Winter in New England is harsh and beautiful. It is
inspiring to be surrounded by pristine snow covered fields and hills. Many of
us enjoy the snow topped roofs and the spectacular crystalline icicles that
adorn our homes. As a home inspector I have the privilege to witness these
sights in our many historic homes here in Fairfield County. These sights can
also distract from the all to familiar hazards that these conditions can
create. The spectacular icicles can be an indication of a condition that can lead to costly repairs.
Ice Dams can be a problem during the cold months of the year. Ice dams can damage gutter, roof shingles, soffits, landscaping, interior walls and ceilings. The large icicle formed as a result of ice dams pose a hazardous condition to those that are below.
What are causes for Ice Dams?
Ice Dams are caused when the temperature of the roof varies in sections. When the upper part of a roof warms, snow melts and the water flows down the roof. As the water gets to the edge of the roof is refreezes. The ice will build up in the gutters and restrict drainage of any remaining water. As this process continues and repeats the ice will build up and form an ice dam. If this continues to happen the ice can work under the roofing shingles. This can all be due to poor ventilated attics or lack of enough insulation. Heat from the home warms the roof. The soffit is the section of the roof that over hangs the side of the home. The soffit will be cold and this is where the water will refreeze causing the ice dam. As the dam continues to grow it will eventually reach a section of roof that is over the heated section of the house. The ice will melt and may drain under the shingles into the attic, ceiling and walls below.
Typically the cause is heat from the interior getting into the attic. Poorly sealed and insulated attics can allow warm air from the home to enter the attic and in turn heat the roof. In New England it is recommend that an insulation level rating of at least R-38 be used in the attic. Some of the trouble spots can be recessed lights and attic pull down stairs. Building a simple box from foil backed rigid foam insulation and placing it over the pull down stairs can reduce a lot of heat loss to the attic. Bathroom exhaust fans should be routed to the exterior and not into that attic or soffits. By reducing warm conditioned air in the attic it will limit heat transfer to the roof. The attic should be cold.
What to do about Ice Dams?
This is where the best solution is prevention. If your home has a history of ice dams it is important to take steps to prevent them in the future. The first step is to address the heat leaks from the interior. Where ever possible, seal and insulate to prevent air movement from the living space into the attic. Installing additional insulation to reduce heat loss to the attic can go a long way to preventing ice dams. Do not put insulation over recessed lights unless they are rated to for “Insulation Contact” (IC), otherwise there can be a risk of fire. The next step is to have proper ventilation. The ideal situation is for the roof to be the same temperature from the edge to the peak. Soffit vents with a ridge vent will allow air to flow along the under side of the roof from the soffit to the ridge. It is important to keep insulation pulled back away from soffit vents to allow for proper airflow.
Another possible solution is to install heat cables along the lower section of the roof edge and in the gutters/downspouts. This type of system will help to keep that ice from forming and allow for the water to drain.
I have Ice Dams what do I do?
Unfortunately there is no easy solution for fixing the problem of ice dams once they have formed. They must be dealt with or you run the risk of water, roof and gutter damage.
1. Ice Dam removal company- Yes they do exist. The typical removal process is to steam the dam away. It is very effective and the best solution. Also you can try reputable roofing contractors. This is the solution that I recommend.
2. Remove snow from the roof- Remove the snow from the roof with a specially designed roof rake. These rakes will have a long aluminum handle and wheels to allow it to roll over the roof surface. Always pull the snow to the edge of the roof, never rake or shovel upwards as this will damage the roofing shingles. Be careful not to pull the snow down on top of yourself.
3. Chipping away the ice dam- this can be very dangerous and although it may be a solution it is also one that comes with the most risk. The idea is to chip away the ice and allow the water to flow. The risk is that it requires the use of a ladder and sharp objects. Using a blunt mallet is a better choice. Great care must be exercised to prevent personal injury and damage to the roof itself. Focus on the gutters and downspouts; if the gutters can drain then the melting ice will drain as well. Be warned this is a last resort and should be performed at your own risk.
4. Melting salts- this is another possible solution, but salts can be corrosive and the run off will most likely damage landscaping below. Use calcium chloride instead of rock salt. Rock salt can damage paint finish, damage metal surface and deteriorate concrete walkways. Try to use the salts to create troughs to allow water to drain. One suggestion that I have come across was to put the salts in an old pair of pantyhose. Some have had success using salt tablets in gutters to keep them from freezing and allowing for drainage.
Snow, Ice and extreme cold temperatures can lead to damaging conditions. When it comes to Ice Dams prevention is the best solution.
Jason Horn is an ASHI Certified home inspector in Newtown, CT and one of the lead inspectors at Stonehollow Inc., a home inspection firm with offices in Newtown and Stamford that services all of Fairfield county and most Western CT. If you have any home inspection related questions feel free to call him at (203)304-9140