Grace Ice and Water Shield is the rubberized asphalt self adhered underlayment that most contractors treat as the reference product for eaves, valleys, and roof penetrations. This single brand review covers the full GCP line (standard, HT, Select, and Ultra), verified published specifications, where each version fits, how it installs, and how it stacks up against GAF WeatherWatch and StormGuard. Figures here come from GCP data sheets and aggregated retailer and contractor sentiment, not independent lab testing by The Roofing Brief.
Looking to compare brands head to head instead of going deep on one? See our best ice and water shield roundup, which ranks Grace against GAF and Owens Corning. This page stays on Grace and goes deeper.
Is Grace Ice and Water Shield worth it?
For the eaves, valleys, and penetrations where a leak actually starts, Grace Ice and Water Shield is worth the premium for most shingle jobs. It is the original rubberized asphalt membrane, it self seals tightly around fasteners, and its 40 mil body and granular surface give it a proven multi decade track record. The main tradeoffs are price and a sticky, unforgiving install in warm weather.
The Roofing Brief verdict: Buy for shingle eaves and valleys. Step up to the HT version for metal, tile, or hot climates. If budget is tight across a full deck, Grace on the critical zones plus a synthetic field underlayment is the common contractor split.
Grace Ice and Water Shield specs at a glance
Grace Ice and Water Shield is a 40 mil (1.02 mm) membrane built from rubberized asphalt bonded to a cross laminated polyethylene film, supplied in 36 inch wide rolls. The standard granular product is rated for continuous service to 180F and up to 30 days of UV exposure, and it meets ASTM D1970, the standard reference for self adhered ice barrier membranes.
| Spec | Grace Ice and Water Shield (standard) |
|---|---|
| Membrane thickness | 40 mil (1.02 mm), per ASTM D3767 Method A |
| Roll width | 36 in (3 ft); strips also in 6, 9, 12, 18 in |
| Coverage per roll | About 200 sq ft (66.6 ft) or 225 sq ft (75 ft) |
| Service temperature | 25F to 180F |
| Application temperature | Air, deck, and membrane at 40F or higher recommended |
| UV exposure limit | 30 days |
| Surface | Granular, aids shingle adhesion |
| Standards | ASTM D1970; low temp flexibility unaffected at minus 20F |
| Permeance | 0.05 perms max (vapor tight) |
| Release | Split back ripcord for one person alignment |
| Typical price | Roughly 90 to 120 dollars per square; near 245 dollars per 225 sq ft roll at retail (varies by market and date) |
Pricing is conditional and moves with supplier, region, and season. Treat these as order of magnitude figures, not a live quote.
The Grace product line: standard vs HT vs Select vs Ultra
GCP sells Grace Ice and Water Shield as a family, not one product. The split that matters most is standard granular for shingles versus HT for metal, tile, and hot climates. Select is the value film surfaced option, and Ultra is the premium high performance film membrane. Matching the version to the roof covering and temperature is the single most common spec mistake this review sees.
| Product | Surface | Service temp / UV | Best use |
|---|---|---|---|
| Ice and Water Shield (standard) | Granular | To 180F / 30 days | Asphalt shingle eaves and valleys |
| Ice and Water Shield HT | Poly film, UV barrier | Thermal stability to 260F / 120 days | Metal, tile, high slope, hot climates |
| Select (Select HT) | Film | HT variant rated for high heat | Value option, broader field use |
| Ultra | Premium film | High performance, extended exposure | Demanding metal and specialty assemblies |
The practical rule: if a metal panel or dark tile will sit over the membrane, or the roof bakes in southern sun, use HT or Ultra. The granular standard product can exceed its service window under metal in hot climates. For the full field of a metal roof, see our guide to metal roof underlayment options.
Where and how to use Grace Ice and Water Shield
Grace goes where water pools, backs up, or gets driven sideways: the eaves in ice dam country, every valley, and around chimneys, skylights, vents, and wall intersections. In cold climates the International Residential Code requires an ice barrier at the eaves, and Grace is a standard way to meet it.
- Eaves: Run the membrane from the edge to at least 24 inches inside the exterior wall line, the IRC R905.1.2 minimum. Verify the exact coverage in our ice dam membrane code guide.
- Valleys: Center a full 36 inch width in every valley before shingles.
- Penetrations: Wrap chimneys, skylights, plumbing boots, and sidewalls; the self seal around fasteners is the whole point.
- Low slope tie ins: Porches and low pitch sections where wind driven rain is a risk.
For a wider look at self adhered products and coverage math, see our ice and water shield cost and coverage guide.
Installation: getting Grace down clean
Grace installs without heat or primer on a clean, dry, 40F or warmer deck, but the aggressive tack means alignment matters before the film contacts the wood. The split back ripcord lets one person set a straight line, then peel each half. Once the adhesive touches the deck it does not reposition, so patience beats speed.
- Confirm the deck is clean, dry, and at 40F or above. Sweep off dust and debris.
- Snap a chalk line for the first course so the roll runs straight.
- Cut a manageable length. Shorter pieces are easier to control solo than a full roll.
- Align the roll to the line, then pull the ripcord to split the release film.
- Peel the lower half, press it down, then peel and set the upper half, working out wrinkles.
- Lap courses per the data sheet and roll or hand press all seams for full contact.
- Cover promptly. Do not exceed the 30 day UV window on the standard product.
Warm weather is the enemy of a neat install: above about 70F the granular standard membrane gets very sticky and can wrinkle or fold on itself. Reviews repeatedly flag two failure modes, a missing or broken ripcord and backing that sticks to itself, so many crews run it two people in heat.
Grace vs GAF WeatherWatch and StormGuard
The closest competitors are GAF WeatherWatch (granular, shingle only) and GAF StormGuard (smooth film, shingle and metal). Grace competes with both from a single line: the granular standard product answers WeatherWatch, and Grace HT or Ultra answers StormGuard on metal. Grace generally carries a price premium and the strongest reputation for self sealing.
| Product | Surface | Roofs | High temp | Roll coverage |
|---|---|---|---|---|
| Grace Ice and Water Shield | Granular | Shingle | To 180F | 200 or 225 sq ft |
| Grace HT | Poly film | Metal, tile, shingle | To 260F | 200 or 225 sq ft |
| GAF WeatherWatch | Granular | Shingle only | Standard | 1.5 sq (150 sq ft) |
| GAF StormGuard | Smooth film | Shingle and metal | To 250F | 2 sq (200 sq ft) |
Match by surface and roof type, not by brand loyalty. Granular products (Grace standard, GAF WeatherWatch) grip asphalt shingles; film products (Grace HT and Ultra, GAF StormGuard) suit metal. GAF products may also carry system warranty advantages when paired with a full GAF roof, which is worth weighing on a manufacturer system job.
Pros and cons
Grace Ice and Water Shield earns its reputation on sealing performance and consistency, and loses points on price and warm weather handling. Here is the honest split from published specs and aggregated contractor and homeowner feedback.
- Pros: Original rubberized asphalt with a long track record; tight self seal around nails; granular surface aids shingle bond; meets ASTM D1970; full line covers shingle through metal; ripcord aids solo alignment.
- Cons: Highest cost among common ice and water shields; very sticky and wrinkle prone above about 70F; unforgiving once set; 30 day UV limit on the standard product; reports of missing or broken ripcords.
Warranty and what to verify
GCP publishes limited product warranties for Grace Ice and Water Shield, and terms vary by product, assembly, and whether the roof is registered as a system. Coverage often depends on installation to the data sheet and pairing with compatible products. Confirm the current warranty document for the exact version you buy rather than relying on a headline number.
Because warranty and code coverage both hinge on correct installation, budget matters: for how Grace fits a broader self adhered strategy, see our peel and stick underlayment guide.
Frequently asked questions
Is Grace Ice and Water Shield worth it?
For eaves, valleys, and penetrations on a shingle roof, yes. Grace Ice and Water Shield is the original rubberized asphalt membrane, seals tightly around fasteners, and has a multi decade track record. The premium price is easiest to justify on the critical leak zones. Many crews run Grace there and a cheaper synthetic across the open field to control cost.
What is the difference between Grace Ice and Water Shield and HT?
The standard product has a granular surface, a 180F service rating, and a 30 day UV limit, which suits asphalt shingles. Grace HT has a poly film surface, thermal stability to 260F, and a 120 day UV window, which suits metal panels, tile, high slope, and hot climates where the standard membrane can exceed its temperature range.
How long can Grace Ice and Water Shield be exposed before covering?
The standard granular Grace Ice and Water Shield is rated for up to 30 days of UV exposure before the roof covering must go on. Grace HT extends that to 120 days thanks to its UV barrier film. Exceeding the window can degrade the membrane, so plan the sequence so shingles or panels follow within the limit.
Can you use Grace Ice and Water Shield under metal roofing?
Use Grace HT or Ultra, not the standard granular product, under metal. Metal panels transmit heat that can push a membrane past the standard 180F rating, and Grace HT is rated to 260F for exactly this reason. The film surface also suits direct contact with metal better than a granular face.
How much does Grace Ice and Water Shield cost?
Grace Ice and Water Shield typically runs about 90 to 120 dollars per square (100 sq ft), and a 225 sq ft roll has been priced near 245 dollars at retail. It is generally the most expensive common ice and water shield. Pricing varies by supplier, region, and season, so confirm a live quote before ordering.
Grace vs GAF WeatherWatch, which is better?
Both are granular ice and water shields for asphalt shingles. Grace is the older reference product with a strong self sealing reputation and usually a higher price; GAF WeatherWatch is a common, often cheaper alternative that may bring system warranty benefits on a full GAF roof. For metal, compare Grace HT to GAF StormGuard instead, since both use film surfaces.
Reviewed by The Roofing Brief Team. Last reviewed August 2026.