1 4 12 Roof Slope

Conventional from 4 12 1 in 3 to 9 12 3 in 4.

1 4 12 roof slope. Most roof s have a pitch in the 4 12 to 9 12 range. This will give you the rise over run or pitch. Roofs at the lower end of the range about 4 12 to 6 12 are relatively easy to walk and work on. 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.

A handy roof slope estimator can help you determine if your roof slope is likely too low for shingles. Lapped nonsoldered seam metal roofs with applied lap sealant must have a minimum roof slope of 1 2 12 4 slope. Low slope roofing which requires special materials and techniques to avoid leaks and ranges from 1 12 2 12 to 4 12 1 in 3. Examples of extreme slopes range from 1 4 12 almost flat to 12 12 sloping down at a perfect 45 degree angle.

This means for every 12 horizontal units the roof must rise a minimum of one half vertical unit. The slope ratio represents a certain amount of vertical rise for every 12 inches of horizontal run. The basic ranges of pitch are not uniformly defined but range from flat which are not perfectly flat but sloped to drain water up to 1 2 12 to 2 12 1 in 24 to 1 in 6. 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.

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. For example if you measure 4 inches the pitch of your roof is 4 12. The table below shows common roof pitches and the equivalent grade degrees and radians for each.

Two most common methods 4 12 or 4 12 are used for marking the pitch of a 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. 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. 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.

A 4 12 is a roof slope that rises by 4 inches for every 12 inches across. The majority of north american residential roofs have historically been constructed with a slope between about 4 12 and 9 12. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.