We just bought a new house which needs extensive remodeling.

Our contractor, after ripping out the existing old carpet and damaged subfloor/padding, discovered that the floor was quite uneven, so we had an idea to install floated flooring for the hardwood (strand bamboo) that we were planning to replace the carpet with.

Can anyone suggest the pros and cons of the floated flooring approach?

  • 4
    Why will a floated floor help? Won't you still get hollow sound and fell (or even bounce) in the areas where the subfloor dips? Sep 30, 2010 at 9:55
  • 1
    Just how uneven is 'quite uneven'? Most guidelines I've seen call for no more than a 1/8" variation over a 4' span. In one installs I've did, we had to do a combination of shaving where the subfloor was uneven with a chisel, some belt sander time, and a few treatments of floor leveling compound.
    – Joe
    Sep 30, 2010 at 18:11
  • Vebjorn, I think another reason the flooring installer recommended float was that we were interested in solid strand bamboo which is very hard (Janka 3300+) and difficult to nail, and glue is expensive.
    – r00fus
    Oct 1, 2010 at 5:26
  • Folks, thanks for providing input. My contractor (not the flooring installer, per se) was worried about the time it would take to properly prepare the floor (he's on hourly and we have a firm move-in date) and even it out... but given your answers, I think I'm going to have him spend the time to do it right.
    – r00fus
    Oct 1, 2010 at 5:27

2 Answers 2


My thoughts? EEK! I think this is a recipe for trouble. I hope this was not suggested by the contractor?

These floors need smooth surfaces underneath, with underlayment that will support the flooring. If there will be serious problems like that, they need to be fixed before you put down flooring. Otherwise, you will have flooring that flexes every time you walk over a spot. You will have loud squeeks. The joints between the pieces will open up and close, allowing dirt to lodge in there, unsightly lines will appear in the flooring. With enough flexing, the hard surface coating on that flooring will start to crack.

While padding is used underneath these floating floors, the flooring is simply not stiff and strong enough to resist the flexing I am talking about.

Do the job right the first time. You don't want to tear it out and redo it later. If the cost of repairing the subfloor is too much, just replace the carpet.

  • When you recommend "replacing the carpet" ... the carpet that was in place was probably 10+ years old and completely worn out, so we'd have to put in something new. Are there other ways to compensate for the uneven floor with other underlayments (ie, plywood + shims)?
    – r00fus
    Oct 1, 2010 at 5:29
  • I will admit that we have one spot in our 25 year old home that feels uneven through the carpet. The previous owners extended a bedroom a few years after it was built, and in that spot the floor now has a problem. You can feel it. A good flooring contractor will lay down new plywood. If there are holes and other divots that need to be patched, they would fill them. One option is a plaster-like leveling compound. In extreme cases where thin plywood will not be sufficient to solve the problem, a contractor will probably suggest pulling up the subfloor and replacing it with a new subfloor.
    – user558
    Oct 1, 2010 at 10:35
  • 1
    In the case of a subfloor that moves, is loose, it MUST be secured first. Nail it down, or replace that section of subfloor. In the end, you really want a nice smooth surface, as any problems will telegraph through. Carpeting, usually laid down over a pad (a high quality pad will extend the life of the carpet, and is relatively cheap) is surely more forgiving of minor flaws. But even carpet wants a good surface underneath.
    – user558
    Oct 1, 2010 at 10:45

Our house is on a slab foundation, and has floated flooring in a large part of the house.. The previous owners had the foundation repaired at some point, and while it may be better than it was before the repair, there are still places with noticeable flex in the flooring. Do not simply install a floating floor material over a non-flat surface.

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