How To Find Roof Slope Factor

For example if the pitch of the roof is 6 then it is written as 6 12.

How to find roof slope factor.

This numerical figure is significant as not everybody can understand the technical measurements. One medium to describe the roof pitch is in 12 runs. 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. You don t have to climb a ladder and place a tape measure on the ridge and measure down to the base to find the length of the roof.

Use the factor instead. Using a tape measure make a pencil mark 12 inches from the end of a carpenter s level. For any roof slope expressed as x in 12 rise in run the hip and valley factor is determined by finding the square root of rise run 2. A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally.

Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. Write down the number of inches between the roof and the bottom of the level 12 inches from the roof s peak. The whole table of roof pitch and slope gives a conversion factor so as to obtain a numerical figure of the slope. The roof slope factor is written as x 12 where x is the vertical distance you.

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. The most precise way to find the roof s slope is by measuring it from the underside. To accurately calculate the area of your roof you must first determine its slope or pitch. The maths behind this number is that it is the square root of rise run 2 1.

Divide the rise by the run the run is 12. Access one of the rafters then take the measurement this way. Measure from an exterior wall to an exterior wall and divide by two. Locate the level s 12 inch mark.

Then you ll be able to measure slope from an unfinished attic space under the roof.