2x8 Or 2x10 For Roof Support

The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial.

2x8 or 2x10 for roof support. The numbers in gray indicate the distance between the support posts. Let s consider a basic gable wood roof framing design. Also available for the android os. The loading includes the weight of the structure and other fixed weights which are defined as the dead load.

Continuing on from part 3. When supporting joists that span 12 feet with no overhang beyond the beam a double ply beam can span in feet a value equal to its depth in inches. 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.

1 ft 0 3048 m. There are several variables to consider when determining the proper rafter size. Here we have a wood framed gable roof. A 2 2x10 can span 10 feet and so on.

Live load is weight of furniture wind snow and more. 2 are indicated below. Dimensional lumber deck beam span chart. A double 2x12 beam can span 12 feet.

You can repeat the same process using a different breadth if you want a beam that is wider or thinner than 6 inches. This means the example porch would need a 6 inch by 8 inch beam. 1 psf lb f ft 2 47 88 n m 2. This tells you the size of the beam needed to support the porch s roof.

Span calculator for wood joists and rafters also available for the android os. Dead load weight of structure and fixed loads 15 lbs ft 2. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.

2x8 2x10 2x12 subfloor installation joist spacing joist spacing joist spacing thickness 12 16 12 16 12 16 a 11 7 11 0 13 8 13 0 15 7 14 10 5 8 b 12 10 12 2 15 1 14 4 17 3 16 5 c 13 1 12 2 15 1 14 1 17 0 15 10 d 13 6 12 4 16 8 15 7 18 9 17 6. The distance you can span a 2 by 10 joist without additional support depends on the species and grade of the wood how far apart the joists are and the expected load on the joists.