Key Highlights
- Ice dams form as a result of snow that melts because of heat from the attic and refreezes at the eaves.
- Ice is heavy and can cause roof leaks, damage your gutter, and even cause mold.
- Ice dams are caused by poor attic insulation and inadequate roof ventilation which allow heat to flow from your attic to the roof and melt snow.
- To prevent ice dams, you’ll need to work on the attic insulation (make sure there are no leaks) or improve the roof ventilation.
- To further reduce the chances of ice dams, use a snow rake to remove snow from the roof, especially after a snowfall.
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Ice dams are a typical winter issue. They happen when there is a big difference between the temperature of your roof and the outside temperature. If your attic insulation isn’t good enough, heat can escape through the roof. This makes snow melt on the warmer areas. The water then runs down to the colder eaves and freezes again, creating an ice dam. It’s really important for homeowners to understand ice dams and what causes them. This knowledge can help you protect your home from expensive damage.
What Are Ice Dams and How Do They Impact Your Home?
How Do Ice Dams Form?
Heat transfer is the reason ice dams form. If the attic is not well insulated, your home’s heat will rise and escape through the roof in winter. So that bit of the roof is warmer than the surroundings, even if it’s freezing outside.
When snow falls on the roof, the warm areas begin to melt the snow away. The melting snow moves down to the eaves—which aren’t warm from the heat in the attic.
When the melted snow from the roof hits the cold eaves, then it’ll refreeze and make an ice dam. Every time it snows, this process continues. This can cause big ice dams that are really, really hard to clear off with a snow rake.
Why Should You Worry About Ice Dams?
What most people don’t realize about ice dam damage is that it’s more than just ugly icicles hanging off your roof. Heavy ice can pull gutters down, lift shingles, and in some cases, damage your roof’s structure. If the water backs up behind the ice dam, it can leak into your home. It can result in water stains on your ceilings and walls or peeling paint, along with crooked attic floors. From ice dam damage, your house traps moisture that’s perfect for mold to grow. It can weaken your home and be very bad for your health and that of your family.
Primary Causes of Ice Dams
Inadequate Attic Insulation
One thing you should know about heat is that it is energy (a form of it at least). That feeling of warmth or coolness when you touch an object is simply due to heat energy either moving from your hand into the object (the object will feel cool) or from the object into your hand (the object will feel warm).
If your attic is properly insulated, this heat transfer does not happen (well, realistically, it’s minimized instead. Given enough time, your attic will be as cold or warm as the outside. No two ways about it). Therefore, the snow on your roof won’t melt and begin the first step of ice dam formation.
Without proper insulation, the attic will lose heat energy to the snow on the roof which will melt, breeding the ice dams you don’t want.
Poor Roof Ventilation
Proper roof ventilation is as crucial as insulation when it comes to preventing ice dams. Effective ventilation allows for continuous air circulation within the attic space, exhausting warm, moisture-laden air and drawing in cold air from the exterior. This helps maintain a consistent roof temperature, reducing the likelihood of snow melting and refreezing at the eaves.
Roof vents, typically located at the eaves and ridge, facilitate this air exchange. Soffit vents, installed under the eaves, draw in cold air, while ridge vents, running along the peak of the roof, expel the warm air. For additional airflow, you can have gable vents on the gable ends of the roof.
How Can You Effectively Prevent Ice Dams?
If you’ve been paying attention, you’ll see that preventing ice dams is fairly straightforward:
- Make sure your attic insulation is as good as you can make it
- Try to keep the attic at a temperature closer to the outside with good airflow
These help keep a steady roof temperature, which is important to reduce ice dam formation.
Also, it’s crucial to seal any air leaks in your attic. Check for gaps around electrical wires, plumbing pipes, chimneys, and attic doors. Closing these leaks helps stop warm air from escaping into the attic. This will keep roof temperatures even and lower the risk of ice dams.
Improve Your Attic Insulation
As we saw in the last section, ice dams occur when there is heat transfer between your attic and the snow on your roof. To ensure there’s effectively no heat transfer, you need to ensure the heat in your attic can’t reach the outside. One way to do that is with proper insulation.
Heat transfers when the intervening material between the two objects or bodies of interest (attic space and roof) is willing to let it happen. Metal is the most willing. Foam/plastic is one of the least conducive. Since replacing the roof with foam isn’t an option, insulation is the next best thing. That way, your roof will easily maintain the temperature of the snow and keep it from melting.
When checking attic insulation, look at the type and thickness. The R-value you need for your attic can depend on where you live but usually lies between R-38 and R-60.
- Check existing insulation: Make sure your insulation meets the R-value needed for your area.
- Address air leakage: Close any gaps or cracks in the attic floor. Look for leaks around wiring and plumbing vents to keep warm air from getting into the attic.
By ensuring your attic has enough insulation and fixing air leaks, you can lower heat loss and reduce ice dam formation on your roof.
Improve Your Roof Ventilation
Despite the ‘roof’ in the name, roof ventilation is actually about making sure the attic is close to the temperature of the outside. At this point, insulation is useless. With vents, you instead make sure cold air from outside flows in (with soffit vents) and warm air from the attic flows out (ridge vents. Gable vents are optional).
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Ice dams can cause serious problems for your home if you don’t deal with them. To stop ice dams from forming, it’s important to know how they happen and the damage they can cause. Make sure your attic is well-insulated and that your roof has good ventilation. This will help protect your home from harm.
Don’t wait for winter to start preparing; act early to avoid expensive repairs. If you have questions about ice dams or need help cleaning your gutters, contact us at Arizona Window Washers. Take steps today to protect your home and keep it safe.
