Roof Rafter Size And Spacing

If your local building authority has a rafter spacing code you may not space rafters wider than required by code.

Roof rafter size and spacing. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. Spacing in 12 16 19 2 24. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. Live load is weight of furniture wind snow and more.

If you get premium kiln dried lumber then you could span 10 5 with the same size of lumber and. 3 stud construction standard utility. There is no standard spacing it depends on what size of rafters you want to use and the span of your shed. 1 ft 0 3048 m.

For instance 2 grade 2x4s at 16 on center will span just over 9. An essential part of planning a patio roof or gazebo project is determining the number size and spacing of rafters beams and posts according to the loads they will carry. Floor beam span tables of residential structural design we will now look at roof rafter and beam design. For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2.

It is always better to have a large rafter rather than be concerned with a sagging roof. Here we have a wood framed gable roof. Our roof rafter calculator tools are handy for calculating the number of rafters needed rafter length calculator lineal feet of rafter board feed in ridge and sub facia and the total board feet in the roof. For standard shed roof rafter spacing see rafter span chart.

2 are indicated below. Continuing on from part 3. So the space between rafters can be greater without reducing the maximum span. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal.

Typical rafter spacing codes will specify a minimum spacing of 16 inches 19 2 inches or 24 inches. Floor joists ceiling joists rafters snow load rafters roof live load deflection limit. L 720 l 600 l 480 l 360 l 240 l 180. Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes.

Let s consider a basic gable wood roof framing design. The same concept holds true for roof trusses. 1 psf lb f ft 2 47 88 n m 2. The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial.

2x4 2x6 2x8 2x10 2x12. Common spacing for trusses on this type of building is often between 2 and 4 feet but trusses built with advanced designs may allow spacing as great as 8 or 12 feet.