Ice and water shield is a specialized underlayment used beneath tab shingles to protect vulnerable areas of your roof from water intrusion caused by ice dams and heavy rain. Ice dams form when heat from the attic melts snow on the roof, which then refreezes near the eaves, creating a barrier that stops melted water from draining off. This trapped water can seep under shingles, causing leaks and damage over time. The ice and water shield is a sticky, rubberized membrane that adheres tightly to the roof deck to prevent water from penetrating, especially around eaves, valleys, and other low points. If you notice recurring leaks during winter or after ice storms specifically near the gutters or deck edges, it’s a good sign your roof could benefit from this extra protection.
For a safe DIY check, inspect your gutters and roof edges for signs of water staining, ice buildup, or loose shingles during cold months. Use binoculars from the ground or a ladder to look for damaged or missing underlayment at these vulnerable spots, but avoid walking on the roof unless you are confident and have proper safety gear. If you’re unsure, it’s wise to call a professional roofer, especially one familiar with local ice dam risks. When speaking with a contractor, ask, “Do you recommend ice and water shield on my roof’s eaves and valleys based on local ice dam history?” and “Will the use of ice and water shield affect my shingle warranty or future inspections?” These questions ensure your roof remains well-protected without compromising manufacturer terms.