Hello,

This is new construction. I had the concrete slab poured 1 1/2" below floor level. I used a product called "Foundation Armour" to seal the concrete. I intent to T-nail 1x4 PT furring strips to the concrete. I will use "Liquid Nails" and screws to secure the plywood to the furring strips. I will staple 15lb felt paper to cover the plywood and install 3/4" redwood oak flooring (not manufactured) as the finished product.

I would appreciate any input you may have on this process, like do I really need to use PT plywood, type nails, etc. My main concern is moisture. I live in Florida, the slab is on grade, and I have excellent drainage with no rivers or other bodies of water nearby. The sealer I have used is sprayed on the concrete. It is lithium silicate which is supposed to react with the free calcium and natural lime to form a crystalline structure within the pores of the concrete. This results in filling the capillary tracks thus rendering the concrete waterproof. I'm a bit skeptical about this and wonder whether I should use add poly-sheeting on top of the concrete just to be safe?

I fell it's great to have an expert to help us DIY's. Thanks.

Tim