Vapor barrier over/ under scribed sleepers on concrete slab
We have an out of level slab by over 1-1/2″. We plan on gluing and screwing scribed sleepers to the concrete, applying a 6 mil poly vapor barrier over the sleepers and then screwing plywood to the sleepers and installing engineered flooring material. There is foam and a vapor barrier under the slab. My question is if I put another vapor barrier over the sleepers… will this trap moisture since there is one already under the slab? We can’t install EPS or foam board because the floor varies so much and spray foam is cost prohibitive and probably unnecessary since we have foam under the slab.We can install the vapor barrier under the sleepers but this relies on the screws (tapcons) to hold the sleepers and I feel better with an adhesive for added strength and to avoid squeaks.