How Much Roof Tar Do I Need

Roofing felt is a layer of tar paper installed beneath the shingles to provide a backup waterproof membrane in case of leakage.

How much roof tar do i need.

Multiply the total area determined in step one by a correction factor to account for the roof pitch. Most experts tend to say that if that if more than 25 of a tar and gravel roof is covered in patches then the roof needs to be entirely replaced. 1square of roofing covers 100 square feet of roof a bundle is 1 3 of a square. Rolls of felt are 36 wide x 144 long for 15 and 72 long for 30.

Get the square footage of roof and divide it by 100 and it will give the number of squares you need and for every decimal number over 3 buy a bundle to achieve the amount of material. 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. For roof pitches of 5 12 to 7 12 use a factor of 1 3. If the slope is between 3 12 and 4 12 double the amount and put down 2 layers.

Use 1 4 for up to a 9 12 pitch. Buy about 10 percent extra. Feel free to consult with a roofing specialist about your options. If you re using 15 underlayment and your roof slope is greater than 4 12 use 1 layer.

Determine the number of rolls of underlayment needed. The following article will help you understand the process for doing this yourself. Gaf timberline hdz charcoal algae resistant laminated high definition shingles 33 33 sq. The answer is the number of square feet of roofing tar paper you need to purchase.

Consider other underlayment options as needed such as rubber or tar products. This correction factor will take into account the greater area of the roof due to the pitch. If the asphalt calculator outputs you require 10 tons of asphalt you should instead purchase 10 5 or 11 tons to be on the safe side and avoid unnecessarily high transportation costs. You can apply roofing tar to a slanted roof if you want but there typically is not much need.

Use a ladder to reach the bottom level. If your roof pitch is 3 12 or 4 12 multiply by 1 25. The 15 type is most commonly used and one roll of 15 underlayment covers 4 squares. I would agree that there is no urgent need to fix it.