Is it necessary to caulk between drywall sheets in an attic floor if it is plaster over drywall?
user-978162
| Posted in Energy Efficiency and Durability on
My question is it necessary to caulk between drywall sheets in an attic floor if it is plaster over drywall? I know one always wants to do this when it is just drywall because tape and mud allow for too much air infiltration so good practice is to caulk between drywall sheets. It seems that if there is plaster on the other side of the drywall this would not provide much added air sealing. Am I correct in that assumption?
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Replies
Kyle,
It sounds as if you are performing air sealing work from above, and that you're working in an uninsulated attic.
You are correct: if you have plaster ceiling, and there is a layer of drywall (or, more likely, rock lath) on the exterior side of the plaster, you don't have to caulk the seams between drywall sheets or rock lath sheets.
Concentrate on the gaps between the wall finish materials and the partition top plates, as well as electrical penetrations, the plumbing vent stack, and register boots. Don't forget to install weatherstripping and a couple of latches on your attic access hatch.
-- Martin Holladay