Facts checked September 22, 2026
Every major shingle maker sells its own ice barrier, and on paper they look alike: all of the products below meet ASTM D1970, the standard for self-adhering underlayment used as ice dam protection. The differences that matter are in the details. Is the top surface granular or film? Is it rated for the heat under a metal roof? How cold can it be when it goes down? Does it belong to the same system as your shingles?
That last question matters to us. We're GAF Certified Plus and CertainTeed ShingleMaster, and both companies sell their leak barriers as part of a roof system. CertainTeed, for example, states that WinterGuard carries a limited warranty of up to 50 years, matching the shingles above it. If you're buying a manufacturer's system warranty, ask which underlayment it calls for, and match the membrane to the shingle brand.
This page is about the membrane under the roof. If you're still choosing the roof itself, see our guide to the best roofing material for Michigan.
What We Compared
ASTM D1970 and a Code Report
Every pick meets ASTM D1970. Most also hold an ICC-ES evaluation report that recognizes the membrane as a code ice barrier. We note which ones don't list one.
Surface: Granular or Film
Sand and granule surfaces give traction under shingles. Smooth film surfaces won't scratch the underside of metal panels.
High-Temperature Rating
Metal roofs run hot. High-temperature membranes are rated to 250°F or more; some standard membranes list no rating at all.
Cold-Weather Application
Most of these want 40°F to 45°F or warmer and a dry deck to bond. That matters for a November or March roof in West Michigan.
Exposure Window
How long the membrane can sit uncovered, from 30 days to six months. It matters when weather stretches a job out.
System Fit
A membrane from your shingle maker keeps the roof within one manufacturer's system, which can matter for its warranty.
8 Ice and Water Shield Membranes for Michigan Roofs
1. GAF WeatherWatch
Best for: Asphalt shingle roofs built as a GAF system
WeatherWatch is GAF's mineral-surfaced, fiberglass-reinforced leak barrier for asphalt shingles. The granular top gives a roofer footing on a cold, steep deck, and a split-back release film lets it be positioned one half at a time.
GAF describes it as compatible with asphalt shingle roof systems and points to StormGuard for metal. Its evaluation report puts it at a nominal 73 mil, the thickest GAF membrane on this list.
- Mineral surface, fiberglass reinforced, nominally 73 mil (ICC-ES ESR-1322)
- Rolls of 150 or 200 sq ft, 36 in wide
- Apply between 45°F and 120°F on a dry deck
- Can stay exposed up to 60 days if necessary
2. GAF StormGuard
Best for: GAF roofs over metal panels, or a shingle roof where a smooth film surface is wanted
StormGuard is GAF's film-surfaced leak barrier: a blue, patterned synthetic top over fiberglass reinforcement. GAF says it gives wet and dry traction and runs cooler to work on than typical black underlayments.
Its high-temperature compound is rated to 250°F, and GAF says it can go under asphalt shingles and most metal roofing systems. For copper or zinc, GAF asks installers to contact its technical support first.
- Film surface, nominally 55 mil (ICC-ES ESR-1322)
- High-temperature rating 250°F
- Apply between 45°F and 120°F on a dry deck
- Can stay uncovered up to 90 days
3. CertainTeed WinterGuard Sand and Granular
Best for: CertainTeed shingle roofs, especially low-slope sections down to 2:12
WinterGuard is CertainTeed's long-running ice barrier: SBS-modified asphalt over reinforcement, topped with sand or granules for traction, with a split release film. CertainTeed lists a minimum slope of 2:12 and up to six months of exposure, the longest window among the granular membranes here.
CertainTeed is candid about cold weather. Its applicator's manual says WinterGuard temporarily loses most of its tack below 40°F and should go down in fair weather above that, and that nailing it in place in cold weather cannot provide ice dam protection. It also won't stick to a wet or frozen deck.
- Typical thickness 60 mil (Sand, Granular); 55 mil for Sand X
- ICC-ES ESR-1492 (Sand and Granular)
- Up to 6 months of exposure; minimum slope 2:12
- Limited warranty up to 50 years, matching the shingles above
4. CertainTeed WinterGuard HT X
Best for: Metal roofs, when you want a CertainTeed membrane underneath
HT X is CertainTeed's high-tack, high-temperature WinterGuard. CertainTeed says it's formulated to resist the heat under metal roofs and has a tough, tear-resistant film top that won't scratch metal roofing.
It goes down a little colder than the GAF membranes, at 40°F and up, and can sit exposed for 180 days.
- Film surface, 40 mil, rated to 250°F
- Apply between 40°F and 120°F on a dry deck
- Up to 180 days of exposure
- Code compliance: Intertek CCRR 0636, ASTM D1970
5. CertainTeed VYCOR Ice & Water Shield (formerly Grace)
Best for: Anyone who wants the membrane once sold as Grace, now made by CertainTeed
Grace Ice & Water Shield, a name many homeowners still ask for, came from GCP Applied Technologies, which Saint-Gobain acquired in a deal that closed on September 27, 2022; GCP's North American building materials business merged into CertainTeed. The product is now sold as CertainTeed VYCOR Ice & Water Shield, and CertainTeed says it has a 45-plus-year track record.
Standard VYCOR is rubberized asphalt with a slip-resistant, cross-laminated polyethylene film. VYCOR Ice & Water Shield HT is the high-temperature version, rated to 260°F and allowed up to 120 days of exposure, which suits metal roofs.
- 40 mil, film surface (ICC-ES ESR-1677, both versions)
- Apply at 40°F or warmer
- HT version rated to 260°F
- Standard version: not for copper, COR-TEN or zinc roofs at high altitude
Visit CertainTeed VYCOR Ice & Water Shield (formerly Grace)'s website →
6. IKO ArmourGard and StormShield
Best for: IKO shingle roofs, and very low slopes that need full coverage
IKO makes two mineral-surfaced, fiberglass-reinforced ice and water protectors. ArmourGard is the heavier one at 55 mil and sand surfaced for slip resistance. StormShield is 43 mil. IKO describes the job plainly: protection against the water an ice dam forces beneath the shingles.
IKO's instructions go beyond the code minimum on shallow roofs. On slopes from 2:12 to 4:12, IKO calls for covering the entire roof area with the membrane.
- ArmourGard 55 mil; StormShield 43 mil
- 195 sq ft rolls, 65 ft x 36 in
- StormShield: up to 30 days of UV exposure in the US
- No ICC-ES report or temperature rating on the data sheets
7. Atlas WeatherMaster Ice & Water 200
Best for: Atlas shingle roofs
Atlas's shingle ice barrier is fiberglass-mat reinforced, SBS-modified asphalt with a granular surface. Atlas lists high-temperature stability of 240°F and a 45-day exposure window, and its data sheet calls for running it at least 24 inches beyond the interior wall line.
The WeatherMaster line also includes HP-Granular, HP-Flex and a Tile version. Atlas wants ambient and deck temperatures of 45°F or higher, and says priming may be needed at 45°F.
- Granular surface, 40 mil minimum
- High-temperature stability 240°F
- 45-day exposure window
- Florida and Miami-Dade listed; no ICC-ES report found
8. Polyglass Polystick MTS Plus
Best for: Metal roofs where the membrane may sit exposed for months
Polystick MTS Plus is Polyglass's SBS-modified, film-surfaced underlayment, and the heat rating is the highest on this list at 265°F. It can be left exposed for 180 days.
For shingles, Polyglass makes Polystick IR-Xe, an aggregate-surfaced, fiberglass-reinforced ice and water underlayment with up to 90 days of exposure.
- Film surface, 60 mil nominal
- Temperature resistant to 265°F
- Apply when air, deck and membrane are 40°F and rising
- ICC-ES ESR-1697
Ice Barrier Membranes Side by Side
| Membrane | Surface | Thickness | Heat rating | Apply at or above | Exposure | Code report |
|---|---|---|---|---|---|---|
| GAF WeatherWatch | Mineral | 73 mil (ESR) | Not stated | 45°F | 60 days | ESR-1322 |
| GAF StormGuard | Film | 55 mil (ESR) | 250°F | 45°F | 90 days | ESR-1322 |
| CertainTeed WinterGuard Sand / Granular | Sand or granules | 60 mil (TDS) | Not stated | 40°F | 6 months | ESR-1492 |
| CertainTeed WinterGuard HT X | Film | 40 mil | 250°F | 40°F | 180 days | Intertek CCRR 0636 |
| CertainTeed VYCOR Ice & Water Shield | Film | 40 mil | Not stated | 40°F | Cover within 90 days | ESR-1677 |
| CertainTeed VYCOR Ice & Water Shield HT | Film | 40 mil | 260°F | 40°F | 120 days | ESR-1677 |
| IKO ArmourGard | Sand / mineral | 55 mil | Not stated | Not stated | Not stated | None listed |
| IKO StormShield | Mineral | 43 mil | Not stated | Not stated | 30 days (US) | None listed |
| Atlas WeatherMaster Ice & Water 200 | Granular | 40 mil min. | 240°F | 45°F | 45 days | None found |
| Polyglass Polystick MTS Plus | Film | 60 mil | 265°F | 40°F | 180 days | ESR-1697 |
From each manufacturer's data sheet or installation instructions and the ICC-ES reports, checked 22 September 2026. "Not stated" means the documents we checked don't give the figure. Where a data sheet and an evaluation report give different thicknesses, the source is marked (ESR or TDS).
What Michigan Code Requires at the Eaves
Michigan builds to the Michigan Residential Code, which is still the 2015-based edition. A 2021-based update was due to take effect in August 2025, but a Michigan Court of Claims order in July 2025 blocked it, and the state's building codes bureau says the 2015 code stays in effect while that order stands. The draft update keeps the same ice barrier wording anyway.
The code's climate table answers "Yes" for ice barrier underlayment statewide. In practice that means every new roof on a Michigan house needs one. Section R905.1.2 sets the minimum:
- Material: at least two layers of underlayment cemented together, or a self-adhering polymer-modified bitumen sheet, which is what every membrane on this list is
- Coverage: from the lowest edge of every roof surface to a point at least 24 inches inside the exterior wall line
- Steep roofs: on slopes of 8:12 or steeper, it must also run at least 36 inches up the slope from the eave
- Exception: detached accessory structures with no conditioned floor area, such as an unheated detached garage or shed
The Membrane Doesn't Stop Ice Dams
Ice and water shield keeps backed-up water off the deck. It doesn't stop the dam from forming. The manufacturers say so themselves: GAF's technical bulletin on ice dams warns that extreme ice dam conditions can still cause leaks when water backs up over the protection and the flashings, and names ventilation as the next line of defense. CertainTeed's homeowner guide lists insulation, ventilation and waterproofing underlayment, and says all three work together. Its VYCOR data sheet says the membrane should be used with roof designs that minimize ice dams.
Code minimum is also just that. CertainTeed says that in areas of severe icing, WinterGuard should reach at least the highest water level expected behind an ice dam, and IKO says the same for its membranes. On a deep overhang or a low pitch, that can be well above 24 inches past the wall. We run ice and water shield at the eaves on every replacement, but if your house gets dams every winter, the fix is in the attic.
Why Ice Dams Form
Heat escaping into the attic melts snow on the upper roof, and the water refreezes at the cold eave. Air sealing, insulation and balanced ventilation are the lasting fix.
Ice Dams on Your RoofProducts That Help
Our honest ranking of ice dam fixes, from air sealing to roof rakes and heat cable, and what each one really does.
Best Ice Dam Prevention ProductsFour Questions About the Underlayment in Your Bid
01. Which membrane, by name?
"Ice and water shield" on an estimate can mean any of these products. Ask for the brand and product, and whether it matches the shingle maker's system.
02. How far up the roof?
Code says at least 24 inches inside the exterior wall line, plus 36 inches up the slope on 8:12 and steeper roofs. Ask whether your overhang or pitch calls for more, and whether valleys and other weak spots get it too.
03. Is it rated for metal?
Under a metal roof, ask for a high-temperature, film-surfaced membrane such as GAF StormGuard, WinterGuard HT X or VYCOR HT.
04. What if it's cold on install day?
Most of these want 40°F to 45°F and a dry deck to bond. Ask how the crew handles a cold morning, because a membrane that isn't bonded isn't protecting anything.
Not Sure What's Under Your Shingles?
Our free inspection covers the roof, the attic and the deck, with photos and a written report. If your ice barrier stops short or your attic is feeding ice dams, we'll show you, and we'll tell you when you don't need a new roof yet.
Schedule a Free Roof InspectionMore Roofing Resources
Roof Replacement
Full tear-off, new flashing, corrected ventilation and ice and water shield at the eaves.
Learn MoreIce Dams on Your Roof
Why ice dams form in West Michigan and how to stop them coming back.
Learn MoreBest Roof Replacement Companies in Grand Rapids
Our roundup of Grand Rapids roofers for full replacements.
Learn MoreBest Roofing Companies in Grand Rapids
Seven Grand Rapids roofers and what each one is best for.
Learn MoreBest Ice and Water Shield Underlayments for Michigan Roofs: FAQ
Is ice and water shield required in Michigan?
Yes. The Michigan Residential Code's climate table requires an ice barrier statewide. It has to run from the eave to at least 24 inches inside the exterior wall line, and on roofs of 8:12 or steeper, at least 36 inches up the slope from the eave. Detached accessory buildings with no conditioned space are exempt.
Does ice and water shield prevent ice dams?
No. It keeps water that backs up behind an ice dam from reaching the deck. The dam itself comes from heat escaping into the attic, so air sealing, insulation and ventilation are what stop it. GAF and CertainTeed both say the membrane works alongside those fixes, not instead of them.
What's the best ice and water shield for a metal roof?
Use a high-temperature, film-surfaced membrane. GAF StormGuard and CertainTeed WinterGuard HT X are rated to 250°F, VYCOR Ice & Water Shield HT to 260°F and Polyglass Polystick MTS Plus to 265°F. The film surface also won't scratch the underside of the panels. GAF WeatherWatch is sold for asphalt shingle roofs.
Is Grace Ice & Water Shield still made?
Yes, under a new name. Saint-Gobain bought GCP Applied Technologies, Grace Ice & Water Shield's maker, in a deal that closed in September 2022, and GCP's North American business merged into CertainTeed. The product is now CertainTeed VYCOR Ice & Water Shield, with a high-temperature HT version.
Can ice and water shield be installed in winter?
Only with care. The manufacturers want 40°F to 45°F or warmer and a dry deck. CertainTeed says WinterGuard loses most of its tack below 40°F and won't stick to a wet or frozen surface. On a cold-weather job, ask your roofer how they'll get the membrane to bond.
Should I use the same brand as my shingles?
It's the safest choice if you want a manufacturer's system warranty. GAF and CertainTeed both sell their leak barriers as part of a roof system, and CertainTeed states WinterGuard's limited warranty runs up to 50 years, matching the shingles above it. Ask your roofer which underlayment the warranty you're buying calls for.
What This Page Cites
- GAF: StormGuard data sheet (RESUL116) and installation instructions (RESUL192); WeatherWatch sell sheet (RESUL103), product page and installation instructions; Technical Advisory Bulletin TAB-R-116, Ice Dams: Cause and Preventative Measures.
- ICC-ES evaluation reports ESR-1322 (GAF), ESR-1492 (CertainTeed WinterGuard), ESR-1677 (CertainTeed VYCOR) and ESR-1697 (Polyglass), icc-es.org and certainteed.widen.net.
- CertainTeed: WinterGuard Granular/Sand/Sand X technical data sheet; WinterGuard HT X technical data sheet and product page; WinterGuard sell sheet and brochure; Shingle Applicator's Manual, chapter 5; VYCOR Ice & Water Shield and VYCOR HT technical data sheets and product page; homeowner ice dam guide (00-00-3962).
- GCP Applied Technologies press release on the Saint-Gobain acquisition (SEC filing, December 2021); Chryso, "GCP's acquisition by Saint-Gobain closes" (September 2022).
- IKO: StormShield and ArmourGard technical data sheets; ArmourGard/StormShield application instructions; bulletin R-11; "What Is an Ice and Water Protector?" (iko.com).
- Atlas Roofing: WeatherMaster Ice & Water 200 product page and data sheet; WeatherMaster HP-Flex and Tile data sheets.
- Polyglass: Polystick IR-Xe product page; Polystick MTS Plus product data sheet.
- Michigan Residential Code 2015, Section R905.1.2 and Table R301.2(1), via UpCodes; Michigan LARA Bureau of Construction Codes, currently open rules page and 2021 code injunction notice.
- All sources checked 22 September 2026.