Hello everyone, new to the board. Just bought a house, moving in at end of the month and looking to update the floors. The first level currently has engineered hardwood glued down on a concrete subfloor. We are looking to put down new solid, handscraped hardwoods. This normally would require removing the existing engineered floor and nailing plywood to the concrete subfloor, then the hardwood planks to the plywood before finishing.

It has been suggested, to avoid the cost of removing the glued down engineered wood, that you can nail a thinner plywood sheet than normal (in order to be the normal height when finished) directly through the existing floor into the concrete. Then the hardwood planks into the plywood, on top of the existing floor.

Any opinions on this? Good or bad idea?

Thanks.

The problem you may have is moisture coming from the slab and getting trapped between the old hardwood floor and the plywood. The hardwood floor stuck to the slab may be acclimated now, but with new plywood on top it may swell some, creating a problem. You would be trusting that a moisture barrier was installed under the slab in the beginning or under the first hardwood floor before it was installed. Do you want to take a chance?

I don't see why not as long as you incorporate the same moisture protection as one would with a traditional plywood sub floor over concrete. The ultimate protection could be using a trowel spread barrier with the plywood.

Thank you for the responses. To add a little more context, not demoing the existing Engineered Wood would save me about $1,700. So total cost for the job would be $6,300 versus $8,000. This is part of a larger renovation budget of approximately $25,000, which will include new countertops and carpet.

The existing engineered wood floor has been installed for many years. Just weighing the risk versus return of saving $1700.

Maybe too late to the party here, but no one mentioned warranties - if you install the new product over the existing engineered floor, you will void your manufacturers warranty. Even if the new wood is noticeably defective after installation, the manufacturer rep will wash their hands of the concern since you did not follow the correct installation instructions. Your contractor would be smart to make you sign a waiver absolving them of liability as well - I know I've been asked many times to install over some existing product and my answer is always the same, 'not without a waiver'. Like Pete said, do you really want to take a chance? If you do the job right, you're out a couple grand, but if you take a shortcut, it might end up costing you the full thing to have it replaced properly - and the second time around, you'll not be looking to cut corners will you?