How does SuperPerf Radiant Barrier Help With Ice Dams on My Roof?

As I talk about on the AtticFoil® site, adding a radiant barrier inside your attic can usually REDUCE the possibility of ice damming.

Ice damming is caused when the top of the roof warms above the freezing point the the lower part of the roof is below freezing. When this happens, the icy roof water melts and that water trickles down and refreezes at the edge of the roof where it’s cold. The roof gets warm due to warm air leakage into the attic from the home or from duct work inside the attic space.The roof can also warm up if the sun comes out that day. A roof with snow can get hit by the sunlight, which warms up the roof and begins the melting process. By the time the sun sets, and the temps drop again, that watery edge can re-freeze, creating ice dams and icicles.

The Key to preventing ice dams

To prevent ice damming, you want a COLD roof. The roof gets warm due to warm air leakage into the attic AND from the home emitting radiant heat. A radiant barrier will help keep the radiant heat emitting from the home from hitting the roof. The result is a COLDER roof deck which will reduce ice damming. Many customers have seen a significant reduction in ice damming after installing AtticFoil radiant barrier. I would also suggest checking to make sure you have good attic ventilation. Cold air entering the attic will also help keep the roof COLD.

Fix Ice dams now!

Now you know what ice dams are and how to prevent them, but what if you’re dealing with them right now? Not to worry, I have some tips that can help you fix the problem and keep ice dams at bay.


Ventilation helps your attic stay cool by funneling cold air from outside through the attic space and out somewhere near the upper third of the roofline. Ventilation keeps the air temp in the attic cold, and it helps dry up condensation or moisture.

Air Sealing

Air can easily leak out of ceiling penetrations (think ceiling fans, can/recessed lighting, vents, etc.) and into the attic space. Make a plan to go up into the attic, revel these areas and then work to seal them up. A small can of spray foam can go a long way toward sealing up cracks and spaces in these areas.

Radiant Barrier

Many customers have seen a significant reduction in ice damming after installing AtticFoil™ radiant barrier. Whether you’re stapling the foil up on the rafters or using the SuperPerf™ that was designed to go on top of the attic insulation on the attic floor in cold climates, you’re helping keep heat in the house and off the roofline.

For an attic with ductwork or HVAC/furnace equipment in the attic, a staple-up method is your best bet. Staple the foil up everywhere under the rafters. If you live in a mixed climate and would also like the benefit of helping keep the heat in during the cold months, go ahead and do a second layer of foil by adding SuperPerf™ on the floor over your insulation everywhere else. If your attic is empty of ducts or HVAC stuff, then you can just do the one layer of SuperPerf™ on the floor. Click here to see how to install AtticFoil ™ SuperPerf™ for cold or mixed climates.

Final Thoughts

Ice dams happen because your roof temps fluctuate between warm and cold. If you can keep your roof deck constant and equal to ambient (outside) air temperatures, you can greatly reduce the chance of ice dams forming on your roofline. The easiest way to do this is by adding a radiant barrier in the attic space. If you want to do more, consider checking for proper attic ventilation and well-sealed ductwork. All of these combined will help you eliminate the problem of ice dams forming on your home.

Leave a Reply

Your email address will not be published. Required fields are marked *