1 12 Roof Slope

Mineral surfaced roll roofing can only be installed on roof slopes of 1 12 or greater 8 slope.

1 12 roof slope.

1 12 roof pitch angle 4 76 degrees. With insufficient pitch a roof can leak rain and with a pitch too great its stones will fall loose. 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. Then you ll be able to measure slope from an unfinished attic space under the roof.

The table below shows common roof pitches and the equivalent grade degrees and radians for each. 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. Display of roof pitches 1 12 through 18 12. A 4 12 slope is enough to accommodate water runoff but is not suitable for regions that are.

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. High and low pitch examples two examples at each end of the spectrum. Examples of extreme slopes range from 1 4 12 almost flat to 12 12 sloping down at a perfect 45 degree angle. For most home styles roof pitches fall in a range 4 12 a moderate slope up to 8 12 fairly steep.

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. 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. If a roof rises 1 in a length of 12 this is 1 12 roof pitch.

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. 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. This means for every 12 horizontal units the roof must rise a minimum of 1 vertical unit. 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.

Using a tape measure make a pencil mark 12 inches from the end of a carpenter s level.