Dealing with Humid Apartments & Vapor Retarder/Barriers
There appears to be a lot of takes on the necessity and science behind poly vapor barriers being required on top of studs over batt insulation. I've read the building science documents and some other documents and all seem to say, in short, Class 1 vapor retarders/barriers such as poly are not to be used on the interior side in areas that are not extremely cold. The documents even say that poly on the inside should not be used if the room ever plans on being air conditioned. And the recommendation is to make sure to prime and paint the drywal with a few coats which in and of itself creates a class III vapor-permeable barrier and use the appropriate R-type insulation to control heat transfer.
I'm dealing with an apartment on a second floor of a home built about 80 years ago. It's brick, two layers of brick actually -- no type of insulation on the outside or spryaed in between the bricks. The house in in Queens, NY, which i believe is classified by building science as zone 5. It's a mixed climate, with the actual heating days consisting of about 5 months (November through March) And air conditioned days falling between May through September. Personally, April and October fall right in between, again, in my opinion.
This particular apartment generates an enormous amount of humidity, so much so there is a generous amount of condensation on the windows in the winter months. I'm renovating the apartment and noticed the insulation is black and wet, the window sills were rotted. Obviously the humidty passed through the drywall and settled inside the wall assembly into condensation and generated mold. After reading that poly barriers are not recommended on the inside wall assembly on top of studs -- what would you do in order to prevent the vapor/humidity to be generated in this apartment from damaging the new wood and insulation i plan on installing?
Taking into consideration I try to limit air leaks and exhaust as much from the kitchen and bathroom.
Putting up new framing, new insulation only to experience the same issues seems futile, hoping you guys/gals have some helpful advice/feedback.