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.

1 12 roof slope.

This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. 1 12 roof pitch angle 4 76 degrees. 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. 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.

A 4 12 is a roof slope that rises by 4 inches for every 12 inches across. 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. 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. High and low pitch examples two examples at each end of the spectrum.

Using a tape measure make a pencil mark 12 inches from the end of a carpenter s level. Then you ll be able to measure slope from an unfinished attic space under the roof. 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. With insufficient pitch a roof can leak rain and with a pitch too great its stones will fall loose.

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. Mineral surfaced roll roofing can only be installed on roof slopes of 1 12 or greater 8 slope. Display of roof pitches 1 12 through 18 12. Most roof s have a pitch in the 4 12 to 9 12 range.

If a roof rises 1 in a length of 12 this is 1 12 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. This means for every 12 horizontal units the roof must rise a minimum of 1 vertical unit. 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.

Examples of extreme slopes range from 1 4 12 almost flat to 12 12 sloping down at a perfect 45 degree angle.