How do I prevent condensation on my new open beam ceiling?
I am a general building contractor and built a custom single level home comprising of an open beam cathedral ceiling with 2×6 T&G sheathing under 4” Ridgid Foam insulation under 1/2” plywood sheathing under Mission Tile style roof. The air space between the T&G and the plywood is filled with rigid cellular foam insulation.
Building is located in a beach community in Southern California where temperatures are relatively mild between 65-80 degrees 80% of the year. The building has under floor duct work for both heating and A/C.
My problem is when the temperature exceeds 85 degrees the ceiling ridge beams start to sweat and drip.
I have installed a dehumidifier as part of the HVAC which consistently expels water into an outside drain.
Any suggestions to help with correcting this problem would be apppreciated.
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Replies
Where is your air barrier? Is it the foam? Did you tape the seams of the air barrier layer?
It sounds like conditioned air from the AC is meeting unconditioned air at the roof peak.
User-7110790 (by the way, it would be a good idea if you would tell us your name),
Wow! We're getting a lot of these reports these days!
Here is a link to a similar thread -- read my long answer there: "How do I fix condensation between ceiling and closed cell spray foam insulation?"