Hardwood on slab (not basement)

I was looking to install engineered wood in 2 rooms of my townhome. The floor is a concrete slab, no basement, and the slab is not below grade. A contractor actually said they could install oak provided a vapor barrier was put down directly on the slab, then a plywood subfloor (not sure of thickness) was laid down.

Does anyone see problems here? I alwasy thought that hardwood on any concrete was not a good idea.

Thanks,
Todd

 

As long as there are no moisture issues (and above grade is certainly a good start), wood can be considered. I think your contractor is on the right track.

 

I'm not understanding why a plywood subfloor would be needed for an on-grade installation over concrete. Engineered hardwoods are specifically designed to be installed over concrete. Why not purchase a good quality engineered hardwood and float it over the recommended underlayment. This is usually some type of foam or rubberized felt.

 

I agree with staabc (Mitch, too), the modern click lock 5/8" or so thick engineered flooring goes down solid and feels that way on a proper underlayment. No click-clack, no "give". I don't think there is a need for the plywood. Besides how will they fasten the plywood to the concrete?? Nails Holes in underlayment rendering it useless. Lay the underlayment, lay the click lock and enjoy.

 

Thanks all. I thought that the entire process seemed a little strange. Once the plywood is attached to the slab (nails I'm assuming) the vapor barrier would be useless.

There is one potential problem. There is only 1” clearance between the slab and the top of the door jamb/front door weather strip. This actually applies to the front door and garage door. The subfloor and hardwood would at 1.5”. This contractor claims he can cut the wood at a 45 degree angle so the door clears it. Does this process sound familiar to anyone? I keep picturing a slope at the front of the house.

From a pricing standpoint (including installation), do you see the engineered material more or less expensive than the oak hardwood?

Thanks again.

 

If you install engineered flooring with a vapor barrier, the 1" clearance will become moot. You will only be taking up less than 3/4", leaving a piece of molding against the door jamb/wx strip.
If the contractor's theory is to install 1/2 or 3/4" plywood, underlayment, then 3/4" wood flooring in a 1" space, he needs a new ruler. I am not sure what he means by cutting it at a 45 degree angle. The last Piece? All the pieces in the swing area of the door? Not likely. Run.

 

Thanks Chandler...I thought the slopping factor seemed a little sketchy.

 

If your still worried about a vapor barrier, check out a product called "DRIcore" (DRIcore Subfloor Basement Flooring Home Page)

 

I'm assuming, he wanted to nail down a solid over the plywood subfloor, the sand and finish it.
He was in the up-sale mode.


Apply a moisture barrier like Bostik's MVP-4 and use their BST, or BEST adhesive
or
Mapei's WFM PlaniSeal moisture barrier and use their 980 or 990 adhesive.