Garage Roof Rafter Spacing

Allowable spans vary according to wood species and the loads.

Garage roof rafter 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. It is always better to have a large rafter rather than be concerned with a sagging roof. In order to build a garage roof you need to use the following. A metal roof must also allow for some overlap on each side of the panels which will reduce the effective width of the panel.

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. The determining factor of post spacing is the allowable span of your beams. In other words the maximum distance it can cover without support from posts. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal.

C 30 pieces of 2 4 lumber 97 1 4 14 pieces 6 1 2 rafters. The closer the rafters are to each other the stronger the roof will be. Rafter spacing is based on the width of the metal roofing panels. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.

However if the spacing is too wide the patio cover s beams will bow under the weight of the joists and roof covering materials. So the space between rafters can be greater without reducing the maximum span. Typical rafter spacing codes will specify a minimum spacing of 16 inches 19 2 inches or 24 inches. 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.

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 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. The same concept holds true for roof trusses. Use these two tables for roof rafters with a slope of 3 in 12 or less.

Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. 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. B 2 pieces of 2 4 lumber 36 1 4 1 piece of 2 6 lumber 260 top ridge.