Grace Ice & Water Shield Roof Underlayment Prevents Costly Leaks

ice dam, ice and water shield

In the United States and beyond, extreme weather is the new normal. Construction and repairs must withstand wind-driven rain, snow, ice and everything else that Mother Nature brings. Therefore, it is critical to make sure your home is waterproofed properly to prevent damage and costly repairs.

Grace ICE & WATER SHIELD® self-adhered roofing underlayment is designed to protect your home from wind-driven rain and ice dams. It truly is insurance for your home, offering protection from water getting behind an ice dam and leaking into your house.

ice and water shield

Grace ICE & WATER SHIELD® underlayment, manufactured by GCP Applied Technologies, is the original and best-in-class self-adhered roof underlayment. It was invented 40 years ago and continues to provide premium leak protection, defending homes against wind-driven rain and ice dams.

Grace ICE & WATER SHIELD® underlayment is composed of a specially formulated layer of rubberized asphalt adhesive that enables a watertight bond to the roof deck. This lasting bond is critical to the protection of your roof from leaks. In addition to the bond to the roof deck, Grace ICE & WATER SHIELD® membrane provides a high quality seal around the thousands of fasteners used to attach the shingles to your roof, bringing peace of mind against costly roof repairs.

ice and water shield

In addition, Grace ICE & WATER SHIELD® offers superior watertight laps, which are critically important in keeping the roof dry and safe. It also features the Ripcord® split release on demand, allowing for easy detailing of leak-prone areas of the roof deck, such as valleys, chimneys and roof to wall transitions. This combination of benefits provides robust protection of the roof’s most vulnerable areas.

GCP’s roofing underlayments can be used in new construction, re-roofing, or on roof repairs. For metal roof protection, choose Grace ICE & WATER SHIELD® HT underlayment. It has the same superior performance as the original, but is specially formulated to meet the service temperature challenges inherent in metal roofing systems and insulated roofing assemblies.

With severe weather becoming more and more commonplace, homes must be able to handle all that is thrown their way. By installing Grace ICE & WATER SHIELD® self-adhered roofing underlayment on your roof, you add another layer of protection against leaks caused by extreme conditions and prevent costly damage and emotional stress. For more information or to locate a distributor nationwide, visit


  • What is an ice dam, and what dangers do they pose to my home?  An ice dam begins to form when warmed air in the attic space, or solar radiation, causes snow on the roof to melt. The water flows down the slope of the roof toward the eave where it re-freezes, because the eave overhangs unheated space. As the process continues, ice builds up at the eave forming a dam. Standing water becomes trapped behind the ice dam and can leak into the building at fastener penetrations, usually right over the exterior wall. The damage can be severe, as well as difficult and expensive to repair, not to mention the distress it will cause your family. In addition to water leakage, ice dams can severely damage roof coverings, gutters, and other roof components.
  • Well, what can I do to prevent ice dams?  Roofs which are designed with proper insulation, and adequately ventilated will help limit the formation of ice dams, by minimizing the heat transfer from the building interior to the air in the attic space and removing any warmed air efficiently. The combination of air sealing, insulation, and ventilation is critical. The first step is to limit the transfer of heat from inside the structure to the attic space.  This means sealing all air leaks between the attic and the living space, as well ensuring that any HVAC ducts located in the attic are well sealed.  In a ventilated attic, the ceiling should also be generously insulated to limit heat loss to the attic.  The attic insulation should not block or interfere with the function of the soffit vents.
  • Won’t my shingles and the felt underlayment prevent leaks?  No.  Shingles and felt are designed to shed water from the roof, but are not sufficient to prevent leaks due to an ice dam.  What makes the difference and protects a roof from water damage caused by ice dams is the self-adhered roofing underlayment, which is installed underneath the shingles. Roofing underlayments perform many functions in a roofing assembly, but first and foremost, they serve as the last line of defense between homeowners and the damaging effects of water infiltration. Be sure you use quality self-adhered underlayment.  While use of a self-adhered underlayment is required by building code in places where ice dams are common, there are multiple product types that can be used. There is a wide variation in quality and performance. Premium performance self-adhered underlayments, such as Grace Ice & Water Shield®, seal around the fasteners used to attach shingles and other roof coverings, which helps prevent the water behind an ice dam from leaking into your house. These high-quality self-adhered underlayments stick to the roof deck, so that water may not travel under the underlayment and enter the house via a vulnerable roof deck joint. Lastly, best in class self-adhered underlayments seal at overlap areas. Water cannot flow or be blown under well-adhered laps. As a result, self-adhered underlayments provide real waterproofing protection that mechanically-attached alternatives like felt cannot match.
  • Where should the self-adhered underlayment be installed?  In cold regions you should certainly apply the membrane along the eaves, and in all valleys on the roof.  This is a basic requirement of the building code.  Additionally, you should protect other critical details and potential trouble spots.  Be sure to point out areas where leaks have occurred in the past, and where snow and ice loads were especially high in past winters.  Roof to wall intersections, chimneys, and skylights are frequently problem spots.
  • What if I don’t live in a place where it snows? Do I still need to use self-adhered underlayments?  The answer is yes.  While building code may not required self-adhered underlayments in warm climates, the same areas of the roof that are vulnerable to ice dams are also vulnerable to wind driven rain.  After the recent hurricanes, we received reports from homeowners who experienced significant shingle blow-offs, but who avoided major damage because their roof was covered with Grace Ice & Water Shield.
  • What do I do next?   Find a Pro – Identify reliable, knowledgeable professionals that can perform work safely. It’s usually best that all inspections, maintenance and repairs are completed by trained and experienced people. You should demand that they use high quality materials. The amount of money you can save by selecting less expensive lower quality products is insignificant compared to the damage caused by water infiltration.

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