 ridge board. Refer to sfpa s publication southern pine headers beams download in publications that includes all size selection and allowable load tables. In the example d calculates to 7 75.

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. Also see assumptions for table development. A ridge beam runs the length of the shed roof connecting every pair of rafters. For 2 x 6 rafters use a 2 x 8 ridge board and so on.