2 X 6 Roof Beam

Floor beam span tables of residential structural design we will now look at roof rafter and beam design.

2 x 6 roof beam. 2 are indicated below. If i tie into a 6 12 pitch roof with 2x6 s. Two 2 by 4 beams together would not be enough. Here we have a wood framed gable roof.

The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. Will i be able to span a concrete slab of 11 6. The architectural graphic standards lists the weight of an exterior 2 6 wall as 16 pounds per ft 2. Dead load weight of structure and fixed loads 15 lbs ft 2.

A two 2 by 6 standard beam has actual dimensions of 1 5 by 5 5 inches which would give a section modulus of 1 5 x 5 5 x 5 5 6 7 6 which is not enough for this example. Loads are contributed to the lower header by the roof upper walls and 2nd floor system. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. My plan is to add 2x6 supports on to the top plates of the existing house wall where the 2x6 s intersect with the walls.

A 2 by 8 beam would be sufficient. 1 ft 0 3048 m. Live load is weight of furniture wind snow and more. If you do opt to use 2 4 shed rafters for your roof construction you will always use a 2 6 ridge beam even though the rafters will be 2 4.

The formula for the section modulus is beam width times beam depth squared divided by 6. Let s consider a basic gable wood roof framing design. 1 psf lb f ft 2 47 88 n m 2. Again this house has the same width dimension but it has 2 levels.

I will be setting 4x4 post every 6 with 2 2x6 s with 1 2 osb sandwiched between them as the form to set on top of post. For more guidance building and installing your rafters see my article on how to build rafters for a shed.