1 12 Roof Slope

For most home styles roof pitches fall in a range 4 12 a moderate slope up to 8 12 fairly steep.

1 12 roof slope.

The minimum slope for lapped non soldered seam metal roofs with applied lap sealant shall be one half unit vertical in 12 units horizontal 4 percent slope. A 4 12 is a roof slope that rises by 4 inches for every 12 inches across. The minimum slope for lapped non soldered seam metal roofs without applied lap sealant shall be three units vertical in 12 units horizontal 25 percent slope. The table below shows common roof pitches and the equivalent grade degrees and radians for each.

A 4 12 slope is enough to accommodate water runoff but is not suitable for regions that are. Examples of extreme slopes range from 1 4 12 almost flat to 12 12 sloping down at a perfect 45 degree angle. Display of roof pitches 1 12 through 18 12. 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. High and low pitch examples two examples at each end of the spectrum. If a roof rises 1 in a length of 12 this is 1 12 roof pitch. Then you ll be able to measure slope from an unfinished attic space under the roof.

Using a tape measure make a pencil mark 12 inches from the end of a carpenter s level. 1 12 roof pitch angle 4 76 degrees. Thatch is one of the oldest roofing materials and needs a steep pitch to drain properly some types of stone roofs have a very restrictive roof pitch. 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.

Mineral surfaced roll roofing can only be installed on roof slopes of 1 12 or greater 8 slope. This means for every 12 horizontal units the roof must rise a minimum of 1 vertical unit. This forms an angle of 18 5 between the horizontal section and the roof and creates a gentle incline that is seen as a midpoint between a low pitch and medium pitch roof. Slope ratio a roof that rises 4 inches for every 1 foot or 12 inches of run is said to have a 4 in 12 slope.

This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.