My family room has a painted T&G wood-planked vaulted ceiling that leaks air
I have a question about an effective way to solve an issue in a house with a large family room that has a painted T&G wood planked vaulted ceiling that leaks air and makes the house very cold in the winter.
The T&G pine paneling is nailed to the bottom of the roof rafters and there is no finished drywall behind the paneling to create and effective air barrier. The rafter roof assembly is vented with vented soffits and ridge vents and R19 FG batts. The first option to weatherize this ceiling that I feel most comfortable with is to take down the paneling which would allow me to inspect the insulation and then install finished drywall and put reusable or new paneling back up to insure a tight air barrier in the ceiling. This fix would be fairly extensive and I was looking for some options that would be effective and less costly. We discussed caulking all the seams?, drywalling over existing paneling and putting up new paneling or taking down paneling, removing FG batt vapor barrier and putting up CertainTeed Membrane instead of drywall for air and vapor barrier and reinstalling paneling.
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Replies
Bruce,
There is no cheap way to fix this ceiling. You have no air barrier -- your ceiling leaks lots of air -- and the R-value of your ceiling is below minimum code requirements for all climate zones.
You can work from above by adding at least R-20 of rigid foam above the existing roof sheathing -- an approach that would require new roofing, and would require you to seal the ventilation openings at the soffit and ridge.
Or you can work from below, by either removing the existing board ceiling and starting from scratch, or by adding at least R-38 of rigid foam on the interior side of the boards (assuming that the effective R-value of what you now have is about R-zero) plus a new ceiling.
Either way, the work won't be cheap.
HI Martin, Thanks for responding. I figured that I would have to start from scratch from below. I am trying to give my homeowner, who is a close friend, some options to choose from. He just did recently put on a new roof with 50 yr. shingles so I did not want to suggest an option that involved tearing the roof off. I know his biggest concern was what to do about the heat loss in house from air leakage through the vaulted ceiling. Once we determine that step we could then determine what options were available for further insulation. As always cost, time and renovation mess is part of the equation. There also will be other comprehensive weatherization measures performed throughout the house. I am still not sold on the longevity and VOC's of spray foam in a full vaulted ceiling rafter bay creating a hot roof, although there is no other way to get R49 in a 2x10 roof rafter bay cavity. Thanks again Martin for your feedback. Bruce
Bruce, sounds like you're in a place I have found myself a lot recently: a contractor hired to triage and improve energy efficiency in an already-built home. Everything conspires to complicate the process: client preferences, existing poor construction, money, mixed climate, differing opinions on GBA, etc. etc.
Martin's foam options are the best ones, but they may be too troublesome from an aesthetic standpoint, never mind the possibility that the ROI for this job (expensive foam and professional installation) is probably way too long. Spray foam is effective but the point is made here repeatedly that spray foam fully between rafters is too expensive to be so badly compromised by heat bridging. Membrain instead of drywall is not an air barrier. Use a blower door to locate the worst cracks and caulk them. If the ceiling isn't showing obvious water or vapor damage, it could be that your homeowner's energy efficiency dollar is better spent in the basement below or elsewhere in the house.
Bruce,
If the budget is tight, the easiest way to proceed is to give up on the T&G look. Simply install as much rigid foam as you can afford on the interior side of the existing board ceiling, followed by drywall.