Stock photo licensed from

Icicles on the Eavestrough

Posted February 14th, 2011 under renovations and repairs.

Often we see the long icicles that hang from the eavestrough at the side of a house. They're formed when snow melts on the roof, runs down to the roof to the eavestrough, then freezes again as it trickles over the edge.

If you notice these icicles on your house, see if you can determine when they're forming. If the weather is warm or the sun is shining, the snow is melting because of the weather and then re-freezing because the side of the house is cooler or in shade. This is a normal process and nothing to be concerned about.

However, if the icicles are forming when the temperature is below freezing and the sky is overcast, you may have a problem. For snow to melt in this situation implies that heat is escaping through your shingles and melting the snow from beneath. This can cause moisture to enter your roof and damage it.

Heat escaping through the shingles can happen for two reasons: insufficient insulation in the attic, or excess warm air escaping into the attic from other parts of the house.

Before assuming it's your insulation, you should check for the following:

Older homes are particularly prone to improperly-installed venting. When warm, moist air vents into the attic it can also cause mold. To inspect for this possibility, look at the underside of your roof sheathing (in the attic), which may show dark patches due to the mold and dampness. In the winter you may even see ice patches forming on the underside.

Either of these signs is a confirmation that warm, moist air is being vented into the attic. If you notice any of these problems, you would do well to correct them as soon as possible.

By avoiding mold and water damage you'll save yourself considerable repair costs down the road.

Want to know more about detecting roof damage? Just ask me, I'll be happy to help.


Get monthly real estate advice in your inbox, free! privacy policy