As far as gluing the floor down (engineered flooring only) I just put one down a short time ago and the customer bought the glue and it is "supposed" to form it's own vapor barrier. Ran him about $100 a bucket this is the first time i used it so don't know how it will hold up. This was on a slab here in fla. maybe go to a flooring store, NOT a big box store and you can find out about glue down. Here in fla everything is on a slab so they sell a ton of this stuff and tell me they aren't getting any call backs. Maybe check it out.