Vapor Retarder for Three-Season Room
Toolman2957
| Posted in GBA Pro Help on
Hi , I have a 3 season room I built onto my Park Model in Wi. I have it insulated with Rock wool with OSB and house wrap on outside. Its only heated some times in late fall, spring and sometimes in winter for the day. I will be putting shiplap osb coated white boards on walls. Do I need a barrier?
Thanks
Bruce
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Replies
At a very minimum it needs a somewhat vapor retardent interior side AIR barrier.
Half-inch OSB is sufficiently low-permeance (it's about 1 perm when dry), but it has to be detailed as an air barrier. The seams need to be caulked &/or taped, and only air-tight electrical boxes should be used.
Painting OSB with a standard interior latex primer lowers it's permeance a bit too, all worth doing.