How To Determine Roof Pitch With A Speed Square

Place the pivot point against the shingles.

How to determine roof pitch with a speed square.

Measure the rise of your roof. Then place a torpedo level on the fat base of the rafter square and. Hold the 0 mark of the tape measure against the roof. The rise over run numbers give you the pitch.

Next hook the tape measure to the level where it meets the sheathing and extend it out to make a mark at 12 in. Pitch rise run 1 5 6 25. Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m. Move the tape measure along the the roof until it hits the level at exactly the 12 inch mark.

Would be the run. Remember that pitch is calculated as the height or rise of a roof pitch over 12 inches of horizontal run. Roof pitch is expressed as rise over run so 12 in. Constructing a new shed roof at the desired pitch is as easy as knowing how to use a speed square.

Let s say it is equal to 1 5 m. Set the level on the edge of the speed square as shown below then place the heel of the speed square on a rafter or gable edge of the roof. How to use your speed square. Mark and measure up to the roof deck to get the rise.

Extend it upward so it is perpendicular to the level. Place the pivot point on the square against the bottom of the rafter and align the 90 degree angle side of the square with the pencil mark. Therefore if your roof rises 4 inches over the course of 12 inches of horizontal run then your roof pitch is 4 12. To calculate the required rafter length multiply the total run length half the building width plus the width that the roof is to overhang the house wall by this number 13 42.

Calculate the roof pitch as the proportion of rise and run. Use a level and a pencil to make a plumb vertical line on one face of an existing rafter. Then place your tape at the 12 in. Measure with a speed square a speed square and level can be used to easily find the pitch of a roof.

How to measure roof pitch with a speed square.