What Is Attic Rain & How To Prevent It?

You have heard of spring showers, but have you heard of attic rain?

It is a term applied to the warm moist air that collects in the interior attic space and freezes on the internal roof structures, forming ice and frost. When a warm spell hits, the frozen water seeks a way out of the attic. It will run down walls, soak through the OSB plywood in the roof and collect around lighting fixtures and piping.

The water often leaves a brown stain from the chemicals picked up in the attic’s building materials. You sometimes think it is a leaky roof, but attic rain builds up due to increased moisture from interior sources. The average household puts 50 litres of moisture into the home weekly.

What Causes Attic Rain?

The exact cause can be hard to determine. Still, there are a few things that contribute to frost accumulation and attic rain in the attic.

• Inadequate roof air intake & air pressures, poor ventilation and soffit venting
• Inadequate or poorly installed insulation
• Moist air from the home’s interior escaping into the attic. Cooking, bathing, laundry, & humidifiers add moisture to the home’s interior
• New home energy efficiency standards leave homes airtight leaving moisture no escape route

What Are Some Signs Of Moisture Damage?

Look for any moisture and stains on walls, ceilings, around light fixtures, and vent stacks. If your windows are wet with condensation, it may be a sign of too much humidity in the home.

Any black areas may mean toxic mold, and there are special precautions to remove this. A qualified specialist should dispose of the materials affected.

Take pictures of any suspected water damaged areas. It will help the roofing specialist investigate your concerns. It is also good to have a record for insurance purposes.

Inspect the attic for signs of ice buildup, moisture stains or wet insulation. Again take pictures of frost, ice buildup, vents, and moisture signs. Call in a professional YYC roofing company to inspect your attic and roof for areas of moisture damage.

If your home is a new build, you may be qualified to apply for assistance through the Alberta New Home Warranty Program.

What Can I Do To Reduce Moisture In My Home?

There are a few things homeowners can do right away to reduce moisture in the attic.

The furnace usually has a fan that helps balance air intakes in your home. Many people think they are noisy and turn it off, or they forget to turn it on again in the fall. Turn the fan back on.

If you are unsure about the air pressure regulation and ventilation processes in your home, talk to a furnace and roofing specialist. They may talk about a Home Recovery Ventilator (HRV) and Principle Ventilation Fan (PVF). Set the HRV controls to continuous, and the PVF switch is usually on or near the furnace. Turn it on.

Make sure all your appliances’ vents are connected. Dryers are a big culprit. Temporary venting can come off the back of the dryer and all that moist air filters into the house. Use your bathroom fans after showers or baths. Many people forget that they are there for other reasons than getting rid of bathroom smells.

The stove fan should vent to the exterior of the home. Check if it is and use the fan when cooking. It is excellent for venting smoke from the occasional culinary accident. Still, its primary purpose is to remove moisture from the home’s interior.

Turn Off The Humidifier

Check your walls and floors for temperature differences. Make a note of them for the professional roof inspection. If they are cold, there may be an air leak into the attic or an uninsulated void: note insulation levels, grade, and quality for possible improvement.

If you have leakage around electrical fixtures, cut the breaker to the switch if you can. Otherwise, tape the switch or plug off for safety purposes until a contractor can come and fix the leakage. Caulk or seal around fixtures and pipes leading into the attic. The small spaces around these areas can let moisture into the attic.

If there is a large area of ceiling where water saturates the drywall, call a roofing company immediately. Keep family members and pets away from the area, in case the ceiling drywall falls.

Additional Measures to Protect Your Roof and Attic:

1. Ice Dam Prevention: Be aware of icicles forming along the edges of your roof, as they may indicate ice dams. These can force water along the drip edge of the roof, leading to roof rot.
2. Snow Removal: Use a long-handled rake from the ground to clear snow from your roof. Avoid using a shovel or getting on the roof yourself, as it can be dangerous.
3. Proper Attic Insulation: Check the roof ridge in the attic for sufficient insulation. Replace any wet insulation, as it loses its insulation value.
4. Sealing Attic Bypasses: Look for and seal common locations of attic bypasses, including:
   • Chimney
   • Tops of walls
   • Plumbing & electrical entry
   • Light fixtures
   • Dropped ceilings
   • Knee walls
   • Fans
   • Heating ducts
5. Outdoor Precautions: Knockdown overhanging snowdrifts and shovel snow away from the walls of the house to help prevent ice dams and reduce home moisture levels.

Know When To Call A Professional

Call a qualified roofing company to evaluate your home. There are many things to be considered, as your roofing system works together with other systems in the house to ensure a safe environment for your family.

Ice dams can also be a cause of major roofing headaches, like attic rain. Check out our article on ice dams and why you don’t want to let them buildup. If you need help checking your attic for potential damage, give us a call or fill out our convenient automated online contact form.