How To Figure Roof Area

The roof s pitch is the number of inches the roof rises in 12 inches.

How to figure roof area.

The incline or pitch of a roof can be easily measured with a level tape measure and a pencil. Climb to the top of your roof. A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally. Given pitch and a horizontal area measurement multiply the horizontal area by a correction factor corresponding to pitch provided in the table below to determine the actual area of the roof to be used in the roofing material calculator.

So if you divide your answer of a product of length times height by two you will get the area of a triangle. This applies to lengths as well as areas. Next place your ladder against your house at the gable end. L 30 feet h 12 feet 30 12 2 180 square feet.

Roof pitch is given as the number of inches in height change over the distance of one foot. To calculate the area of your roof first you ll need to calculate the pitch of it. For a 12 000 sq ft 1 100 m 2 roof you ll need a minimum of 120 squares. That gives you 5 590 square feet which is the actual area of the surface of the roof.

Depending whether the roof area is measured horizontally possibly from a drawing or photograph a correction factor is necessary to determine the actual area of the roof. To accurately calculate the area of your roof you must first determine its slope or pitch. Therefore mark off 12 inches on the level and place it down horizontally against the roof rafter. Dividing by 12 gives the ratio of inches in rise per distance.

Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. This is expressed in terms of how many inches the roof rises for every foot of horizontal distance. Dividing the total area of your roof by 100 will therefore help you figure out how many squares worth of shingles to order. And that s the number you were looking for.

While it is possible to estimate the amount of necessary materials using only the. Roofing materials are typically packaged in squares each of which is the equivalent of 100 square feet 9 3 m 2 of roof space. Mark a level 12 inches from one end. First use your measuring tape to measure 12 inches on your large level and make a mark at the 12 inch line.

Place the other end of the level at the peak of the roof and hold it level. 1 roof square 100 square feet. The length l times the height h of a triangle is twice its area a2.