A metal roof must also allow for some overlap on each side of the panels which will reduce the effective width of the panel.
Rafter spacing for metal roof.
You have to take the width of your roofing panel into the considerations.
Rafter spacing is based on the width of the metal roofing panels.
The most common measurement used for rafter spacing is either 16 or 24 inches.
Rafter spacing for metal roof.
Do not use pressure treat wood for the purlins it will eat up the metal roofing and screws.
Wider panels allow for greater spacing between rafters.
The same concept holds true for roof trusses.
It is always better to have a large rafter rather than be concerned with a sagging roof.
2 4 rafters can span up to 7.
If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.
For heavy loads 2x4s can span up to 5.
Keep it at 24.
Posted in metal roof roof types.
Determining rafter s spacing is as important as setting the metal roof purlins spacing.
Spacing your 2 4 shed rafters at 24 on center limits the width of your roof.
Most roof framing is 24 on center and you can still build sheds up to 14 with 2 4 rafters at 24 on center.
Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes.
So the space between rafters can be greater without reducing the maximum span.