1 4 12 Roof Slope

Pitch angle precision color.

1 4 12 roof slope.

Roof pitch is a term describing how steep or flat your roof slope is. Lapped nonsoldered seam metal roofs with applied lap sealant must have a minimum roof slope of 1 2 12 4 slope. They have a pitch ranging from 4 12 to 9 12. A roof that rises 4 inches for every 1 foot or 12 inches of run is said to have a 4 in 12 slope.

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. For example if you measure 4 inches the pitch of your roof is 4 12. Examples of extreme slopes range from 1 4 12 almost flat to 12 12 sloping down at a perfect 45 degree angle. This will give you the rise over run or pitch.

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. 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. This means for every 12 horizontal units the roof must rise a minimum of one half vertical unit. Generally such roofs have a pitch ranging from 1 2 12 to 2 12.

This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. Enter run the flat level length then click pitch angle or rise to select then enter other known dimension angle or pitch. These roofs have a pitch less than 4 12. Conventional roofs are the easiest to construct and you can walk on them safely.

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. The triangle diagram will be re drawn to scale with all dimensions marked. Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof. Standing seam roof systems must have a minimum roof slope of 1 4 12 2 slope.

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. The combination of two numbers are used to display or show the roof pitch. Most roof s have a pitch in the 4 12 to 9 12 range. The table below shows common roof pitches and the equivalent grade degrees and radians for each.

Low pitched roofs are generally difficult to maintain and you need special materials to prevent leaks. The slope ratio represents a certain amount of vertical rise for every 12 inches of horizontal run.