For Roof Slopes From 2 12 To 4 12

Lapped nonsoldered seam metal roofs with applied lap sealant must have a minimum roof slope of 1 2 12 4 slope.

For roof slopes from 2 12 to 4 12.

Roof pitch is a term describing how steep or flat your roof slope is. A roof that rises 4 inches for every 1 foot or 12 inches of run is said to have a 4 in 12 slope. The majority of north american residential roofs have historically been constructed with a slope between about 4 12 and 9 12. On roof slopes of 2 12 to 4 12 the remainder of the roof shall be two layers of 15 felt applied in shingle fashion or 1 layer of ice dam protection.

The slope of a roof often referred to as the pitch is determined by rise over run the roof s vertical rise in inches for every twelve inches of horizontal length the run. 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 measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. The table below shows common roof pitches and the equivalent grade degrees and radians for each.

If this isn t practical then perform the same measurement on the underside of. 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 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.

Five best practices reasons for using roofing felt underlayment. A 2 12 roof slope means your roof has 2 inches of vertical drop for every 12 inches of horizontal distance. The combination of two numbers are used to display or show the roof pitch. 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.

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. Roofs at the lower end of the range about 4 12 to 6 12 are relatively easy to walk and work on. Simply put it s a shallow roof. So a roof with four inches of rise every 12 inches horizontally run would have a slope of 4 12 sometimes displayed as 4 12.

On 4 12 or greater slopes the balance of the roof shall be one layer of 15 felt. 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 handy roof slope estimator can help you determine if your roof slope is likely too low for shingles. This means for every 12 horizontal units the roof must rise a minimum of one half vertical unit.