1 4 Roof Slope

Why is the roof slope 25.

1 4 roof slope.

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. That s the same as a 14 degree slope or a 25 slope. 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. The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches.

A 3 in 12 roof rises 3 for every 12 of run. 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. Slope ratio a roof that rises 4 inches for every 1 foot or 12 inches of run is said to have a 4 in 12 slope. A 4 12 is a roof slope that rises by 4 inches for every 12 inches across.

You can also calculate roof pitch even without using a roof slope calculator. To put it in perspective the angle of this slope would be around 30 degrees. 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. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.

Most roof s have a pitch in the 4 12 to 9 12 range. While roof slope is typically expressed in rise it can also be expressed in degrees or in percent of slope. The table below shows common roof pitches and the equivalent grade degrees and radians for each. Liquid applied roofing must have a design roof slope of 1 4 12 or greater 2 slope.

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. Examples of extreme slopes range from 1 4 12 almost flat to 12 12 sloping down at a perfect 45 degree angle. Conventional roofs are the easiest to construct and you can walk on them safely. 3 of rise per 12 of run is the same as 1 of rise per 4 of run or 1 4 25.

These roofs have a pitch less than 4 12. They have a pitch ranging from 4 12 to 9 12. An example for a steep sloped roof is 8 12. For most home styles roof pitches fall in a range 4 12 a moderate slope up to 8 12 fairly steep.

High pitched roofs often need extra fasteners and their pitch can be as high as 21 12. The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7.