What Can I Do About Ice Dams?

Pretty icicles? Yes. Problematic ice dam? Also yes. (photo by Suat Eman)

What is the most beautiful feature of a winter landscape?  Many people would answer that the long, elegant icicles hanging off of a house are.  And what is the most common cause of interior paint failure during the winter?  Same answer.

“Ice dams” are rims of ice along the outside of your roof that are formed by the differential heating created by your house’s microclimates.  In short, warm air from your climate-controlled home rises out through your roof, warming and melting the wintry precipitation that has collected there.  That melted snow and ice runs down your eaves and collects around your gutters and the rims of your roof.  Since the heat is concentrated in the center of your roof, the water that runs down your eaves tends to freeze again once it gets to the gutters, creating a rim of ice known as an “ice dam”.  As more and more fluid gets added to the ice dam, it runs over the sides and creates the beautiful hanging draperies and icicles that enchant the imagination.  It also adds weight to the edges of the roof, tearing down gutters and shingles, and in some cases causes the water to back up into the house, causing a signature pattern of water damage, mildew growth, and general paint failure.  Paint failure caused by ice dams is so common and so distinct that the trained eye can diagnose it within seconds.

If you suspect that you have paint failure caused by ice dams, or if you notice ice dams on the rims of your roof and are concerned that water damage might soon follow, Blue Door Painters estimators are thoroughly trained in spotting and mitigating this unique problem.  In addition to repairing any existing water damage and repainting the problem area, there are certain steps you can take to prevent damage from ice dams in the future:

1. Check the insulation in your roof.  Improperly insulated roofing is a leading cause of ice dams, because the snow will only melt if a sufficient amount of your household’s heat escapes to melt it.  Ensuring that your roof is properly insulated is a wise idea anyway, because it will impact your heating bill.

2. Consider adding a roofing ventilation system.  Soffit-to-ridge ventilation systems are some of the most effective additions to a roof that keep it cold enough to avoid snowmelt, although retrofitting existing roofs with this kind of surface can be challenging.

3. Reinforce the waterproofing around the rims of your roof.  This can be done from the interior or the exterior, and will prevent the water from entering your house even if an ice dam does form (although it won’t save your gutter and shingles from the mechanical damage caused by the weight of the ice dam).  Just be aware that the water will collect and rise above the waterproofing section if it is not escaping into your house, so you should waterproof a larger area than you expect to see damaged.