Flat Roof Pitch Requirements

According to the international building code the typical built up flat roof that uses tar or asphalt goes by the guideline that for every foot 12 inches of a flat roof a minimum of inch must step up or down.

Flat roof pitch requirements.

Built up roofs require a minimum roof pitch of 1 4 12 or greater. These roofs have a pitch less than 4 12. Low pitched roofs are generally difficult to maintain and you need special materials to prevent leaks. Roof pitch multiplier table.

As a roof can be made waterproof even at very shallow or nominally flat roof pitches. The chief reason for having a roof pitch is to redirect water and snow away from the roof and avoid any percolation that might result from stagnation of water on the roof. This pitch might be as low as 1 12. This is the basis for calculating the angle which is approximately a 1 19 degree slope.

Run in degrees and as percentage the minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. Roofs on victorian era houses were often sharply angled with a steep pitch. If you re thinking of installing a flat roof it s important to make sure you are up to date with all the rules and regulations before you begin with a new flat roof construction. Mineral surfaced roll roofing requires a minimum roof pitch of 1 12 or greater.

Asphalt shingles continue to be the most widely installed roof covering option in north america. Flat roofs which aren t perfectly flat require a small slope to allow for water runoff. What is a flat roof. However pitched roofs are still used as roof trusses are a very economic way of spanning between side walls.

Visually this roof appears flat. The minimum roof pitch is also subject to the standards set forth by the various building codes used in the respective regions. Wood shingles require a minimum roof pitch of 3 12 or greater. Pitched roofs are attractive and also.

Think of a classic addams family haunted house with its soaring peaks and you have a. They are common on extensions garages and commercial buildings. However you can only use this pitch with built up roofing or specialized synthetic roofing. Steeper roof pitches are better at shedding rain and snow and are used more frequently in wetter colder areas 2.

As opposed to old built up. Slate and slate type shingles require a minimum roof pitch of 4 12 or greater. Generally such roofs have a pitch ranging from 1 2 12 to 2 12. It was fashionable for modern style homes built in the 1960s to have little pitch just a barely negligible slope to help drain water.

Wood shakes require a minimum roof pitch of 3 12 or greater. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends. Flat roofs are an often lower cost and easier to install alternative to traditional pitched roofs.

Importance of a roof pitch.