Garage Roof Rafter Spacing

The determining factor of post spacing is the allowable span of your beams.

Garage roof rafter spacing.

The same concept holds true for roof trusses. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. Rafter spacing is based on the width of the metal roofing panels. In order to build a garage roof you need to use the following.

Allowable spans vary according to wood species and the loads. The closer the rafters are to each other the stronger the roof will be. We are using 24 spacing for the roof rafters so the trick is to get the first jack rafter located using the dimensions shown and then you can go quickly by measuring 24 edge to edge for the remainder of each wall. Wider panels allow for greater spacing between rafters.

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. In other words the maximum distance it can cover without support from posts. If your local building authority has a rafter spacing code you may not space rafters wider than required by code. A metal roof must also allow for some overlap on each side of the panels which will reduce the effective width of the panel.

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. C 30 pieces of 2 4 lumber 97 1 4 14 pieces 6 1 2 rafters. Pole barn roof truss spacing generally tens to operate according to similar spacing principles though there are some proponents of having higher pole barn roof truss spacing. 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.

B 2 pieces of 2 4 lumber 36 1 4 1 piece of 2 6 lumber 260 top ridge. Especially when steel roof truss spacing is concerned some engineers would argue that it is possible to only have a roof truss spacing of four feet off center even eight feet has been suggested. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. Use these two tables for roof rafters with a slope of 3 in 12 or less.

So the space between rafters can be greater without reducing the maximum span. It is always better to have a large rafter rather than be concerned with a sagging roof. Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes.