Rolls of felt coverage for roofs is sold in rolls that are one square each. One roofing square equals to 100 square feet. Always double check with the roofing calculator to make sure that you have enough felt to cover the entire area of the roof.
How many squares is a 15 pound felt roll?
ASTM Type 15 Felt Roll.
How many squares is a roll of underlayment?
Roofing felt rolls are 3-feet long and cover about 400 square feet. Synthetic underlayment rolls are 4-feet long and cover closer to 1000 square feet.
How many square feet is a roll of roofing underlayment?
As we compare synthetic underlayments to standard asphalt saturated felt, remember that #15 felt typically comes in 432 square foot rolls and #30 felt typically comes in 216 square foot rolls.
How do you calculate roof underlayment?
Once you know how many squares your roof is, it's pretty easy to estimate the amount of underlayment your job will require. A roll of underlayment will usually cover 4 squares. So, just divide your total number of squares by 4. The result will tell you how many rolls of underlayment you'll need.Mar 20, 2018
How much felt do I need?
How Many Rolls of Felt Will You Need. Roofing felt is sold by the roll. The average roll of 15-pound roofing felt covers about 400 ft2, or 4 squares, while the average roll of 30-pound roofing felt covers about 200 ft2, or 2 squares. Rolls of felt are 36″ wide x 144′ long for 15# and 72′ long for 30#.