Interior air sealing and tongue & groove in weekend cabin
Zone 3, central/south Georgia hot/humid climate 300 sq. ft. weekend cabin with wall unit a/c, on piers (2×10 joists w/R30) with 2×6 stud walls; R19 fiberglass batts; good attention to caulking all seams/cracks and can spray foam around windows, door, penetrations; 1/2″ plywood sheathing, 1/2″ Rmax; weathermate plus housewrap, then finally cement board siding. Toilet, shower and sink with vent through the exterior wall. This will be a weekend getaway place – not lived in for more than a few days at a time. No washing machine.
Question: Would we be potentially creating a problem by installing a layer of weathermate plus wrap behind the T&G pine planks? Trying to save a few labor dollars and not going with the full airtight drywall approach then attaching the T&G to the drywall. Would there be another option for behind the T&G? Or, under our circumstances of this being a weekend place, just attach the T&G to the studs and understand it won’t really matter.
Thanks in advance, Mr. Martin. You replied several months ago before the project got underway; I’m now ready to finish the interior and need your – and all other – comments.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
Brad,
Drywall is the tried-and-true method for making sure that you have a good interior air barrier. Plastic housewrap would probably work, but probably not as well -- in other words, it is likely to be leakier. If you do decide to use plastic housewrap, you should invest in tape to seal the seams and penetrations.
Another possibility is an interior air barrier that comes in a roll, like Intello membrane.
Thank you. Understood, the DOW Weathermate Plus will allow some airflow/infiltration behind the T&G, as opposed to the drywall method you have referenced on multiple occasions. My biggest concern was potentially creating a mold growth 'chamber' behind the T&G. Also considered #15 or #30 felt, however, thought there might be a tar smell after the cabin had been shut-up for weeks then reopened. Thanks again and for taping the seams tip.