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Damage from frozen pipes
Oct 28, 2005

Question: When I go away on vacation in winter, I turn the heat down for the time that I am away. When freezing temperatures plummet, what is the procedure to follow for protecting my home from being damaged by a frozen pipe? 

Answer: The first thing to do is to get your pipes inspected by a plumber to make sure that your pipes are in good condition. Ask a plumber about draining the plumbing system to prevent frozen pipes and water damage if you plan to be away a month or two. 

Also, ask a friend or a relative to check your home daily. Take protective measures by using 

either electrical heating tape on pipes that you know may freeze. Another product that is used is called Micro Air Duct, an insulated pipe made of compressed fibreglass with a foil covering that can be placed over exposed pipes and is sealed with duct tape.

But in the event you ever discover a frozen pipe, shut off the main water valve before attempting to thaw a pipe. This will prevent water from gushing out as soon as the pipe is thawed. 

Also, open the taps supplied by the pipes to 

reduce steam pressure, which can cause pipes 

to burst. Close the taps when the pipes have 

thawed. 

If the water isn’t running anywhere in the house, a pipe near the water meter may be frozen. To confirm this, touch the meter and the exposed pipes adjacent to it. If they feel extremely cold, a nearby pipe probably needs thawing. 

When water runs in only one part of the house, a pipe in an outside wall may be frozen. Turn up the heating system, or heat the pipes where they emerge from the wall. If a pipe is partly frozen, open the affected faucet all the way. 

Then, open other hot water faucets in the house to raise the temperature of the nearly frozen 

pipe. Once hot water is flowing from all the faucets, close them to a trickle. Don’t turn them off 

completely until water is flowing freely from the faucet. Once you’ve pinpointed the frozen section of a pipe, heat it slowly with a hand-held hair dryer or a heat lamp to a temperature your hand can tolerate. 

Work backwards from the faucet toward the frozen area. A cautionary note: boiling water, propane torches  or open flames of any kind should not be used for thawing. Pipes can explode if they are heated excessively or too suddenly. 

Check with a professional for additional information. 

Question: We had a cold snap this winter and just recently after a warm spell, we had water running through the light fixtures which damaged our stippled ceiling. We looked in the attic and there was quite a build-up of frost and ice that had melted due to the warm spell and the water was soaking into our insulation. What is the cause of this and will we need to replace our insulation? 

Answer: Unfortunately, many homeowners have suffered this same problem. An extreme cold spell will build-up frost and ice in an attic even when there is very little vapour pressure leakage into the attic from the home. Vapour pressure can leak into the attic through improperly weather-stripped and insulated attic hatch doors, improperly sealed ceiling fixtures and holes in the vapour barrier. 

If, added to this, the ventilation in the attic is not sufficient, then an extreme ice and frost build-up can occur.

When weather conditions are extreme and the humidity levels are high, problems are created. Some homeowners upgrade their insulation without upgrading their ventilation. I recommend one square foot of venting space to every 100 square feet of attic space. This is about triple what is usually recommended. 

The venting should be a combination of soffit or eave and roof ventilation. Even though you may have enough attic ventilation, an excessive leakage of moist air into the attic can cause this problem. 

Air sealing and proper ventilation of the ceiling is a must, as is having proper circulation within the attic by installing insulation stops and air chutes. 

Whether the moisture will permanently damage the insulation remains to be seen. Basically, it depends on the insulation you have. If damage from moisture leakage is extensive enough, it can prove to be quite costly. So, the dollars spent to upgrade insulation and ventilation in the attic now will save you a lot more in the long run.