I am a homeowner and have had my very first new engineered floating hardwood floor professionally installed in kitchen area, and new kitchen cabinets installed overtop of the floor.
Old floor was lino over underlay, the contractor removed the underlay and the floor was applied directly onto the 5/8" subfloor after some "sanding". Underlay was a green foam like material , possibly 1/8 to 3/16 thick.
The finished floor drops nearly 1/4" in one area when walked on, in a span of about 2 feet, it is a bit "crunchier" here also.
I put a 3' straight edge across the affected area and the hardwood is flat until stepped on, it sinks in a dish when weight on it.
It appears there is probably one floor joist a bit high causing this problem, the hardwood is bridging the unlevel subfloor on the sides of the high joist.
This was not felt with the original lino floor as the original underlayment appeared to have been leveled with a cement like product.
The balance of the new floor seems acceptable, probably moves 1/8" under-foot or less, but generally feels solid.
I feel this amount of movement is unacceptable, what is the industry standard? I could have done a better job installing it myself by levelling the affected area.
I am not on site when all work takes place, the general contractor is in control of all the trades.

like you said "the original underlayment appeared to have been leveled with a cement like product"
if that was so it should have been put down to make it level in that place again. the floor can be popped up and fix in the area and put back down.
a nice trick is to use sand. it's dry and you dont have to wait for it to dry or shingles too.

Jeff

I would have probably left the old floor in place and gone over it. The reason? It made the subsurface stronger with the underlayment and had less flex. Some contractors do not think. Another issue is installing the cabs on a floating floor? Especially a laminate? that's a no-no. I think whoever is responsible should probably redo it.

The cabinets installed over top of the floating floor was the contractor's decision.

If the floor is a "Uniclic" system, it is easily removed back to the area of questionable sub-floor, then use sand or shingles as Jeff suggests, or alternatively we usually use cork underlayment, comes in varying thicknesses to make it easier to level out problematic areas.
If a glue together t&g floor, better idea would be to drill a 3/32 hole through the floor in the low area, and inject epoxy. Note that this, while acceptable industry practice, may not be acceptable to you, and you need to consider how it may impact on the longevity of the floor

Z, I'd have to agree with Gary......sounds like your GC needs to have the floor redone.
(1)Depending on how much deflection you have in the low area, you may never have a structural problem but the likelihood is that eventually you'll get joints separating there.
(2)With the cabinets installed on top, your floating floor is no longer floating...with the floor locked in at the cabinets, you're probably going to see some bowing, separating, or both.

Short of replacement, they need to at least cut out an expansion gap at the cabinets and install some molding to cover the gap.

Floor does click together, but it will be a bit tough to take apart as there is a U shaped kitchen screwed down on top of the floor now.
Floor contractor claims the general contractor levels the floor, too bad neither of these guys detected this condition. I am starting to feel sick over this.

Well you have every right to having a floor that performs properly, and this is an aspect of a properly levelled sub-floor. Stick to your guns and have the floor removed and re-installed correctly, including proper expansion around the cabinets.

All things considered I would have the floor replaced and installed properly.

Guys, let's keep in mind, it's a kitchen and most are under 150 sq.ft. Also, it's a laminate. We know those are not expensive, compared to hardwood. So, the general contractor should be able to redo this without too much financial pain. Let's see what a general contractor's reasons would be to install the floater first. All I can think of is to avoid having to trim out the bottoms of the cabinets. There is no other advantage to the GC.

I understand your point Gary, I'm not one to throw someone in the river without thinking it through some. I should have asked questions but my take is that we are talking about a wood engineered floating floor installed over FloorMuffler. The poster referenced some cabinets are screwed through the floor. To me that is an island or peninsula cabinet situation and it would be very unlikely that cabinet was situated where one could cut out all round it without leaving too short butt joints, and or, rips on one or both sides of the flooring.... possible yes, but that would be an accident. A click floating floor needs to maintain its integrity in every single row for it to all stay together.

We are both in agreement. The floor was improperly installed. For some reason, I thought it was a laminate. I must have just read Ken's question re: laminates still here and what we all thought of them. I still cannot understand why a general contractor ( not the flooring contractor ) would want and choose to have the floor installed first; especially a pre-finished. That requires the GC and the other subs to be so much more careful. I just cannot see it.

So far suggested fixes have been to screw it down solid where it drops, or wait till fridge is set on floor to see if improves things. First item I won't allow, and just tried the second without success as the new fridge finally arrived. Looks like a redo of the affected area is in order, failing that I will subtract the cost of the floor from the job, paid about $13 a square foot for this installed, total area around 230 square foot, nearly 1/4 of that is under cabinets now. There are some marks on the floor already from from the 2 -3 day kitchen install, and there is probably another week yet till everything complete. I was going to continue with hardwood in the rest of the top floor but am leaning towards carpet now.

This is interesting. Since you going to have to cut around the cabinets to get it out anyway, just cut it and add trim. The floor is most likely trying to expand causing the verticle movement.

13$ sq/ft ??!! You should definately have it re-done. Level the subfloor, install around the cabinets. For that price, they should know what there doing, or at least make it right. Good luck.