Roof Pitch Multiplication Factor

Roof pitch factor calculator.

Roof pitch multiplication factor.

In our example the roof pitch was calculated as 9 12 which has a factor of 1 25 in the table. A roof pitch multiplier also called a roof pitch factor is a number that is multiplied by the area covered by a sloped roof to produce the area of the actual surface of the roof. If the home measures 20 x 40 and has a 7 12 roof then to calculate the slope of the roof follow these steps. If you have already decided that you are going to have pitched roof on your house then you have made a nice decision.

Pitched roof provide you protection again heavy rains. Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof. To find the roof pitch you need to place a level across the top ridge with a 12 mark that rests directly above the center top of the ridge. The roof pitch factor will help in figuring out the exact roof estimate.

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 roof slopes expressed as x in 12 rise in run the roof pitch multiplier is determined by finding the square root of rise run 1. 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.

There are lots of advantages that you can get by having pitched roof on your house as compare to flat roof. To obtain an accurate roof pitch measurement properly measure the rise and run. From the roof pitch factor table note down the roof pitch conversion factor corresponding to the roof pitch calculated. 800 multiplied by 1 16.

The combination of two numbers are used to display or show the roof pitch. You need to first figure out the dimensions of the roof by multiplying the length with width to calculate the square footage. Dividing the house width by two equals 14 feet. Step 1 multiply 20 and 40 which equals 800.

Step 2 find the value of 7 12 from the roof slope multiplier table which is 1 16. Looking at the chart the factor is 1 0541. Step 3 multiply step 1 and step 2 i e.