1 2 Pitch Roof

Roof pitch defined and explained.

1 2 pitch roof. Pitch is the term used to describe the angle slope or slant of your roof. Flat and nearly flat roofs a pitch of 1 in 12 or 2 in 12 cannot be covered with shingles or shakes of any material since there is not enough angle to combat the danger of blow off. The best roof pitch depends on the style of roof you are going for. Conventional from 4 12 1 in 3 to 9 12 3 in 4.

The table below shows common roof pitches and the equivalent grade degrees and radians for each. 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. 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. How roof pitch determines suitable roofing systems.

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. Or the colon can replace the slash as in 2 12 or 7 12. You can assess this in two ways either as the roof pitch angles which the rafters make with the horizontal or the proportion between the run and the rise of the roof. Use our roof pitch calculator to find the pitch of your roof or find the pitch multiplier then multiply the area of the footprint of your roof by the multiplier to find the actual area.

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. The pitch fraction represents a certain amount of vertical rise over the entire span. The combination of two numbers are used to display or show the roof pitch.

The ratio can be indicated by a division slash separating the numbers such as 2 12 or 7 12. Often you express roof pitch as the ratio between the rise and the run in the form of x 12. If your roof is not flat and you cannot climb to the peak to get accurate width measurements then you can add a multiplier for the pitch of your roof. For example given a roof with a rise of 4 feet and a span of 24 feet the pitch is 1 to 6 pitch which can be expressed as the fraction of 1 6.

On blue prints architects engineers usually display the pitch of a roof in the format shown on the image where number 4 represents a rise and number 12 represents a length. For a gothic style the rafters must equal the span 60 while an elizabethan style requires the rafters to be longer than the span. Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof. Roof pitch designations are comprised of two numbers indicating a ratio.