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Southern Alberta home owners facing attic rain


Attic rain is a phenomenon caused by extreme cold weather followed by a rapid warm up.

Condensation forms inside an attic of a home in the cold. But when it get warmer, that condensation melts and rains down onto the insulation. With good air flow in an attic, this shouldn't be a problem for many home owners because the moisture that dripped into the insulation will evaporate naturally.

It becomes more of a problem when extra moisture is released into the attic.

Bob Sellan lives in southeast Calgary. One night, his wife stepped onto wet carpet in a second floor bedroom. They then noticed a water stain on the ceiling and water pooling in a light fixture.

"My first thought was that we had some more (shingles) blown off and water was coming in with it melting the snow on the roof," said Sellan. "But that wasn't the case at all."

Cody Sager is a sloped division repair technician with Calgary Elite Roofing. He's working more than 12 hour days responding to calls like Sellan's.

"With these nicer weather days, (like) the last two days everything melts," said Sager. "So by the time I get up there the insulation's wet, the trusses are like wet logs,(and)  it just makes it hard to do my job -  but pretty easy to explain to the customer that they had an issue."

Sager discovered that a bathroom exhaust fan vent had come loose from the roof vent. Moist air was being pumped into the attic for days creating what he calls an ice caste.

Sager will use new ducting to make sure the vent doesn't come apart again.


Greg Garcia is the president of Elite Roofing and says it's important for home owners to anticipate the weather. When a cold snap is forecast he recommends turning down your humidifier. Reducing the moisture inside a home will also reduce condensation in the attic.

"It's not a huge problem don't panic," said Garcia. "You'll see a little bit of water and maybe some stain here and there, call your roofing company just to make sure everything is fine."

Garcia says keep an eye on windows when it's cold. If there is ice forming at the bottom that means there's likely too much moisture inside and it's a good idea to turn on bathroom fans to vent that air.

Garcia says his team of 16 technicians will be busy for at least another month dealing with all the attic rain complaints.

"If the weather is milder and the raise of the temperature is slower, those problem will not happen," he said. Top Stories

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