How To Measure A Triangle Roof

For instance a 7 12 roof pitch means that the roof rises 7 inches for every 12 horizontal inches.

How to measure a triangle roof.

If this distance measures 4 inches you have a 4 in 12 pitch. 1 roof square 100 square feet. Locate the level s 12 inch mark. In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches.

Click to enlarge the image. The most precise way to find the roof s slope is by measuring it from the underside. Record this as the roof width. Mathematicians have no special formula for finding the perimeter of a triangle they just add up the lengths of the sides.

Hold the carpenter s level in a horizontal position with one end touching the roof surface. Pitch measurement method 1 1. 8 inches and you have an 8 in 12 pitch. Determine the distance from the edge of the roof to a point on the same plane directly under the highest point.

The basic formula for finding the area of a triangle is the base times the height in this case the distance between the base and the peak. L 30 feet h 12 feet 30 12 2 180 square feet. To find the area of a triangle you need to know the length of one side the base b for short and the height h. This procedure to measure roof slope can be performed on the roof or from a ladder at roof edge.

Outside of the u s a degree angle is typically used. Use a level against the underside of the rafter you re measuring to get the most accurate value. Measure out 12 along the level bottom edge the green line in our sketch. Note that the height forms a right angle with the base.

If you have a roof section that s 30 feet 9 1 m long and 12 feet 3 7 m high multiplying those dimensions would give you an area of 180 square feet 17 m 2. This figure shows a triangle with a base of 5 cm and a height of 2 cm. 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. Access one of the rafters then take the measurement this way.

The length l times the height h of a triangle is twice its area a2.