How To Find Existing Roof Pitch

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

How to find existing roof pitch.

On the roof hold the level perfectly level and measure the height from the roof to the level 12 inches away from where the level touches the surface this will be the rise. Find the tangent of the angle tan angle. First measure 12 inches from one end of the level and make a mark. To convert from degrees to the american ratio.

Total height of building. A 30 roof pitch is roughly the same as a 7 12 roof pitch. Enter any angle or fraction of angle to find pitch. For a roof with the ridge above one wall the span is the same as the run.

Locate the level s 12 inch mark. Roof pitch calculator results explained slope the slope of a roof is represented as x 12 where x is the number of inches in rise for every 12 inches of run. Working from the interior side of the roof you ll need access to a roof rafter to measure the pitch. Use a level against the underside of the rafter you re measuring to get the most accurate value.

Enter any pitch or fraction of pitch to find angle. This is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares. This gives you the pitch of the roof. How to measure roof pitch to measure the roof pitch you ll need an 18 or 24 inch level a tape measure and a pencil.

If you need to find the pitch of an existing roof all you need is a level and a tape measure. For a simple gable roof the span wall to wall will be twice the size of the run wall to ridge horizontally. The slope is the same as the pitch. Then in the attic place the end of the level against the bottom of a roof rafter and hold it perfectly level.

Place the level horizontally along the rafter until it contacts the roof sheathing avoiding any protruding roof nails. Access one of the rafters then take the measurement this way. One method to find the pitch is to climb on the roof and measure the rise for a 12 run.