Roof Area Formula

Roof pitch is given as the number of inches in height change over the distance of one foot.

Roof area formula.

Select the area measure. Clear the show caption check box. 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.

Details of that procedure are at roof measurements. Dividing by 12 gives the ratio of inches in rise per distance. The roof area is simply 114x18x2 plus 30x18x2 giving 5184 square feet which is perfectly adequate for estimating materials. Tan 45o 1 00.

Explanation of the formula. Divide your roof pitch by 12. Divide the area you calculated in step 4 by 100. Roof angle is the value in the user defined.

Right click on the area measure then click properties. Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. Area cos roof angle pi 180 area is the value of the area measurement. For example 40 feet x 30 feet 1 200 square feet next multiply the area by your roof s pitch.

Measure the length of the rafters from the peak to the lower edge. A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally. 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.

Double click in the roof angle column of the area measurement type the roof angle and press enter. You may want to hide the display of the area value in the plan view to avoid confusion. We used this detail to calibrate our folding carpenter s rule scale for reading roof slope from the ground. To accurately calculate the area of your roof you must first determine its slope or pitch.

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 answer to this is the total number of squares on your roof for which you need to purchase shingles.