18 12 Roof Pitch Factor

Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.

18 12 roof pitch factor.

On blue prints architects engineers usually display the pitch of a roof in the format shown on the image where number 4 represents a rise and number 12 represents a length. For example if you measure 4 inches the pitch of your roof is 4 12. The roof pitch factor will help in figuring out the exact roof estimate. The last step is to come off the ladder and simply multiply the factor determined in the step above with the number of total squares of the area.

Roof pitch is used to describe the slope or angle of the roof. On a related note the pitch properly the slope of a hip or valley rafter will not be the same as the pitch of the adjacent roof sections. If you have already decided that you are going to have pitched roof on your house then you have made a nice decision. The roof pitch factor is also used to calculate the length of common rafters.

Slope factor chart pitch of roof slope factor 3 12 1 0308 1 4362 4 12 1 0541 1 4530 5 12 1 0833 1 4743 6 12 1 1180 1 5000 7 12 1 1577 1 5298 8 12. A roof pitch of 4 in 12 4 12 has a rise of 4 and a run of 12. Pitched roof provide you protection again heavy rains. Image 1 12 to 12 12 roof pitch 7 12 pitch.

There are lots of advantages that you can get by having pitched roof on your house as compare to flat roof. Roof pitch factor calculator. 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. Roof pitch degree table.

This will give you the rise over run or pitch. In that case the multiplier is multiplied by the run of the rafter the horizontal distance that will be covered by the rafter. This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees. While the slope of the common rafters are expressed as x in 12 the slope of the hip and valley rafter on the same roof will be x in 16 97 so where two roof sections intersect to form a 90 angle a regular hip or valley and each roof.

In order to calculate roof pitch find every inch the roof will rise for every 12 it runs or spans. In our example the roof pitch was calculated as 9 12 which has a factor of 1 25 in the table. A roof with a 6 rise for every 12 run has a 6.