Water shield may look like traditional felt paper

water shield may look like traditional felt paper Roofing ice and water shield may look like traditional felt paper, but it’s vastly different in performance. Traditional felt paper does a very good job at stopping most leaks where water gets under shingles, tiles, metal or slate. It does this by not allowing the water to come in contact with the wood beneath the actual roofing material.

But felt paper has problems where it overlaps the sheet below and where the nails penetrate the felt. If water backs up under the roof as happens with ice damming, water can flow up and under the lap joints of felt paper.

Where the nails used to attach the roofing materials penetrate felt paper, the hole created is not sealed. Water can get under the head of the nail and seep down the shaft of the nail where it passes through the felt paper. When this happens, you get leaks into your home.