What does ice and water shield look like?
On the roll
- Heavier and denser than synthetic underlayment, about 3 feet wide.
- A plastic or paper release liner on the back, often split so it can be peeled in halves.
- The label shows the product name, square feet per roll and usually ASTM D1970.
Two surface types
- Granular: a fine sandy or mineral surface, dark gray or black. It feels like coarse sandpaper and gives good footing.
- Film-surfaced: smooth plastic, often printed with the brand name, logo and lap lines. Some versions are colored or labeled to show they are high temperature products.
In roof photos during a job
Look for a dark band along the eaves, if eaves are covered, and dark strips running down every valley, with patches around pipes, chimneys and skylights. The rest of the deck is usually covered with synthetic underlayment, which is lighter, often gray, white, blue or tan, and fastened with visible plastic cap nails. The membrane has no cap nails across its face because it is adhered, not nailed.
On an old roof during tear-off
Old membrane looks like black, tar-like material stuck to the deck that does not come off with the shingles. That is why decking near eaves and valleys sometimes needs replacing.
Ask for photos
Once shingles are on, you cannot see it. Ask your roofer for photos of the membrane before it is covered. More on what it does in ice and water shield in Georgia, and on the other layer in synthetic underlayment vs felt.