The best ice and water shield for most roofs in 2026 is Grace Ice & Water Shield from GCP Applied Technologies, the original rubberized-asphalt membrane that self-seals around nails and sets the standard other leak barriers are measured against. The right pick depends on your roof, though: metal panels, steep slopes, and long exposure windows each favor a different membrane. Below is a ranked comparison of the leading brands, what each one is best for, and how to match a product to your deck.
An ice and water shield (also called a leak barrier or self-adhered underlayment) is a peel-and-stick membrane installed at eaves, valleys, and penetrations to stop water driven uphill by ice dams and wind. It matters because the standard roofing felt underlayment shingles sit on does not seal around fasteners or block ice-dam backup. In cold-climate counties, the IRC (Section R905.1.2) requires an ice barrier extending at least 24 inches inside the exterior wall line for asphalt shingles, metal shingles, slate, and wood roofs.
How we picked the best ice and water shield
We ranked these membranes on published manufacturer specifications, the ASTM D1970 standard that governs self-adhered ice barriers, temperature and UV-exposure ratings, typical installed price, and aggregated contractor and homeowner sentiment. This is a specifications-and-standards review, not a hands-on lab test. Prices are indicative ranges that vary by region, supplier, and roll size, so treat them as planning figures rather than quotes.
Three specs decide most real jobs. Surface type (granular, smooth film, or high-heat) controls where a membrane can go. Temperature rating determines whether it can sit under hot metal panels without the adhesive migrating. UV-exposure window sets how long it can stay uncovered before shingles or panels go on. We weighted those first, then price.
Best ice and water shield brands compared (2026)
The table below compares the leading ice and water shield products on surface, temperature rating, indicative price per square (100 square feet), and the job each one suits best. Ratings reflect published specs and standards, not proprietary testing.
| Product | Type | Surface | Max temp* | Price / square* | Best for |
|---|---|---|---|---|---|
| Grace Ice & Water Shield (GCP) | Rubberized asphalt | Granular | ~180°F | ~$90–$120 | Overall pick: eaves and valleys on shingle roofs |
| Grace Ultra (GCP) | Butyl | High-heat film | ~300°F | ~$120–$160 | Metal roofs and extreme heat |
| GAF StormGuard | Rubberized asphalt | Smooth film | ~250°F | ~$75–$100 | Mixed shingle and metal, GAF system warranty |
| Owens Corning Titanium PSU30 | Synthetic (polymer) | Non-slip film | ~240°F | ~$85–$120 | Walkability and long UV exposure |
| GAF WeatherWatch | Rubberized asphalt | Granular | ~180°F | ~$50–$70 | Budget granular for shingle eaves |
| Owens Corning WeatherLock | Rubberized asphalt | Granular / mat | ~180°F | ~$55–$80 | Pairing with an Owens Corning shingle system |
*Temperature ratings and prices are from published manufacturer and supplier data and vary by roll size, region, and retailer. Verify current figures before you buy.
1. Grace Ice & Water Shield: best overall (top pick)
Grace Ice & Water Shield is our top overall pick because it is the original rubberized-asphalt leak barrier and remains the reference product contractors compare everything else against. Its granular surface grips shingles, and the adhesive self-seals tightly around roofing nails, which is the core job of any ice barrier. A standard roll covers about 225 square feet (36 inches by 75 feet) and it passes ASTM D1970.
Its ceiling is heat. Rated to roughly 180°F, standard Grace is built for asphalt-shingle eaves and valleys, not for direct contact under hot metal panels. For metal, GCP sells Grace HT (rated to about 260°F) and the premium Grace Ultra. Indicative pricing runs about $90 to $120 per square, above the budget granular options but in line with its track record.
2. Grace Ultra: best for metal roofs and extreme heat
Grace Ultra is the strongest choice for metal roofs and high-heat assemblies because its 100% butyl-rubber adhesive stays stable at temperatures up to roughly 300°F, the highest rating in this group. Butyl does not soften and migrate the way rubberized asphalt can under a hot standing-seam panel, which is why it commands a premium.
Expect indicative pricing around $120 to $160 per square, the top of the range here. For a shingle roof in a mild climate that heat headroom is overkill, so Ultra earns its place specifically on metal, low-slope, and hot-climate roofs where a standard membrane would be pushed past its rating.
3. GAF StormGuard: best for mixed roofs and system warranty
GAF StormGuard is the best pick when you want one membrane for both shingle and metal work or you are building a warranted GAF system. Its smooth film surface is rated to about 250°F and tolerates up to six months of UV exposure before covering, far longer than granular felt-based barriers. That exposure window helps on staged jobs and phased tear-offs.
Indicative pricing lands near $75 to $100 per square. As part of a full GAF roof, StormGuard also counts toward the manufacturer’s enhanced system warranties when installed by a certified contractor, which can matter more than the membrane price alone.
4. Owens Corning Titanium PSU30: best for walkability and long exposure
Titanium PSU30 is the standout for crews who value footing and a long exposure window, because it is a synthetic polymer membrane with a Sure-Foot non-slip surface and up to 180 days of rated UV exposure. It is rated to about 240°F under metal and carries a lifetime limited warranty. A roll covers roughly 216 square feet (36 inches by 72 feet).
Being synthetic rather than asphalt-based, it is lighter (around 51 pounds per roll) and lies flatter in cold weather. Indicative pricing runs about $85 to $120 per square. It suits steep-slope work where grip matters and re-roofs where the deck may sit exposed for weeks.
5. GAF WeatherWatch: best budget granular barrier
GAF WeatherWatch is the value pick for standard asphalt-shingle eaves and valleys, priced around $50 to $70 per square, the lowest here. Its granular surface adheres well to shingles and resists UV during normal installation, and it is engineered specifically for shingle roofs rather than metal.
The trade-offs are a lower temperature rating (about 180°F) and a short UV-exposure window, typically around 30 days, so it should be covered promptly. For a straightforward shingle re-roof in a moderate climate, it delivers code-compliant eave and valley protection at the lowest material cost.
6. Owens Corning WeatherLock: best for an Owens Corning system
Owens Corning WeatherLock is the logical leak barrier when the rest of the roof is an Owens Corning system, sold in granular (WeatherLock G), mat, and flexible (WeatherLock Flex) versions. The granular grades handle eaves and valleys on shingle, wood-shake, and slate assemblies, while Flex bends easily around pipes, chimneys, and skylights.
Indicative pricing runs about $55 to $80 per square depending on grade, with a 200-square-foot roll common at big-box retailers. Choosing WeatherLock keeps the underlayment, shingle, and warranty inside one manufacturer’s system, which some Owens Corning warranties reward.
Which ice and water shield should you buy?
Match the membrane to the roof surface and climate, then to price. Use this decision guide to narrow the field quickly before you price rolls.
- Asphalt shingle, moderate climate: Grace Ice & Water Shield for the safest track record, or GAF WeatherWatch and Owens Corning WeatherLock to cut material cost.
- Metal roof or hot climate: Grace Ultra or Grace HT for butyl-grade heat resistance; GAF StormGuard as a mid-priced film option.
- Long exposure or steep, walked-on slopes: Owens Corning Titanium PSU30 for its non-slip surface and 180-day UV window.
- Warranted manufacturer system: match the membrane to your shingle brand (GAF StormGuard or WeatherWatch, Owens Corning WeatherLock) so it counts toward system coverage.
Whatever you choose, install it where water actually backs up: eaves, valleys, and around every penetration. Pair it with correct eave and gutter flashing so the membrane and metal shed water together. Getting this layer right is one of the cheapest ways to prevent the interior water damage an ice dam can cause.
Do you need ice and water shield everywhere?
No. Full-deck ice and water shield is rarely required and often not recommended, because a fully sealed asphalt deck cannot dry outward and can trap moisture. Code and best practice call for it at vulnerable zones, not the whole roof. The IRC ice-barrier rule targets eaves in cold-climate areas, and manufacturers specify valleys and penetrations as the other priority spots.
On low-slope sections, around skylights, and in valleys, the membrane earns its cost. Across large open field areas of a steep shingle roof in a mild climate, a synthetic or felt underlayment usually does the job. If you are weighing a full DIY roof replacement, confirm your local amendments, since some jurisdictions and post-storm-damage rebuilds expand the requirement.
Frequently asked questions
What is the best ice and water shield brand?
Grace Ice & Water Shield from GCP Applied Technologies is widely regarded as the best overall ice and water shield, since it is the original rubberized-asphalt membrane and the benchmark others are measured against. For metal roofs, Grace Ultra rates higher on heat resistance at up to about 300°F. The best brand for you depends on roof surface, climate, and budget rather than one universal winner.
How much does ice and water shield cost?
Ice and water shield material typically costs about $50 to $160 per square (100 square feet) depending on brand and grade, based on published supplier pricing. Budget granular barriers like GAF WeatherWatch sit near the low end, while premium butyl membranes like Grace Ultra sit at the top. Installed cost adds labor and varies by region, roof complexity, and how much of the roof the barrier covers.
Is Grace or GAF ice and water shield better?
Grace Ice & Water Shield generally holds the edge on reputation as the original rubberized-asphalt barrier, while GAF StormGuard offers a higher UV-exposure window (up to six months) and counts toward GAF system warranties. For a warranted GAF roof, GAF’s own barriers often make more sense. For a standalone premium leak barrier, many contractors still default to Grace.
Does code require ice and water shield?
In cold-climate areas with a history of ice dams, the IRC (Section R905.1.2) requires an ice barrier at eaves extending at least 24 inches inside the exterior wall line for asphalt shingles, metal shingles, slate, and wood roofs. Requirements vary by jurisdiction and local amendments, so confirm your area’s adopted code. Warm-climate roofs may not require it, though valleys and penetrations still benefit.
Can you use ice and water shield under a metal roof?
Yes, but use a high-temperature grade. Standard rubberized-asphalt barriers rated near 180°F can soften under hot metal panels, so choose a high-heat membrane such as Grace Ultra (about 300°F), Grace HT (about 260°F), GAF StormGuard (about 250°F), or Titanium PSU30 (about 240°F). Always confirm the membrane’s rating against the panel manufacturer’s underlayment requirements before installing.
How long can ice and water shield be left exposed?
Exposure windows vary widely by product. Granular felt-based barriers like GAF WeatherWatch are typically rated for about 30 days of UV exposure, while smooth-film and synthetic membranes last far longer: GAF StormGuard up to about six months and Owens Corning Titanium PSU30 up to 180 days. Cover any membrane within its rated window to avoid adhesive and surface degradation.
Reviewed by The Roofing Brief Team. Last reviewed July 2026.