Steepest Roof Pitch Possible

A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof.

Steepest roof pitch possible.

Roofs with extreme pitches either low or steep are inappropriate for certain roofing materials. 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. To start lets discuss how pitch is measured. Asphalt shingles continue to be the most widely installed roof covering option in north america.

Low slope or flat roofs should not be roofed with asphalt shingles because it is much easier for water to infiltrate the roofing material on a roof with a shallow pitch. However from the wind uplift mitigation perspective a 7 12 roof slope can be considered as a two story building due to the higher overall steepness and profile of the roof. A ratio is the most common way of expressing roof pitch or roof slope but degrees are also possible. The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.

The way pitch also known as roof slope is measured is rise over run. While most standard pitched residential roofs seldom exceed a 12 12 pitch 45 degrees the landscape is occasionally marked by a design which harkens back to earlier times when much greater roof pitches were more common. In the united states you typically see pitch described as 8 12 6 12 4 12 etc. Most roof s have a pitch in the 4 12 to 9 12 range.

The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles. However you can only use this pitch with built up roofing or specialized synthetic roofing. The table below shows common roof pitches and the equivalent grade degrees and radians for each. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.

The possibility of slipping and falling makes working on any roof dangerous but it s especially so if the roof rises more than 4 feet for every 12 feet of. A 4 12 pitch is around 18 5 degrees but not exactly. A roof slope of 7 12 is also good and can provide the additional benefit of helping minimize the effects of wind driven rain. Knowing the difference between a steep pitch a low pitch or somewhere in between is something you want to be comfortably informed about when considering roofing changes.

Osha defines a steep roof as any roof with a rise run ratio over 4 12 18 43 degrees. Steep slope roofing is generally referred to as residential roofing due to the fact that most single family homes in the u s. Generally roofing types and roofing products are typically divided up into two primary categories steep slope roofing and low slope roofing. Architecturally described as a dramatic pitch the extremely steep roof esr is.