Flat Roof Pitch Angle

Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio.

Flat roof pitch angle.

The slope of a roof or pitch is determined by how many inches the roof rises over 1 foot or 12 inches. Although there s isn t any standard pitch of a roof used on all kinds of sloped roofs you can determine the range of pitches by using a roof angle calculator and by considering factors like the local climate and roofing materials. 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. In order to achieve this drop a slightly steeper angle of 1 40 1 44 should be the aim when installing a flat roof as this accounts for surface.

Roofs having a lower pitch have a greater chance of creating water leaks as well as ice damming and so they require an intensive waterproofing system. The roof pitch angle greatly factors into the replacement cost of the roof. Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof. Normally 1 80 0 72 is the recommended minimum angle for a slope and this is universal across the vast majority of flat roofing systems regardless of the materials that they incorporate.

The table below shows common roof pitches and the equivalent grade degrees and radians for each. A steep roof usually sheds water quickly which is quite difficult to work on. What degree angle is a 12 12 pitch roof. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.

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. A 12 12 pitch roof has a pitch angle of 45. To convert between american roofing ratios and pitch degrees follow these steps. Asphalt shingles are appropriate on roofs with conventional pitches between 4 12 and 9 12.

This means that the rise of the slope goes up or down 8 inches for every 12 inches. How roof pitch determines suitable roofing systems. 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. To put it in perspective the angle of this slope would be around 30 degrees.

The combination of two numbers are used to display or show the roof pitch. Roof pitch is a term describing how steep or flat your roof slope is. Find the inverse tangent of the pitch to find the angle in degrees. Divide the first part of the ratio by 12 to work out the pitch.