Stay Dry

Don't let Attic Rain be a wet blanket.
  • Comfort
  • Attic Rain
  • Comfort
  • Attic Rain
Stay Dry

Don't let Attic Rain be a wet blanket.
Attic Rain

If you've ever seen tennis-ball shaped water stains on your ceiling, you might be experiencing a phenomenon called ‘attic rain’.

Attic rain occurs when warm moisture accumulates in the attic, freezes during cold temperatures, then melts when the weather warms again. This see-saw in weather produces the perfect attic-crying conditions to damage your house. The kicker? It usually affects newer homes because there are less places for air to escape. Our Flow service professionals can investigate the issue, identify any further concerns, and make sure the moisture stays where it belongs.

The Cause of Attic Rain
Attic rain occurs when heat and moisture from everyday activities such as cooking and doing laundry leak into the attic. When temperatures are cold, the moisture turns into frost and can settle into layers up to eight inches thick. The longer the cold period lasts, the more frost can accumulate until warmer weather comes around or one of Alberta’s famous Chinook winds blows through.
Avoid Attic Rain
  • Check to see if your attic is well ventilated:

    Caulk around any fixtures or vents that have not been adequately sealed.

  • Make sure your vents go directly outside:

    You want to avoid having them go through your attic. See this resource for sealing your attic Resource

  • Turn down your humidifier:

    The ideal moisture level for your house is 30%-50%.

  • Turn on your kitchen exhaust fan when cooking.
  • Install an HRV:

    HRV stands for (Heat Recovery Ventilator). HRVs replace damp indoor air with dry outdoor air.

  • Contact your builder:

    Ultimately, your attic should already have a mechanism to deal with the airflow and moisture build-up. If it wasn't included in your property, it may be a symptom of poor design. Check the attic before you invest in a home.

If you’re still having problems with attic rain and are unable to figure out the issue, our team of experts is ready to flow.
How Can I Prevent Attic Rain?

Preventing attic rain is all about controlling the moisture inside of your home. Here are some tips for keeping moisture levels down.

  • Do not run a humidifier if your indoor humidity is between 30%-50%.
  • Turn on your oven hood exhaust fan while cooking.
  • Turn on your bathroom exhaust fan while showering or doing laundry.
Why Is Attic Rain Becoming More Common?

Attic Rain is becoming more common because of newer and more energy-efficient homes. New construction homes in Calgary, Edmonton, and throughout Alberta are far more airtight and do a much better job at trapping moisture and warm air inside. This is why many new homes have a whole-house ventilation system that exchanges all of the air inside of the home with outside air.

If your home does not have this system or if you don’t run it often enough, then you could end up with attic rain. Contact Us today if you believe your home suffers from issues related to Attic Rain.

Flow is your one-stop shop for expert service. We specialize in providing Calgary residents with the most comfortable spaces possible. Whether plumbing, heating and cooling or HVAC services, our professional technicians are certified and ready to help.


6323 35 St SE
Calgary, AB T2C 1N1


This email address is being protected from spambots. You need JavaScript enabled to view it.

Normal Office Hours

Monday - Friday 7:30AM - 5:00PM

Site Map 2022 Flow. All Rights Reserved. | Privacy Policy