What is ICE and Water Shield?

Apr 27, 2016Blog, Ice and Water Shield

An ice and water shield is a key component of many Montgomery County roofing systems. Justwhat is ICE and water shield? It is a type of roof underlayment used in new construction and re-roofing projects. It is commonly used in leak-prone areas near eaves and in valleys. Also, it is frequently applied in problem areas like chimneys, skylights, dormers and vent pipes. Sometimes, for the ultimate in leak protection, this special membrane is installed across the entire roof.

A properly installed ice and water shield protects against the following:

  • Ice dams
  • Wind-driven rain
  • Flowing water
  • Seepage


Ice Dams – A Special Challenge

Recent severe winters made many Maryland property owners acutely aware of the problems posed by ice dams. Significant snow loads, combined with heat rising from living spaces, cause ice dams to form. Freezing and thawing cycles also add to the problem. Rising heat melts snow on the roof, but when the water reaches the edge of the roof, the heat source stops and the water freezes.

As this cycle repeats, ice dams can build up. Just as a lake forms behind a dam across a river, pools of water can gather behind ice dams. This standing water may migrate under roofing materials where it can cause dry rot, mold and/or mildew. The water may also migrate into the attic before staining and damaging ceilings and walls.

Installation of an effective ice and water shield is a proactive measure that can prevent expensive repairs and provide peace-of-mind.

Sometimes, severe winds in thunderstorms can create enough lift to allow heavy rain to work its way under shingles. From there, moisture can migrate down the roof until it reaches vulnerable areas. Also, heavy rain can increase flowing water to the point that it exploits vulnerable spots, especially those found in aging or improperly installed roofs.

The advantages of a high-quality ice and water shield are many:

  • Provides a good seal around nails and roof protrusions
  • Resists drying and cracking at very high and very low temperatures
  • Peel-and-stick membrane for easy, quick installation that cuts labor costs
  • Consistent performance under widely varying conditions
  • Provides a smooth underlayment that often results in a flatter roof
  • Addresses the special needs of low-pitch roofs


Installation Details

In partial ice and water shield installations, existing roofing materials are removed along eaves, rake edges, valleys and other problem areas, right down to the roof deck. The self-adhering ice and water shield is then applied directly to the roof deck, and the shingles are then replaced in these areas. To ensure that one gets the full waterproofing potential out of such a product, expert installation by qualifiedroofers is important.


Leak Protection Under Metal and Shingle Roofs

Ice and water shields are a valuable addition under a wide variety of metal and shingle roofs. GAF offers two kinds of ice and water shields

– StormGuard and WeatherWatch.



StormGuard is a film-surfaced membrane that is appropriate for use under both metal and shingle roofs. It is a Good Housekeeping Seal recipient, and it is a component of the GAF Lifetime Roofing System.



WeatherWatch is a mineral-surfaced barrier that is appropriate for use under shingle roofs. It features a fiberglass-reinforced layer that resists buckling and wrinkling under shingle roofs, promoting a flatter roof. It’s been awarded the Good Housekeeping Seal as well, and it is also a part of GAF‘s Lifetime Roofing System.


At BRAX Roofing, we’d welcome the opportunity to answer your questions about ice and water shields, and to explain further why they are a valuable part of many re-roofing projects.

Our experienced product specialists are available to visit your property to provide a no-cost, no-obligation estimate. Please contact us today to arrange for a prompt visit that fits your schedule.

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