Wood Floor on Slab

18 months ago we had to replace a parquet floor that was put on 1/2 plywood over a slab. The floor was termite damaged. The installer glued it to the plywood, it never had any mildew damage after 25 years. This new floor is engineered wood and started to buckle and discolor in a few spots. After haggling with the floor mfg. went nowhere the installer agreed to replace it for free. Today he started removing it and found a few planks that had discolored, they had patches of mildew underneath. I asked him if he used a vapor barrier as stated on the invoice. He said he sprayed it on like they do to waterproof basements. My invoice says " Eternity Pad".
Now he says he will give me free labor but wants $1200. for the new flooring.
My question is would that pad have been installed over the slab or on top of the plywood. I didn't see any thing under the flooring he removed that was nailed down.
This is a 150 sq. foot floor in the foyer and hall.
thanks

 

my experience is that for engineered hardwood, the vapor barrier goes on over the concrete slab and below anything else

Builders Direct has good free info

 

All the proper install directions should be right on the manufactures web site.
If you do not follow them to a tee there is no warranty.

 

No wood direct contact with slab be it plywood (no,no) or the wood itself. Instead look into a floating floor with moisture/vapor barrier underneath.

 

For $8 sf for flooring alone, I'd tell the installer you will furnish the flooring and underlayment. Since there was moisture damage, I would do a moisture test before I installed any wood product. Is this below or on grade?

 

Thanks for the replies. Rather than remove the plywood, the contractor used a pink paint to seal the plywood than covered it with tarpaper. It happened in only a few spots.