Roof Pitch Requirements

Match pitch of existing roof.

Roof pitch requirements.

Match roof material. Anything above that will require you to put out higher cost because they are already considered as higher pitch. Buildings with multiple roof. 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.

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. For every 12 horizontal feet the roof changes 8 feet in vertical height. For most home styles roof pitches fall in a range 4 12 a moderate slope up to 8 12 fairly steep.

Whichever roof pitch you choose make sure that you select a roof covering that is designed. The standard of lower pitch actually ranges between 1 12 to 5 12. Asphalt shingles continue to be the most widely installed roof covering option in north america. A ratio is the most common way of expressing roof pitch or roof slope but degrees are also possible.

Examples of extreme slopes range from 1 4 12 almost flat to 12 12 sloping down at a perfect 45 degree angle. The way pitch also known as roof slope is measured is rise over run. But since there is still a wide variety of slate roofing systems there are occasions when the minimum pitch can go down to as low as 15 0 depending on the uniqueness of the roof. Let us recap on the minimum roof pitch required for each type of roofing material.

The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. The minimum pitch is typically 3 12 meaning the roof should rise 3 inches for every 12 inches of horizontal foot. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.

The covered porch roof pitch should match the existing house. The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. Roof pitches due to zoning and planning requirements. Metal roof shingles require a minimum roof pitch of 3 12 or greater.

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.