How To Find Roof Slope Factor

The most precise way to find the roof s slope is by measuring it from the underside.

How to find roof slope factor.

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. Using a tape measure make a pencil mark 12 inches from the end of a carpenter s level. To accurately calculate the area of your roof you must first determine its slope or pitch.

Divide the rise by the run the run is 12. 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. Measure from an exterior wall to an exterior wall and divide by two. Enter 6 into the calculator slope factor 1 1180 multiply the roof length by the gable wall length 40 24 960 multiply this amount by the slope factor 960 1 1180 1073 28 the area of this roof 1073 3 sq.

This numerical figure is significant as not everybody can understand the technical measurements. The whole table of roof pitch and slope gives a conversion factor so as to obtain a numerical figure of the 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. Use the factor instead.

Multiply the result by the factor and this is the length of the roof from base to ridge. The maths behind this number is that it is the square root of rise run 2 1. Access one of the rafters then take the measurement this way. Use a level against the underside of the rafter you re measuring to get the most accurate value.

Locate the level s 12 inch mark. 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. For example if the pitch of the roof is 6 then it is written as 6 12.

The roof slope factor is written as x 12 where x is the vertical distance you.