How To Measure Roof Slope

Measuring slope from the roof surface 1.

How to measure roof slope.

The slope of a roof affects the cost of construction as well as the curb appeal of the house. 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. 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. Measuring the slope from the roof surface may not produce the most accurate measurement because of the inherently uneven surface of the roof covering.

Locate a roof rafter board that is readily accessible to you. Use a level against the underside of the rafter you re measuring to get the most accurate value. Climb up a ladder without your tools to take a look at the roof surface. If this distance measures 4 inches you have a 4 in 12 pitch.

Measure 12 inches on a carpenter s level. First measure 12 inches from one end of the level and make a mark. How to calculate roof pitch. On a ladder beside the roof place the level a foot or so up the roof hold it level and measure from the 12 inch mark on the level s bottom straight down to the roof.

Confirm the roof is safe to walk on. Access one of the rafters then take. Mark the length with the marker. Now measure vertically from the 12 inch mark on the level straight up to the underside of the rafter as illustrated.

Generally roof pitch is calculated from the same formula that describes a right triangle. The most precise way to find the roof s slope is by measuring it from the underside. Rise run pitch where pitch is expressed in percent. Also referred to as roof slope or roof slant so what does the 7 12 in the example to the right mean.

Then in the attic place the end of the level against the bottom of a roof rafter and hold it perfectly level. 8 inches and you have an 8 in 12 pitch. You can use the following equations to find the length of the rafter and the slope. Place the end of the level against the bottom edge of a roof rafter and hold it perfectly level.

Determining the slope or pitch of a roof is a simple mathematical. Crawl into the unfinished attic space. Rafter rise run from the pythagorean theorem. How do you calculate the slope of a roof.

This is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares. How to measure roof slope angles.