Calculating the Square Footage of a Gable.
For calculating the square footage of a Gable Wall section you need to know the Gable wall length and the height of the Gable. If for some reason you can't get the height of the Gable, you don't have a ladder long enough or you are one of those that should not be at heights, if you know the pitch of the roof and the wall length you can also calculate the square footage of the gable.
Calculating Gable height knowing wall length and roof pitch.
wall length = 24'
roof pitch = 6/12 = 6" of rise for every 12" of run
Take half the length of the gable wall and convert it to inches.
24 / 2 = 12"
12 * 12 = 144"
Divide this amount by the run of the roof pitch.
144 / 12 = 12. Multiply this 12 by the roof pitch rise.
12 * 6 = 72"
Convert the inches back to feet:
72" / 12 = 6'
At the highest point the Gable is 6' high.
Calculating the Gable's square footage.
Split the Gable into two triangles and form a rectangle
6 * 12 = 72
The total area for your Gable = 72 square feet.