Roof Area Formula

1 200 x 1 05 1 260 square feet to allow for hips ridges and waste add 10 of your final number for a gable roof and 17 of your final number for a cottage roof.

Roof area formula.

Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. We used this detail to calibrate our folding carpenter s rule scale for reading roof slope from the ground. Roof angle is the value in the user defined. 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.

Roof pitch is given as the number of inches in height change over the distance of one foot. The answer to this is the total number of squares on your roof for which you need to purchase shingles. 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. The roof area is calculated.

Measure the length of the rafters from the peak to the lower edge. Divide your roof pitch by 12. Details of that procedure are at roof measurements. For example 40 feet x 30 feet 1 200 square feet next multiply the area by your roof s pitch.

Select the area measure. Tan 45o 1 00. Area cos roof angle pi 180 area is the value of the area measurement. In the construction industry roofs are measured in squares one square equals 100 square feet.

Right click on the area measure then click properties. Divide the area you calculated in step 4 by 100. You may want to hide the display of the area value in the plan view to avoid confusion. Pi times the radius times the rafter length also.

Clear the show caption check box. To accurately calculate the area of your roof you must first determine its slope or pitch. A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally. Multiply your house length by your house width to get the area.

6 calculate the total surface area of the roof using the following formula. Explanation of the formula.