Insulation, Radiant and Vapor Barriers - Cellulose insulation & vapor barrier?

My husband and I are building a new home. We had cellulose insulation blown in the walls on thursday. The dry wall guys are asking where the vapor barrier is. The insulator says it is not needed. Is this true? Dry wall guys are at our house again today. Need help quick! Thanks

A vapour barrier is always installed on the warm side. Without it, moisture will get inside the wall cavity and then rot/mold will occur.

What did the city inspector say? I assume your contractor has gotten a permit for the construction.

Before you pay, get something in writing from the applicator that says the insulation is a vapor barrier and prevents air leakge between the studs and insulation.

Some of these systems have conflicting claims.

Dick

My husband and I had the drywall guys sheet over the cellulose withOUT the vapor barrier. Checking with the building inspector would have been a much better idea. I also didnt get anything in writing. We are the builders on our house (1st house) and we did get permits. I sure hope the building inspector passes us. Thanks for the advice. I waited too long before asking this question. Everything moves so quickly. I'll reply and let you know what the building inspector said FYI Thanks, MOMO

Oh oh, I hate to say this but, if you got the permits, then an inspector would have wanted to see how the home was insulated before drywall. That is one of the many inspections required by the city. I hope you won't have to tear down the drywall for him to see the insualtion.

I sold and installed cellulose insulation for many many years. You do have to have even a 2 mil poly or more for a V/B. Have seen jobs where no V/B there and the drywall will like cup down or out.

ED :wall: