Roof Area Formula

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Roof area formula.

Divide your roof pitch by 12. Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. 6 calculate the total surface area of the roof using the following formula. The roof area is simply 114x18x2 plus 30x18x2 giving 5184 square feet which is perfectly adequate for estimating materials.

Double click in the roof angle column of the area measurement type the roof angle and press enter. The answer to this is the total number of squares on your roof for which you need to purchase shingles. Divide the area you calculated in step 4 by 100. The roof area is calculated.

A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally. Measure the length of the rafters from the peak to the lower edge. In the construction industry roofs are measured in squares one square equals 100 square feet. Multiply your house length by your house width to get the area.

Which is the same as saying a 45 degree slope a 12 in 12 slope or the roof will rise 12 for every 12 of horizontal run. Details of that procedure are at roof measurements. Roof pitch is given as the number of inches in height change over the distance of one foot. Select the area measure.

You may want to hide the display of the area value in the plan view to avoid confusion. For example 40 feet x 30 feet 1 200 square feet next multiply the area by your roof s pitch. Pi times the radius times the rafter length also. The roof area for a hip end is the same as for a gable end the intersection is equivalent to a hip slightly conservative so there is usually no need to consider triangles when measuring a roof.

Right click on the area measure then click properties. Explanation of the formula. To accurately calculate the area of your roof you must first determine its slope or pitch. Dividing by 12 gives the ratio of inches in rise per distance.

We used this detail to calibrate our folding carpenter s rule scale for reading roof slope from the ground. Tan 45o 1 00.