Dealing With Ice Dams On Your Roof
There are many schools of thought on the causes and solutions to the ice dam problem. Here are a few of my personal observations and experience as a contractor in Connecticut for the past 25 years.
Let’s start with what causes ice dams. If you have temperatures below 32 degrees Fahrenheit, snow on your roof and a source of heat to melt the snow you most likely experience ice dams on your home. The heat source can be strong sunshine on a southern exposure but more likely heat escaping from your living space. As melting snow trickles down and hits the cold overhang of your roof, it saturates the snow that is sitting on the overhang and in the gutters. This will eventually turn to ice.
With each passing day filled with freezing temperatures and snowstorms that ice dam grows thicker and wider until water from melting snow can no longer run off the roof. Once there is enough water accumulation that cannot escape, the water can get under roof shingles and start leaking into your home. Once water leaks occur your home can become damaged. The types of harm can range from a small spot on a ceiling to major damage to ceilings, walls, floors, and home contents. In some cases even major structural damage can occur. If extensive water leaks occur in your home Sheetrock and insulation will likely need to be replaced. Insulation that has been saturated with water will not return to its original R value. Ceilings, wall cavities and floors will be slow to dry. If mold and mildew are formed it can compromise the wellbeing of allergy sensitive individuals.
So how do you prevent ice dams on your home?
- Keep your attic well-insulated (at least 12″ R-38). This will help keep heat in the living area of your home and out of your attic
- Make sure air leaks are sealed. Areas that usually need attention are attic access points, plumbing and wire penetrations into the attic and recessed light fixtures.
- Check to see that bathroom and kitchen exhaust fans are vented to the exterior of your home not just into your attic space.
- Make sure your attic is well ventilated. This will help keep the temperature in your attic consistent with outside temperatures.
- Water and ice shield a self-sealing, self-adhesive shingle underlayment. This is now required on the first 36” at the eaves and in roof valleys according to Connecticut building codes. If your home has overhangs wider than 12″ or a shallow pitch under 5/12″ and is due for a new roof consider using two rows of water and ice shield on the eaves and in valleys for extra protection. It’s fairly cheap insurance and great peace of mind.
- If all else fails home heat cables may be your only alternative. Follow manufacturer instructions or have a professional install them. The cables will help ensure water has a path off your roof and not into your home.
From my experience there are no sure cures that work in all scenarios. What resolves an ice dam issue on one home may not work on another. Adding insulation is a great place to start and has the added benefit of increased energy savings. Cures are often elusive and sometimes very expensive. In some cases you need to treat the symptoms, the payback being damage prevention. Remember THINK SPRING!