Plywood under wood floor on slab foundation?

marti8aMarch 6, 2012

We're getting ready to add on a dining room, and are doing a little kitchen remodel at the same time. Kitchen has 8 inch white tile, in fair shape but dated.

We had engineered wood floors put down in living room several years ago, and it is not holding up well.

I've been looking around at floor options for the kitchen and dining room and the smaller flooring stores have been telling me (for wood flooring) that the flooring will hold up better if it has a plywood layer under it.

NO ONE locally told us that when we put the engineered floor down. We are in central Texas, and a friend in NC whose husband does repo repairs said it is common there.

So, is it necessary? Is it better? Worse? Why?

Thank you for reporting this comment. Undo

That has been a common approach here when homeowners want to put down solid wood on slab. However, 10 years later when it's all rotted out from the moisture migration from the slab, they usually have learned their lesson.

The new addition should be constructed with a vapor barrier under the slab, but the old one probably wasn't. That makes using the same flooring a bit more problematic, as well as the potential for levelness issues between the two structures.

Unless you're putting down pressure treated marine grade plywood, just using a good trowel on vapor barrier and gluedown engineered wood flooring is sufficient. Or you can do a floating floor with a vapor barrier under it, which might be the better approach since you are wanting to do the same floor in two separately added home sections.

    Bookmark   March 7, 2012 at 10:24AM
Thank you for reporting this comment. Undo

The house was built in 1983, but not by us so I don't know if it has a vapor barrier under slab or not. The house was wrapped with a barrier, so maybe.

What is the name of a trowel on vapor barrier? Is it thick like thinset, or more like glue?

    Bookmark   March 7, 2012 at 12:00PM
Thank you for reporting this comment. Undo

Get a real RH reading from your cement. That will determine the facts. Then if RH is fine...use a urethane (top quality adhesive) and glue down and roll an engineered floor. I assume there has not been any movement. With that said, I would like to hear more about the engineered not holding up...what that statement means as that could have a further bearing on any advice given.

    Bookmark   March 8, 2012 at 9:07AM
Thank you for reporting this comment. Undo

Yes, a reading was done before the first floor and was ok. We have had some movement in the foundation but not at that end of the house.

I think the problems are partly because the flooring wasn't acclimated before being installed. It was in December, and the flooring was brought out here and installed the same day. I don't know where the flooring had been stored before it was shipped to the floor store, or how long it sat in their warehouse before being installed.

It is a Mannington Hickory, and at first it was just checking, but now we have a hump where it is no longer glued to the floor and raised up.

After the checking, I posted and other people posted about the same problem with that floor. The floor store owner came out and said it was a problem with the floor. Mannington sent a rep out and of course it wasn't the fault of the floor, and then the floor owner agreed with them. So we were the big loser there.

And we wanted to buy from a local store so we wouldn't have any problems. Next time we do it ourselves.

    Bookmark   March 8, 2012 at 11:17AM
Sign Up to comment
More Discussions
Natural hickory...yes or inside
I got a sample box and put it out on over the carpet...I...
Handscraped hardwood -- will it become dated?
So we are in the process of building a new home. We...
Water-based finish over dark stained floors?
Hi all, Folks are about to start flooring work on my...
Flooring for road noise - Carpet or LVT
Hi Everyone, We are looking into replacing our entire...
Suggestions for Beach House Flooring
Building a 2500 SF house and 500 SF carriage house...
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™