Most of the old roof had not had any felt put down - the shingles were put right on the wood. But on the new addition they put a a thick paper down first. It wasn
Synthetic vs. Felt Roof Underlayment: Which Should I Use?
Low-Slope Roof Assembly Failures - GreenBuildingAdvisor
ROOFING PAPER AND PROPER INSTALLATION
Roofing practices: hammering down old nails; new felt paper over old; wavyness
What Is The Best Felt Paper (Underlayment) To Put On Your Roof? - New Heights Roofing
ROOFING PAPER AND PROPER INSTALLATION
Should I Remove Old Roofing Felt? (Must Know This) [2023], 44% OFF
Felt Paper and Shed Roofs
Why Felt Paper Is Used In Roofing
Should I Remove Old Roofing Felt? (Must Know This) [2023], 44% OFF
GMC 36-in x 144-ft 432-sq ft Tar Paper Roof Underlayment at
From Plain To Beautiful In Hours 261 Ridged Metal PVC 2' x 2' Lay-in Ceiling Tile (Covers / 40 sq.ft), Old Tin Roof, 10 Piece
Different Types Of Felt Underlayment For Metal And Shingle, 40% OFF