Opinions Vary on Causes and Cures for Ice Dams, Leaky Roofs

LITTLE ROCK, ARKANSAS – In the aftermath of one of the snowiest winters on record, many homeowners are now calling on roofing contractors to assess the damage from those darn ice dams and negotiating with the contractors about how to best remedy the situation. And they are finding out that there is a lot of controversy surrounding the subject.

For example, it is well understood that ice dams occur when snow repeatedly melts from one part of the rooftop and refreezes on another. Faulty design is usually the blame. Some building experts recommend attic ventilation; others swear by a soffit-to- ventilation, which allows cold air to circulate just under the roof and attics to be sealed.

If the roof could just be kept below freezing temperatures, so the theory says, then ice damming could be eliminated, or at least mitigated. Yet, truth be told, many homes are not properly designed to avoid ice damming. Homes in regions unaccustomed to heavy snow and freezing temperatures are especially susceptible. Old homes can be troublesome because builders lacked design the know-how to avoid ice damming when they were built. Some home simply lack enough ventilation in the attic or the air circulation may otherwise be obstructed. Also, sunlight and shade could yet lead to thawing and freezing directly on the outside roof, regardless of the interior temperatures.

It’s not surprising, all things considered, that ice dams and leaky roofs are not uncommon during a harsh winter. Homeowners can be seen with roof rakes, trying to break up the ice and get the water off the roof before it leaks into their living rooms. Once the water gets into the interior walls there can be future problems with mold and the thermal envelope of the home is compromised.

The truth is that shingles and roof felt are meant to shed water and typically do not provide a watertight barrier. Ice and water buildup on the rooftop is a disaster in the making. That’s why the International Residential Code recommends the use of a self-adhering modified bitumen sheet in areas where the average daily temperature in January is 25 °F (-4 °C) or less.

In recent years, sales of self-adhering membranes for extra protection against ice and water have skyrocketed. Most contractors now are familiar with their use and use them regardless of whether the home is old or new.

The extra cost for these premium membranes is cheap in comparison to the damage that could be incurred through a compromised roof. These membranes create an effective barrier against water intrusion typically caused by snow, ice and water buildup, melting and freezing, and expansion and contraction of shingles and other roof coverings.

This extra protection won’t prevent the formation of ice dam, which can still damage the primary roof, but it will help prevent leaks when ice dams do occur. And that’s a comfort worth having.

According to Steve Ratcliff, president of Tarco, Little Rock, Arkansas, there are many brands of self-adhering underlayment on the market today and they are readily available to roofing contractors. Installation does not require much more labor than installation of conventional felts but these tough, thick membranes provide far more protection.

“High winds, hail, heavy rain, snow loads, ice dams and other naturally occurring hazards can defeat even top-quality roof coverings and building designs,” says Ratcliff. “Smart installers today add an extra layer of protection under typical roof coverings to prevent unseen damage.”

Premium self-adhering underlayment is highly effective in critical roofing areas such as valleys, ridges, coping-joints, chimneys, vents, dormers, skylights and low-slope sections. The new products consist of a high tack, SBS-modified asphalt, which is reinforced with a glass fiber mat to ensure stability during installation. A split-back release film is provided to allow for easy handling and installation. This film peels off to expose the adhesive, which adheres directly to concrete, plywood, wood composition board and gypsum sheathing decks.

Products are available in one and two square rolls. (One square rolls are 36 inches wide by 33.4 ft length and two square rolls are 36 inches wide by 66.7 ft length.) They are available from home centers, lumberyards and building materials dealers nationwide.

For more information, Call Toll Free 1-800-365-4506 or email tarco@tarcoroofing.com. Address: TARCO, One Information Way, Suite 225, Little Rock, AR 72202. Phone: 501-945-4506, Fax: 501-945-7718.