Minimum Roof Pitch For Dormers

Having a steeper pitched roof allows for more space in a shed loft.

Minimum roof pitch for dormers.

However rise over run is more efficient and easier to understand for the average diyer. However you can only use this pitch with built up roofing or specialized synthetic roofing. This type of dormer needs a roof pitch shallower than that of the original. Thus a 4 12 pitch would be a 33 slope.

Pitched roofs can also be used to incorporate roof lights angled in a specific direction or dormer windows. Roofing gutters and all waterproofing anywhere minimum roof pitch i am planning a shed dormer with a roof that will have about 3 12 pitch. The loft space would be much larger with a roof pitch of 45 degrees. The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.

You can also divide the rise over run multiply by 100 and get a percentage.