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If you have ever had a roofer mention “Grace” during an estimate, they were not talking about a person. They were referring to one of the most trusted names in roofing protection. Grace Ice & Water Shield, now manufactured by GCP Applied Technologies, is a self-adhered rubberized asphalt membrane designed to keep water out of your home. It is applied directly to the roof deck before shingles or other coverings go on. Think of it as your roof’s last line of defense when everything else fails. When wind-driven rain pushes past your shingles or ice dams force water upward, this ice and water shield roofing layer is what stands between your home and serious water damage.
What Is Grace for Roofing?
Grace is a premium roof underlayment grace product that bonds directly to a wooden roof deck without the need for mechanical fasteners during application. It is made from two waterproofing materials: a rubberized asphalt adhesive and a slip-resistant polyethylene film. What makes it different from standard felt paper is the way it seals. When a roofing nail or screw penetrates the membrane, the rubberized asphalt actually wraps around the fastener and creates a watertight seal.
This self-sealing property is what sets Grace apart from traditional underlayments. Felt paper can tear, degrade in UV light, and lose its protective qualities in as little as 10 to 15 years. Grace products, on the other hand, are engineered to resist cracking, drying out, and rot. They maintain their integrity for the life of the roof covering above them.
Where Is Grace Ice & Water Shield Installed?
Grace is not meant to cover every square inch of your roof in most cases. It is strategically placed in the areas most vulnerable to water intrusion. These high-risk zones include eaves, valleys, around chimneys, near skylights, and along any roof penetration where flashing meets the deck.
In cold climates, building codes often require ice and water shield roofing along the eaves to protect against ice dams. Ice dams form when heat from the attic melts snow on the upper portion of the roof. That water runs down and refreezes at the colder eaves, creating a ridge of ice that traps water underneath shingles. Without a proper membrane in place, that trapped water seeps into the roof deck and eventually into your ceilings and walls.
On low-slope roofs, contractors often apply Grace as a full-coverage underlayment because the risk of water pooling is significantly higher. It is compatible with asphalt shingles, slate, tile, cedar shakes, and standing seam metal roofing systems.
Which Type of Roof Underlayment Is Best?
Not all underlayments are created equal, and the best choice depends on your roof type, climate, and budget. There are three main categories: felt, synthetic, and rubberized asphalt (which includes Grace products).
| Underlayment Type | Material | Lifespan | Water Resistance | Best For |
|---|---|---|---|---|
| Felt (15 or 30 lb) | Asphalt-saturated paper | 10-15 years | Moderate | Budget-friendly projects |
| Synthetic | Polyethylene/polypropylene | 25-30 years | High | Most standard roofing jobs |
| Rubberized Asphalt (Grace) | Rubberized asphalt + poly film | 30+ years | Superior | High-risk areas, ice dams, valleys |
Felt is the most affordable option, but it degrades faster and is more prone to tearing during installation. Synthetic underlayment is lighter, more durable, and provides better UV resistance. Rubberized asphalt products like Grace deliver the highest level of waterproofing protection, especially in vulnerable areas.
I always recommend using a grace roofing membrane at minimum in valleys and along eaves, even if the rest of the roof uses synthetic underlayment. That combination gives you strong protection without blowing the budget.
The Different Grace Product Lines
Grace is not just one product. GCP Applied Technologies offers several versions designed for different roofing conditions.
Grace Ice & Water Shield is the original and most widely used version. It has been protecting roofs for over 45 years and remains the industry standard for ice dam and wind-driven rain protection. It features a Ripcord split-release system that makes installation faster, especially around detail areas like dormers and valleys.
Grace Select is a thinner, lighter alternative that meets code requirements for fastener sealability while offering easier handling on the job site. It is a good fit for standard residential applications where extreme conditions are not a primary concern.
Grace Ultra uses a 100% butyl adhesive formulation and delivers the highest thermal stability in the product line, up to 300 degrees Fahrenheit. This makes it ideal for use under metal roofing, copper, and zinc coverings. Grace Ice & Water Shield HT is another high-temperature option, rated to 260 degrees, and specifically designed for metal roof assemblies.
What Damages the Roof the Most?
Understanding what threatens your roof helps explain why products like Grace exist in the first place. The biggest enemies are wind, water, ice, and UV exposure. Wind lifts shingles and exposes the layers beneath. Rain exploits every gap, crack, and exposed nail head it can find. Ice dams trap water in places it was never meant to sit.
Hail is another major culprit. It strips away the protective granules on asphalt shingles, which accelerates aging and leaves the underlying material exposed to moisture. Even small hailstones, around three-quarters of an inch, can cause real damage when driven by strong winds.
Sun damage is often overlooked. Prolonged UV exposure makes roofing materials brittle over time. Shingles curl, crack, and lose their ability to shed water effectively. When your outer roofing layer is compromised, the quality of your underlayment becomes everything. A roof underlayment grace product can be the difference between a minor repair and a full interior water damage restoration.
What Are Signs I Need Underlayment?
Most homeowners do not think about their underlayment until a problem shows up inside the house. By then, the damage is usually more extensive than it appears. Here are the warning signs to watch for.
Water stains on ceilings or walls are the most obvious indicator. Brown or yellow discoloration, bubbling paint, or damp patches all suggest moisture has made it past your roofing layers. Musty odors in the attic, especially after rain, point to a failed or deteriorating underlayment. If you can safely access your attic with a flashlight, look for dark stains on the underside of the roof deck, visible mold, or wet insulation.
On the exterior, cracked, curled, or missing shingles often mean the underlayment below is also compromised. Granules piling up in your gutters signal that your shingles are nearing the end of their useful life. If your roof is over 15 to 20 years old, the original felt underlayment has likely degraded significantly. A professional inspection can confirm whether a targeted repair or a full underlayment replacement is needed.
Why Grace Matters for Long-Term Roof Performance
I have seen too many roofs where the homeowner invested in premium shingles but skipped on quality underlayment. That decision almost always catches up with them. The shingles are what you see, but the underlayment is what actually keeps water out when conditions get rough.
Grace products are designed to perform for the life of your roof covering. They resist fungus, bacteria, and the freeze-thaw cycles that destroy lesser materials. For homeowners considering slate or other long-lasting roofing materials, pairing them with a grace roofing membrane makes practical sense. If you are exploring premium roofing options, check out The Timeless Elegance of Slate Roofs: How Long They Last and Why for more insight on getting the most from your investment.
How to Choose the Right Grace Product for Your Roof
Selecting the right Grace product comes down to three factors: your climate, your roof covering material, and your roof’s pitch. If you live in a region with harsh winters and frequent freeze-thaw cycles, Grace Ice & Water Shield along eaves and valleys is a smart baseline. For metal or copper roofing, step up to Grace Ultra or Grace HT to handle the higher temperatures those materials generate.
Low-slope roofs benefit from full-coverage application because water moves more slowly and has more opportunity to find its way through seams. Steep-slope roofs may only need Grace in targeted high-risk zones. Either way, working with an experienced roofing contractor ensures the product is installed correctly and in the right locations. Proper overlap, clean deck surfaces, and the right temperature conditions during installation all affect long-term performance.
Final Thoughts on Grace in Roofing
Grace Ice & Water Shield is not just another roofing accessory. It is a critical component of a well-built roof system. Whether you are dealing with ice dams in a northern climate, wind-driven rain along the coast, or simply want the best protection available under your shingles, ice and water shield roofing delivers peace of mind that cheaper alternatives cannot match. Investing in quality underlayment today saves you from expensive repairs and headaches down the road.
