Ice Buildup on the Roof
What are ice dams?
Ice dams form when the roof deck of your home is warmed by the sun or heat rising from your home’s interior, causing the snow covering your roof to melt. The melted snow runs down to the edge of the roof where it is again exposed to frigid air and refreezes, either on the roof edge or in a clogged gutter. When an ice dam forms, the additional snowmelt that runs down your roof has no place to go except to be forced back up and under your roof shingles and into the home. Once water gets into your home it can travel anywhere — along the rafters, across ceilings, down walls and even into the basement. The resulting damage can be extensive and expensive, with symptoms including rotted wood, mold, mildew, stains and cracked foundations.
What causes ice damming?
The cause of ice dams is not actually the roof, but the attic that lies beneath. If your attic gets too warm, it heats up the roof deck and causes the snow to melt. Natural weather patterns, building exposure, roof design and elevated attic temperatures due to both the insulating effects of snow accumulation on the roof and air leakage from the interior of the building can contribute to ice forming on roofs.
How can ice dams be avoided?
Are there solutions to my ice dam problems? The potential for developing an ice damming problem differs with every house, depending on a number of factors. Sun and warm weather can contribute to the problem, but just as significant is the amount of heat rising through the roof and melting the snow from the bottom up.
The secret to preventing an ice dam is to lower the temperature in your attic to match that of the roof, as well as some good backup options. Here are some suggestions that we recommend:
- Improving attic ventilation through increasing the amount of roof vents. Make equal the balance between in-take and exhaust vents. This allows air to circulate under the roof deck and not only prevents freezing, but also helps to avoid the build-up of moisture in the attic.
- Installing adequate insulation on the floor of your attic will keep the attic space cool (under proper ventilation). The insulation should not be directly attached to the underside of the roof deck. Good insulation will keep warm air from your home from rising up to the roof and heating the roof deck (thus causing the accumulated snow to melt). There is an added bonus, as insulation can also help reduce your heating costs.
- Professional removal of buildups of ice and snow can help reduce the likelihood of water leaks. This is a “medicated” approach, as it does not address the reason for the ice dam. Do not attempt to chip ice from the roof, as it can damage the shingles.
- Sometimes, it is advisable to install an ice and water shield for extra protection, especially on the eaves and valleys. This won’t stop ice damming, but can help prevent water from entering your home when it pools and gets under the shingles.
Other options and suggestions for avoiding “hot spots” or hot areas in your attic:
- Seal & insulate air ducts in attic spaces. Ducts must be sealed to prevent leaks in an attic and insulated well to prevent heat loss (and heat gain in the summer). Your furnace may heat the air up to 40 degrees Celsius or more and send it through leaky sheet metal ducts through a 0 degree (or less) attic. It’s inevitable that heat gets into the attic it’s running through. This means you get less heat delivered to the room intended – so you have to run the furnace more to keep your home heated – and that costs you money.
- Air sealing & attic insulation. Air sealing should always be done before adding insulation. In addition to preventing ice dams in the winter, attic air sealing can help solve other issues like drafty rooms, uneven temperatures, and high heating or cooling bills. Sealing leaks will help your attic insulation perform like it should. By insulating without air sealing first, air leaks (such as around can lights, drywall to stud seams, pipe and wire holes, openings around chimneys and duct chases, etc.) that need to be sealed will be buried under a foot or more of insulation.
Warranty and/or insurance.
What is covered by the warranty, and what is not covered?
Ice and icicles are a natural occurrence on roofs and is not covered under the statutory warranty unless there is a demonstrated BC Building Code violation or a defect in work or material supplied by the builder.
Some examples of what would be covered by a workmanship warranty.
- Insufficient amount of nails used to secure the shingles.
- Poor alignment of shingles.
- Overexposure of shingles.
- Vents and flashings that are improperly installed.
Some examples of what would be covered by the Shingle Manufacturer’s Warranty:
- Defective Shingles.
- De-lamination of asphalt shingle roof.
- Recalled Shingles.
What problems would NOT be covered under my workmanship or shingle warranty?
Any environmental damage or any damages that are not directly related to poor workmanship or shingle products, instead these are covered by your home insurance.
- Wind damage.
- Hail damage.
- Ice dams.
- Structural problems.
- Minor issues with exterior.
- Wildlife Damage.
Will my insurance pay for ice dam removal?
Why doesn’t your insurance company typically pay for ice dam removal? Insurance professionals have explained it to me with the following example:
Ice dams are like a mighty oak tree hanging over the roof of your house. If the tree falls on your roof, your insurance will almost certainly pay for the repairs to your home. The insurance company may even pay to remove the part of the tree that fell on your house (though they typically won’t pay to remove the remainder of the tree in the yard, grind the stump, etc). However, they’re not going to come out and remove the tree only as a preventative measure. Why? Because there’s a good chance the tree will not fall, and even if it does it may not fall on the house. It would be a slippery slope for the insurance company; they can’t pay for the removal of all the trees that homeowners feel is a little too close to their home.
Insurance companies are not in the “tree trimming” business just like they’re not in the “ice dam removal” business. A certain responsibility falls on the homeowner to do their part in protecting their own home. You have a responsibly as a homeowner to show due diligence in protecting and maintaining your home. This is stated in most all insurance policies.
It’s the same with ice dams. Your insurance agency will almost certainly cover the damage done to your home caused by your leaking roof, and they may even pay to remove the portion of the ice dam that’s directly causing the leaking. But typically the removal of the ice dam itself is considered to be the homeowner’s responsibility.