Thickness Of Roof Rafters

Once all of these inputs have been entered into the calculator you will see that the appropriate rafter width is 120 33 inches.

Thickness of roof rafters.

In addition using the rafters diagram you can see the precise dimensions of the roof rafter including length from every possible angle. Sheathing should be a minimum of 19 32 inch thick. Roof sheathing comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame. Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes.

If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length. See rafter run to outer wall calculator below. The typical thickness range for sheathing is 3 8 to 3 4 inch. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.

It is always better to have a large rafter rather than be concerned with a sagging roof. Rafters are the structural beams that support the weight of the roof sheathing and the shingles. For instance if your roof has a steep pitch you may be able to use 2 inch by 4 inch rafters but if your roof has a low pitch building code may require that you used 2 inch by 6 inch or 2 inch by 8 inch rafters. Includes result for hip valley factor slope factor and the roof slope in degrees.

Never attach roof sheathing with staples. Here the wall thickness is 240 57 inches. 8d ring shank nails should be used instead. How thick should a roof be.

That will suffice on a roof with rafters set 16 inches apart with minimal roof loads. Loads will vary with the. As roof pitch is lowered the weight burden on the rafters increases. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement.

Half building width minus 1 2 ridge thickness. Minimum thickness most roofs will be sheathed in plywood at least 3 8 inch thick. For low pitch roofs building codes may require larger dimension rafters. Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch.