Roof Pitch Requirements

The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.

Roof pitch requirements.

The covered porch roof pitch should match the existing house. Asphalt shingles continue to be the most widely installed roof covering option in north america. With regards to the pitch the building standard code bs 5534 recommends a minimum pitch of 200 for slate roofs. For example the international building code 2018 edition ibc 2018 prescribes a 1 4 12 minimum roof slope for asphalt built up polymer modified bitumen thermoset and thermoplastic single ply and liquid applied membranes in new construction.

The way pitch also known as roof slope is measured is rise over run. A ratio is the most common way of expressing roof pitch or roof slope but degrees are also possible. Asphalt shingles require a minimum roof pitch of 2 12 or greater. Buildings with multiple roof.

Anything above that will require you to put out higher cost because they are already considered as higher pitch. Match pitch of existing roof. Let us recap on the minimum roof pitch required for each type of roofing material. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.

The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. Your shed roof pitch may also be influenced by your project specific requirements to let light into the building through the roof or create storage space in the roof void. Clay and concrete tile requires a minimum roof pitch of 2 1 2 12 or greater. Examples of extreme slopes range from 1 4 12 almost flat to 12 12 sloping down at a perfect 45 degree angle.

For most home styles roof pitches fall in a range 4 12 a moderate slope up to 8 12 fairly steep. Metal roof shingles require a minimum roof pitch of 3 12 or greater. Whichever roof pitch you choose make sure that you select a roof covering that is designed. So if your roof rises 4 inches for every 12 inches of horizontal length then the pitch of your roof is expressed as 4 12.

Minimum roof pitch for a covered porch minimum roof pitch. Match roof material. Roof pitches due to zoning and planning requirements. The standard of lower pitch actually ranges between 1 12 to 5 12.

The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.