1 8 Roof Factor

Valley hip factor.

1 8 roof factor.

1 20 multiply the feet by 12. If the rise is 4 feet over a 24 foot span then the roof pitch was said to be 1 to 6 the pitch can be expressed numerically as a fraction. For example the roof layer that protrudes above the roof is 1 so add 1 to your tape reading. 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.

That is if your tape reads 7 then add 1 that will give you 8 12. Measure with a speed square. The pitch fraction represents a certain amount of vertical rise over the entire span. 20 x 12 scale factor 240.

Then multiply the square footage with the roof pitch factor to get the total area of the roof. 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. The roof slope factor chart also consists of conversion factors to determine the slope of the roof. 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.

Roof pitch degree table. To convert an engineering drawing scale to a scale factor. This will give you the rise over run or pitch. A roof pitch multiplier also known as a roof pitch factor is a number that when multiplied by the area covered by a sloped roof gives the actual area of the roof.

Image 1 12 to 12 12 roof pitch 7 12 pitch. The maths behind this number is that it is the square root of rise run 2 1. Set the level on the edge of the speed square as shown below then place the heel of the speed square on a rafter or gable edge of the roof. 1 8 1 0 invert the fraction and multiply by 12.

A roof that rises 8 feet over a 24 foot span was said to have a 1 to 3 pitch. To convert an architectural drawing scale to a scale factor. For example given a roof with. 8 1 x 12 scale factor 96.

For example if you measure 4 inches the pitch of your roof is 4 12. The headache of using pythagoras and trigonometry can be spared by making use of these charts. A speed square and level can be used to easily find the pitch of a roof. A 10 slope roof should not be confused with a 10 pitch roof as a 10 slope roof means that the roof rises by ten inches for every foot of run.

The calculator above can handle much of this math.