If the house has an irregular shape measure each part separately figure the separate areas and add them together.
How to measure square foot of a roof.
Shingles and other roofing materials such as underlayment are typically measured in squares that are 10 feet long and 10 feet wide with each square measuring 100 square feet.
1 roof square 100 square feet.
The length l times the height h of a triangle is twice its area a2.
Multiply the length by the width to arrive at the ground area of the house.
For instance a 7 12 roof pitch means that the roof rises 7 inches for every 12 horizontal inches.
Step 1 understand your roof surface a home s roof is measured in squares.
If your roof is 5 000 square feet you will have 50 squares.
If your roof measures 48 feet 15 m x 24 feet 7 3 m multiplying its length by its width would give you a square footage of 1 152 square feet 107 0 m 2.
L 30 feet h 12 feet 30 12 2 180 square feet.
In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches.
Before you do any roofing work you must calculate the roof s square footage to determine how much material you need.
Each square is 100 square feet.
You will need to express this size in terms of square feet.
The first step in a free roofing estimate is measuring the roof dimensions.
Keep in mind that the average size of a roof is 1 700 square feet so your total will likely be 10 higher or lower than this figure.