But did you know that simple data already printed on your framing square can give key roof slope and rafter data.
How to measure roof pitch slope.
How to calculate roof pitch.
The most precise way to find the roof s slope is by measuring it from the underside.
How to obtain roof pitch or slope by using the rafter tables on a framing square measuring the roof slope pitch or rise and run is easy if you ve got a tape measure and more accurate still if you ve also got a level on hand.
Also referred to as roof slope or roof slant so what does the 7 12 in the example to the right mean.
Step 1 access a rafter.
How to determine or calculate roof pitch or roof slope roof pitch calculator is determined by the number of inches it rises vertically for every 12 inches it extends horizontally.
A barge rafter at the side of the gable step 2 position a level against the underside of the rafter.
Place one end of a carpenter s level against the underside of the.
Any of the following will give you a good measurement 1 x research source a rafter in the attic.
You can use the following equations to find the length of the rafter and the slope.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
Access one of the rafters then take the measurement this way.
Rise run pitch where pitch is expressed in percent.
Rafter rise run from the pythagorean theorem.
Generally roof pitch is calculated from the same formula that describes a right triangle.
Locate the level s 12 inch mark.
The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7.