Simply put it s a shallow roof.
2 in 12 roof slope.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
Divide the rise by the run and multiply by 100.
The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code.
Asphalt shingles can only be installed on roof slopes of 2 12 or greater.
Also if asphalt shingles are installed on a roof slope of 2 12 to 4 12.
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.
The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof 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.
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 table below shows common roof pitches and the equivalent grade degrees and radians for each.
Roof pitch refers to the slope which the rafter creates.
I am going to be roofing a building that has some areas that are 2 in 12 pitch.
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 horizontal or the proportion between the run and the rise of the roof.
For a 3 8 inch in 12 inch slope.
This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units.