The Inside Outside Guys: Seal Your Ceiling
By Ken Calverley and Chuck Breidenstein
DETROIT, February 3, 2022 ~ You’ve seen weather patterns before where warm, moist air, rises, cools and turns to ice only to eventually melt and rain back down.
But I’ll bet you never witnessed it in your attic.
We’ve previously discussed how warm air will gather moisture and rise – literally the stuff that makes up our weather patterns. But what a lot of us don’t realize is that the same dynamic can take place in our homes.
We introduce heated air at the bottom of the exterior walls during the winter months, knowing it will rise and move to cooler surfaces. As it rises, it may gather moisture from us, houseplants, aquariums, pets, laundry and the kitchen.
What we would like to have happen at this point is for that air to enter the return air portion of our duct system and get re-cycled through the home. If this humidity stays in the home, we are generally healthier and more comfortable.
But there are impediments lurking in most homes that often re-direct that warm, moist air.
Electrical receptacles located at the lower portion of walls have wires running from them in the wall cavity up and through holes in the top plates of the walls. These create what we call “raceways,” where warm air will follow the wire and move through the holes into the attic.
Additionally, we create a lot of penetrations in our ceilings for such things as lights and fans. Warm air will flow through the gaps and cracks surrounding these penetrations into the attic.
You can test this theory using incense sticks around these openings and note that smoke will travel into the attic space above.
Compounding the issue in many older homes is the fact any insulation in the attic is either a “loose-fill” or a fiberglass batt, both of which will allow air to move through them.
Remember, The Guys always suggest thermal insulation products that not only slow the transmission of heat, but also stop the movement of air.
Those old batts in the attic allowed so much air to move through them that they would turn gray from the dust particulate they trapped as the air was moving through. They acted as air filters for all the warm air from below escaping into the attic.
When air can move into your attic and through the insulation, you have the makings for the scenario we discussed at the beginning of this article.
The Guys have many times witnessed an attic space where the nails holding the shingles in place are coated in ice. This moisture came from the living area below and should have been exhausted through the attic vents. But when extremely cold conditions exist that warm, moist, air quickly loses its heat, and the moisture will condense on the coldest available surfaces like nails and the underside of the roof deck.
When the outside air warms a bit from a sunny day or rising temperatures, the ice will melt and fall back down on top of the ceiling insulation.
This cycle can create dry rot conditions in the attic and possibly provide an environment for molds to flourish.
So, what can you do to prevent this? Seal your ceiling plane. You often hear the Guys talk about limiting ceiling penetrations, but many can’t be helped. The alternative is to provide air-tight seals around all penetrations, then insulate from above to stop heat movement.
Companies like Ace and Sons Insulation in Southgate and Amistee Air Duct Cleaning and Insulation in Novi can provide professional sealing prior to an insulation install.
Steve Dickinson from Amistee says he has been in a home with 150 recessed lights. Whether those were 4-inch or 6-inch diameter cans, it doesn’t take a lot of imagination to consider how much air could move through those openings.
One potential result of providing this service in older homes with damp basements can be a sudden increase in the indoor humidity to the point of condensate on the windows. Increased sidewall insulation and improved air flow throughout the home and duct system can minimize this, as can application of sealing materials on basement concrete wall and floor surfaces.
Take steps today to stop the formation of weather patterns in your attic. Have a professional seal your ceiling and install a quality insulation product. Your home will thank you.
For housing advice and more, listen to “The Inside Outside Guys” every Saturday and Sunday on 760 WJR, from 10 a.m. to noon or contact us at InsideOutsideGuys.com.