1 4 Roof Slope

The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches.

1 4 roof slope.

Conventional from 4 12 1 in 3 to 9 12 3 in 4. Examples of extreme slopes range from 1 4 12 almost flat to 12 12 sloping down at a perfect 45 degree angle. If the rise is 6 inches for every 12 inches of run then the roof slope is 6 in 12 the slope can be expressed numerically as a ratio. A 4 12 is a roof slope that rises by 4 inches for every 12 inches across.

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. This forms an angle of 18 5 between the horizontal section and the roof and creates a gentle incline that is seen as a midpoint between a low pitch and medium pitch roof. High pitched roofs often need extra fasteners and their pitch can be as high as 21 12. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.

The basic ranges of pitch are not uniformly defined but range from flat which are not perfectly flat but sloped to drain water up to 1 2 12 to 2 12 1 in 24 to 1 in 6. That s the same as a 14 degree slope or a 25 slope. They have a pitch ranging from 4 12 to 9 12. This means for every 12 horizontal units the roof must rise a minimum of one fourth vertical unit.

These roofs have a pitch less than 4 12. You can also calculate roof pitch even without using a roof slope calculator. For most home styles roof pitches fall in a range 4 12 a moderate slope up to 8 12 fairly steep. While roof slope is typically expressed in rise it can also be expressed in degrees or in percent of slope.

Low slope roofing which requires special materials and techniques to avoid leaks and ranges from 1 12 2 12 to 4 12 1 in 3. Conventional roofs are the easiest to construct and you can walk on them safely. The table below shows common roof pitches and the equivalent grade degrees and radians for each. This means that the rise of the slope goes up or down 8 inches for every 12 inches.

A 3 in 12 roof rises 3 for every 12 of run. Most roof s have a pitch in the 4 12 to 9 12 range. Why is the roof slope 25. 3 of rise per 12 of run is the same as 1 of rise per 4 of run or 1 4 25.

To put it in perspective the angle of this slope would be around 30 degrees. Liquid applied roofing must have a design roof slope of 1 4 12 or greater 2 slope.