Insulated Attic But Still Getting Ice Dams

Heavy snow coverage on the roof acting as a layer of insulation preventing heat loss.

Insulated attic but still getting ice dams.

Hot air from inside your house rises into your. An ice dam forms when the roof over the attic gets warm enough to melt the underside of the layer of snow on the roof. One way to help prevent heat build up and therefore ice dams is to have a well insulated well ventilated attic. It is recommended that if you have between 12 to 14 inches in your attic you should use cellulose and fibreglass.

Of fiberglass or cellulose fig. The conditions have to be just right but it can happen. Measure your attic insulation level while you re in the attic check the depth of your attic insulation. The water trickles down between the layer of snow and the shingles until it reaches the eave of the roof which stays cold because it extends beyond the side of the house.

And have had ice dam problems in the past. Ice dam prevention is best achieved in three ways. When the melted water at the eave refreezes it allows the water to backup thus causing ice dams. Cold air at the lower part of the roof.

So there you go that s why well insulated houses still get icicles and ice dams sometimes. Add more if you have less than 8 in. But if you have less than 8 inches and you have experienced issues with ice dams before add more cellulose or fibreglass. Building codes require about 12 to 14 in.

While some warm spots on the roof occur because of sunlight most are caused by heat escaping from the heated portions of the house. Warm air rising to the peak of the attic causing snow to melt and flow to the eave. If you have a problem with ice dams and see little or inconsistent insulation in your attic then attic insulation should top your priority list. Lots of snow on the roof insulating the attic.

Temperature close to freezing. Before adding attic insulation it s critical to find and seal gaps that let air from your home into your attic and vice versa. Any time you see icicles dangling from gutters it is a sign of a potentially costly problem in a home. If heat doesn t build up in your attic you probably won t have any ice dams.

If you can t afford to add more insulation to your roof for example by installing rigid foam insulation on top of your existing roof sheathing followed by new roofing you may have to live with the occasional ice dam. We typically use loose fiberglass insulation for attics in central oregon.