Heritage Restoration, Inc.

Domestic Ice Damming

Saw your article on ice dams. I want to resolve a disagreement with my wife….we have a cold roof/attic. Is ok to be preventative and install a manual roof and gutter de-icing kit to help prevent ice dams? Please let us know. Based on your projo.com article she says no and I say yes. Please help.

It depends on if you are a pessimist or an optimist. I would like to say this year will not be another bad year but anything can happen. A buildiIMG_3013ng with a history of ice dams will happen again without intervention it just depends on when. While proper retrofitting is best, a roof ice melt system can provide some piece of mind and perhaps some relief.

Did the roof have problems previously?

A cold roof system that is carefully built or retrofitted, using proper designed roofing systems, air sealing, insulation, and air flow will not have ice dams, even with the harshest weather. If the building has flaws, then you could get areas where ice damming can occur.

Testing performance

The building can be analyzed and tested. A blower door test, or negative air pressure test, can determine if the house functions well by how the air flows through the house. Also, having the cold roof system inspected for proper function can help. Air-flow has to be unrestricted, be it from the soffit, or overhang, to the ridge, or that the fiberglass insulation is spaced against the sheathing.

When all else fails

A roof ice melt system provides insurance when a building has flaws. The flaws can be poor drainage or clogged gutters and downspouts, bad flashing, failed roofing, missing or improper insulation, clogged vents, or any number of human error type building flaws. The effectiveness of a roof melt system is also about design and installation. You can forget to turn on a manual system, or the wires are in the wrong place, or they are too small, or the weather is just wicked.

If you feel you house is designed and performing well, then you do not need an ice melt system. But if you have seen the building perform poorly, or you just don’t trust it, then having an roof ice melt system is not a bad idea. I believe a roof ice melt system is a last resort. It masks a problem rather than fixing it. But as you say, it can be insurance too.

Let me know how it works out.