Roof Slope 1 4 Over 12 Architectural Note

I e 4 inches of rise per 12 inches one foot of run.

Roof slope 1 4 over 12 architectural note.

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. The slope ratio represents a certain amount of vertical rise for every 12 inches of horizontal run. Since this is a flat roof or nearly flat roof. Roof slopes are most commonly defined by the rise over run ratio.

However roof pitch is technically measured and defined differently and will not be discussed here. A wood shingle is cut whereas a shake is split by. 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. This will give you the rise over run or pitch.

For example if you measure 4 inches the pitch of your roof is 4 12. If a roof slope rises say 4 inches when measured 12 inches along the bottom of a horizontal roof truss the roof slope is said to be 4 12. Low slope roofs are from 0 to 3 12 in pitch. 0 pitch 1 00x the roof area.

The table below shows common roof pitches and the equivalent grade degrees and radians for each. You can measure the roof slope on the bottom side. Some sources consider low slope to include 3 12 pitch roofs. Note that roof pitch is sometimes used in parallel with roof slope.

4 12 is the incline of the roof expressed as. A roof that rises 4 inches for every 1 foot or 12 inches of run is said to have a 4 in 12 slope. Note the roof material. If the rise is 4 feet over a 24 foot span then the roof pitch is 1 to 6 is expressed as a ratio and in inches per foot.

Slopes greater than 18 12 are found on a frame roofs and some mansard style. Simply locate a roof rafter board place the end of the level against the bottom edge and measure from the 12 inch mark vertically to the bottom edge of the rafter. 1 12 roof pitch angle 4 76 degrees. 1 pitch 1 01 2 pitch 1 02 3 pitch 1 03 4 pitch 1 05 5 pitch 1 085 6 pitch 1 12 7 pitch 1 16 8 pitch 1 21 9 pitch 1 25 10 pitch 1 31 11 pitch 1 36 12 pitch 1 42.

If asphalt shingles are to be installed on a low slope roof special steps are required to avoid short roof life and roof leaks. If a roof rises 1 in a length of 12 this is 1 12 roof pitch. However you can only use this pitch with built up roofing or specialized synthetic roofing. You can go by the measurements taken by walking the roof.

See low slope roofing.