how do i work out the pitch and degree of fall on a 20 foot garage roof which will be covered with box profile sheeting.
Pitch is based on inches of rise per 12inches of run. Example: 5/12 pitch has a rise of 5 inches per 12 inches of run.
If you are going to use conventional roofing like shingles or metal seamed, you should have a 4 pitch or more.(steeper)
If you are using anything for flat roofs, keep the pitch at 4 or less. (flatter)
Hope that makes some sense to you.
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