*Special thanks to Bocc Home Inspections for this great article!

What is Attic Rain?

Attic rain occurs when moisture enters the attic space during colder months which then freezes and builds up a layer of frost within the attic. When temperatures rise, the frost melts and drips onto the upper level ceiling. Moisture spots and stains on the ceiling of the upper level (or main level in a single story home) can be a sign of attic rain.

When does is Occur?

Attic rain most commonly occurs when temperatures rise after a cold spell, during the winter months and in the spring. It is most common in newer home as they built to be more air-tight which reduces air flow and traps moisture within the home.

What Causes Attic Rain?

Attic rain is caused by moisture or warm moist air enters the attic space. Moisture can enter the attic in a number of ways, such as:

Gaps surrounding light fixtures
Bathroom fans with air leaks into the attic
Hood fans with air leaks at the attic space
Dryer Vents
Poorly constructed ventilation system
Poor seal around the attic hatch
High humidity in your home

How to prevent attic rain?

Keep your humidity settings below 30% in the winter, we recommend closer to 20%
Run your hood fan vent while cooking to clear out warm, moist air
Run your bathroom fan during showers and baths to remove humidity
Take a peek in your attic space to look for frost build up in colder months
Have an insulation specialist come in to ensure your insulation is adequate and has not been blown out of its proper place.

We recommend you take a look inside you attic during the winter to inspect for frost within your attic. If you see any frost, we recommend you hire an insulation specialist to come in and fix any air gaps, or if you are handy you may be able to caulk any gaps around vents in your attic yourself.

Attic Hatch