TRI-BUILT #15 Asphalt Felt Underlayment, 36 in. x 144 ft., ASTM D226, 4 Square Roll

TRI-BUILT #15 felt is an organic asphalt-saturated roofing underlayment supplied as one 36 in. x 144 ft. roll (4 squares) that meets ASTM D226. Use it under shingles as a traditional water-resistive underlayment layer. One roll weighs approximately 52 lb.

Key Features:

• ASTM D226: Manufactured to ASTM D226, the standard specification for asphalt-saturated organic felt underlayment.
• 4 Squares Per Roll: Each 36 in. x 144 ft. roll covers 4 roofing squares.
• #15 Weight Class: Standard #15 felt weight class for steep-slope roofing.
• Traditional Felt: Asphalt-saturated felt, the time-tested underlayment choice.
• Wide Roll: 36 in. width covers more per course than 18 in. felt.

Specifications Table:

Coverage & How Much You Need:

One roll is 36 in. wide by 144 ft. long and covers 4 roofing squares (approximately 400 sq ft) before lap deduction. Allow for head laps and side laps per the manufacturer’s instructions when estimating rolls needed.

Fit and Compatibility:

Use as a shingle underlayment over the roof deck, beneath asphalt shingles and most steep-slope coverings. Attach with cap nails or cap staples and lap courses per standard felt application practice; ice-and-water barrier at eaves and valleys may still be required by code.

Frequently Asked Questions (FAQ):

Q: How much does one roll cover?
A: One 36 in. x 144 ft. roll covers 4 squares (about 400 sq ft) before lap deductions.

Q: What standard does it meet?
A: It is manufactured to ASTM D226.

Q: Is this #15 or #30 felt?
A: This item is #15 felt.

Q: How is it installed?
A: Roll it horizontally over the deck with proper laps and fasten with cap nails or cap staples per the manufacturer’s instructions.

Q: How heavy is a roll?
A: Each roll weighs approximately 52 lb.

Expert Verdict Reviewed by the SuperArbor Pro Desk

#15 ASTM D226 felt remains the economical choice for standard shingle jobs where a synthetic is not specified. At 36 in. width you gain speed over 18 in. rolls, but plan lap allowances carefully so the 4-square yield works out. Keep rolls dry and flat before and during installation to avoid wrinkles and tears.

Felt underlayment becomes slippery when wet and can tear underfoot; wear non-slip footwear and use fall protection on the roof.

Order TRI-BUILT #15 ASTM D226 felt, 4-square rolls, for your next shingle roof.