What is an Ice/Water Shield?

More roofing definitions

Anyone living in an area of the country with winter weather is probably familiar the ice/water shield - and may have come to their knowledge the hard way. An ice/water barrier is a thin layer of waterproof material that prevents damage of the roof from water buildup behind ice dams. It can be used under most roofing types including asphalt shingles, slate, and copper. Although this shield is an added expense when putting a new roof on a home, it is far less than the cost of fixing water or ice damage that could destroy a roof, especially in northern climates.

Purchasing and Placing an Ice/Water Barrier

Ice/water barrier is usually sold in rolls; the standard size being 3 ft. wide. There may be slight variations in thickness and weight of the material. There are also several surface treatments of the material: sand, granular, and film. Film is the smoothest and can become slippery when wet. A granular surface is similar to that of a shingle and is the heaviest and most rigid of the three. Sand surfaces have a fine layer of sand glued to shield.

Ice/water barrier products vary in price depending on the brand and company, but in most cases, a 50-foot roll can be purchased for about $60. Most ice/water shields are self-adhesive and are not meant to be punctured or held in place by nails or staples. In fact, once applied, this material will seal nails, staples, and any other holes that could allow water to leak into the wood or an attic. The ice/water barrier should be applied over both eaves and valleys of the roof, but the creases in the barrier should not match the creases in the roof. Instead, the ice/water barrier is meant to cover these creases and safeguard these vulnerable areas from leaks or damage.

Ice/Water Barrier Codes

The roofing codes that mandate how much water/ice barrier should be used on roofing projects will be different from region to region. The roofing codes in Minnesota, for example, require that two layers of an ice/water shield be adhered to the roof before the felt or finished roofing product can be added. Other areas will have different codes regarding water/ice barriers, depending on the climate.