The table below shows common roof pitches and the equivalent grade degrees and radians for each.
10 in 12 roof slope.
A 2 12 roof slope means your roof has 2 inches of vertical drop for every 12 inches of horizontal distance.
You can assess this in two ways either as the roof pitch angles which the rafters make with the.
Drag sliders to animate the results and diagram.
Enter run the flat level length then click pitch angle or rise to select then enter other known dimension angle or pitch.
Asphalt shingles can only be installed on roof slopes of 2 12 or greater.
Minimum roof slope of.
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.
Asphalt shingles minimum roof slope roof pitch r905 2 2.
Roof pitch is a term describing how steep or flat your roof slope is.
Metal roof panels should be installed on roof slopes according to particular seams 2015 irc r905 10 2.
How do you calculate a roof pitch.
Most roof s have a pitch in the 4 12 to 9 12 range.
The combination of two numbers are used to display or show the roof pitch.
This will give you the rise over run or pitch.
Roof pitch refers to the slope which the rafter creates.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
The minimum roof pitch for shedding snow is around 30 or a 6 12 or 7 12 slope although this is not a definite as the material of your roof the direction of the snow and wind are some factors that can affect whether or not snow will slide as roofs of as little as 10 have been reported to shed snow.
That means the roof doesn t shed water as easily as steeper roofs which is why choosing the right type of roofing material is so important.
This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units.
Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof.
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.
For example if you measure 4 inches the pitch of your roof is 4 12.
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.
Pitch angle precision color.
Built up roofs should be installed on roof slopes 0 25 12 or greater 2015 irc r905 9 1 except for coal tar built up roofs that have a minimum roof slope of one eighth unit vertical in 12 units horizontal 1 slope.