Solid Hardwood, Engineered and Laminate Flooring - Noisy floating floor

I just had a floating wood floor (Kahrs) installed in a brand new house, over a concrete slab. Since the installation, the floor makes very annoying cracking noises in lots of places when you walk on it , and there is noticeable flexing of the wood in some areas. The noises are worse early in the morning, maybe due to temperature differences. The installer claims this is normal, but I'm not so sure. Is this normal, and is there some way it can be remedied without re-installing the entire floor ( a very expensive proposition)?

If there is noticable flexing, and it makes "cracking noises in lots of places when you walk on it", and it is installed on a concrete slab. It brings to mind a few questions.

Did the installer...

Make sure the slab was level, and not "wavy"?

If it wasn't level, did they take steps to make sure it was leveled. (you would know, because they would have charged you extra for this, if they were aware of it.)

What kind of underlayment did they use?

Kahrs is a floating floor, but the planks are glued together at the seams. Perhaps the amount of glue he used wasn't in proportion with the manufacturer's standard glue spread?

All questions that should be addressed when talking to your installer.

No, they didn't level it. I asked before they installed if this was necessary and they said no, because the builder would haved ensured that the slab was level in case they had to install a wood floor themselves. I assumed they knew. The underlayment they used was some sort of plastic with pieces of embedded foam which was made by Kahrs also. They coated the floor with something called Deco-Rez and charged me extra for that at the last minute because they said the slab had too much moisture.

Even though Kahrs is a manufactured (engineered) wood laminate, with better dimensional stability than solid wood flooring. It still is prone to warping, and other problems, if the moisture level is too high. You didn't mention the moisture problem in your first post, or I would have mentioned it.

Your installer should have held off on installing your flooring until the moisture problem has been resolved. The coating that they applied may not have been a sufficient moisture barrier.

Of course, making sure the slab was level would have been a good thing to check also, in any case.

Moisture could in fact be the problem. A newly poured slab of 4" thickness can take 16 weeks to cure down to a satisfactory moisture content for wood flooring. Is this Kahrs glued together or is the Linna glueless and was a moisture barrier of 6Mil Polyethylene put down first? Level is second behind FLAT. Did you visit the job site while the house was under construction and did you see puddles of water on the freshly poured slab? Usually the slab is kept wet for a few days after the pour and low spots hold some of that water. What is the climate where the home is located and what is the method of heating.

Aside of what others have mentioned another reason could be the glueing method. Although it's been a few years since I've dealt with the Kahrs product, they are very similiar to that of Harris-Tarkett. BUT, both have different methods. Kahrs recommends glueing the entire groove, whearas HT calls for 8" glue beads every 10" or so.

There has to be a very good reason for the difference and perhaps the installer used the HT method, which could cause the cracking noises?

Well thanks for all the info. anyway. I assumed that the slab should not have had a high moisture level since it was laid well over five months ago, but the installer used a moisture meter and showed me that it read "8" which he said was well over the limit. I'm not sure what units were used in this reading, and I had some suspicion that maybe the meter was 'fixed' so that they could charge me another $1000 at the last minute for the moisture barrier.

If your installers moisture meter said 8, that is certainly an acceptable level. If the moisture level between the floor and the Kahrs laminate is within at least 3%.

As far as the installers meter being "fixed", to milk more money out of you?.........

Gosh, I certainly hope not.

Some warrantees will not allow more than 2.5% moisture in the sub floor. Your '8' may be a real problem. It is if it's 8% moisture. The concrete dries Very, Very slowly.