How Many Squares Roofing Felt Do I Need

Determine the number of rolls of underlayment needed.
How many squares roofing felt do i need. To determine the number of squares on the gable roof above simply divide its total of 24 000 square feet by 100. Roofing is sold in 100 square foot lots so you need 21 squares of shingles and 2 100 square feet of 15 pound 15 felt paper and about 50 pounds of galvanized roofing nails. If the slope is between 3 12 and 4 12 double the amount and put down 2 layers. The most common type of shingle called a three tab or strip shingle is generally packaged three bundles per square.
Roofing felt is sold by the roll. Rolls of felt are 36 wide x 144 long for 15 and 72 long for 30. The most common roofing materials used in the united states include shingles membrane roofing and ceramic tile all of which have different life spans. The 15 type is most commonly used and one roll of 15 underlayment covers 4 squares.
Figure about 450 square feet of felt. The result is 240 and this means you would need 240 squares of shingles to cover that roof. The average roll of 15 pound roofing felt covers about 400 ft 2 or 4 squares while the average roll of 30 pound roofing felt covers about 200 ft 2 or 2 squares. Always double check with the roofing calculator to make sure that you have enough felt to cover the entire area of the roof.
1square of roofing covers 100 square feet of roof a bundle is 1 3 of a square. Check that your footage measurements are within this range so you can start off on the right foot. One roofing square equals to 100 square feet. Rolls of felt coverage for roofs is sold in rolls that are one square each.
Remember when estimating required amounts that you need to overlap the felt about. One square is equal to 100 square feet. How many rolls of felt will you need. 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.
For a new roof you will also need the same amount of underlayment. Shingle roofs typically have a life span of 15 30 years while membrane roofs usually last 5 15 years. If you re using 15 underlayment and your roof slope is greater than 4 12 use 1 layer. There are also 29 standard sized shingles measuring 12 inches by 36 inches in each one of these.
A square of shingles is the number of shingles needed to cover 100 sq feet of roof area. Roofing paper or felt normally comes in about 150ft rolls and are 3ft wide. As a rule of thumb there are 3 bundles to a square assuming that you are using three tab strip shingles. I think 185 per square is a decent price to remove and replace shingles.
Roof surfaces are measured in squares a square is an area of roof which measures 100 square feet.