Underlayment
The waterproof layer installed between your roof shingles and the wood deck underneath.
Why It Matters for Homeowners
Why it matters: when we replace a roof, we strip down to the deck and replace the underlayment - on every job. That is how the new roof ends up on a clean surface instead of on top of something we could not see. Modern underlayment options include synthetic membrane, rubberized asphalt (self-adhering), and traditional asphalt-saturated felt. In California, ice and water shield is often added at eaves and in valleys.
Related searches: roof underlayment, roofing felt, synthetic underlayment