Vapor Barrier - 6 mil or 4 mil?

I have a question about the vapor barrier that I am going to place against my concrete block foundation wall. The poly that I have right now is 6 mil. Should I return it and exchange it for 4 mil poly? I live in Minnesota.

Thanks,

NBL

 

NBL,

This should you help you right out as I am from Minnesota;

Vapor barrier should be placed directly under the drywall. The warm inside air containing water vapor can get past the wall finish and insulation and condense inside the colder wall cavity. If enough of this happens, and the water cannot escape, wood rot, mold, and other moisture-related problems are likely to occur. For this reason, building codes often require installing a vapor diffusion retarder on the warmest side of the wall cavity. This is what is required in Minnesota;

"A 4 mill poly vapor barrier must be placed against all concrete or block exterior foundation walls prior to applying furring strips for full height of the wall. Another 4 mill poly vapor barrier must be placed over furring strips and insulation prior to covering with finish materials. (State Energy Code Requirement)" - MINNESOTA CODE

***WHEN HANGING VAPOR BARRIER OVER THE CINDER BLOCK, IT IS NECESSARY TO CUT HOLES OF SLICES AT GRADE LEVEL FOR WEEPING***

Hope this helps!