Roof Pitch Requirements

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.

Roof pitch requirements.

The minimum pitch is typically 3 12 meaning the roof should rise 3 inches for every 12 inches of horizontal foot. Asphalt shingles continue to be the most widely installed roof covering option in north america. Clay and concrete tile requires a minimum roof pitch of 2 1 2 12 or greater. The way pitch also known as roof slope is measured is rise over run.

The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. For most home styles roof pitches fall in a range 4 12 a moderate slope up to 8 12 fairly steep. 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. Roof pitches due to zoning and planning requirements.

Metal roof shingles require a minimum roof pitch of 3 12 or greater. 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. A ratio is the most common way of expressing roof pitch or roof slope but degrees are also possible.

Whichever roof pitch you choose make sure that you select a roof covering that is designed. The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. 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 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. Asphalt shingles require a minimum roof pitch of 2 12 or greater. Let us recap on the minimum roof pitch required for each type of roofing material.

For every 12 horizontal feet the roof changes 8 feet in vertical height. 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. 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.