How To Find Roof Slope Factor

Use a level against the underside of the rafter you re measuring to get the most accurate value.

How to find roof slope factor.

The area of this roof 1073 3 sq. Roof length including overhangs 40. Measure from an exterior wall to an exterior wall and divide by two. Multiply the roof length by the gable wall length 40 24 960.

Gable wall length including overhangs 24. Enter 6 into the calculator slope factor 1 1180. Place your extension ladder against the roof. Then you ll be able to measure slope from an unfinished attic space under the roof.

How to determine roof slope factor 1. Use the factor instead. Using a tape measure make a pencil mark 12 inches from the end of a carpenter s level. You want to find out how much longer that length is than the 12 inches and express the difference as a number the roof slope factor also called the roof slope multiplier roof pitch factor or roof pitch multiplier.

The most precise way to find the roof s slope is by measuring it from the underside. Locate the level s 12 inch mark. 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. Access one of the rafters then take.

Hold out your arms and hands perpendicular to the ground as you stand. How do you calculate the slope of a roof. Multiply the result by the factor and this is the length of the roof from base to ridge. The roofing material should look dry and intact.

Once you know the roof slope multiplier for a particular slope you can use it to find the actual area of any size sloped roof. Multiply this amount by the slope factor 960 1 1180 1073 28.