A question we get often from our clients is how frost ends up decorating their attic ceilings. Simply put, frost is caused by cold weather and air leakage. Miniscule leaks of air accumulate between boards or through tiny holes where moisture is able to enter. That moisture freezes, creating frost, but once it melts, water damage ensues. Melted frost from the attic creates those dingy water stains on the ceiling, can lead to deterioration in the roof sheathing, mold, and even wet insulation.
Air leaks can sometimes come from improperly installed exhaust fans. These fans need to be directed to the exterior of the home in every instance and never to the attic. Moist air will then flourish in the attic, causing frost to form and the above-mentioned problems to thrive. All bathrooms that are used for bathing should have exhaust fans installed—and only need to run for as long as sixty minutes to regulate humidity. The best way to ensure the fans aren’t running 24/7 is to replace your basic light switches with timers. There’s no need to have them on when a shower or bath is running, just afterwards to get the humidity out of the air.
The same goes for the kitchen exhaust fan, except you’ll want to run it while the oven is on and active. Ovens generate a lot of moisture. Another great way to eliminate moisture indoors is to consider installing a heat recovery ventilator, better known as an HRV. HRVs replace wet air from inside with dry, outside air and do a great job retaining heat as well.
To further rid your home of moisture, we recommend moving indoor plants, outside. Working from the bottom of the home, up also works well. Take steps to correct any damp areas in your basement and on the ground floors. The houses with the majority of the attic problems are usually split level homes or homes with more than one attic. Your HVAC system could be contributing to this problem if it is improperly installed or if the system itself has leaks. Make sure these are all sealed up to equalize the pressure in your home.
If every other moisture problem in the home is remedied or non-existent, and you still have frost problems, they must be addressed head on. As you’ve probably guessed by now, the most efficient and longest lasting way to prevent or remedy air leaks is to have them sealed. You’ll want to have every one of them sealed, not just the ones that are most obvious. Make sure that the leaks are sealed before you consider adding insulation or any other covering. This will only make the problem worse. Once you have proper ventilation and have gotten rid of all your leaks, voila! No more frost in the attic.