I had a bamboo floor installed on an above grade concrete slab. They used the manufacturer recomended glue wich was also a vapor barier. About a month after installation it started to cup and lift from the glue. I have been through months of representitives of the glue and flooring manufacturer coming to look at the floor to determine what was causing the problem and who is at fault. The flooring store is now replacing it with a floating floor. When they were pulling up the floor there was moisture between the flooring and the glue BUT NO MOISTURE BETWEEN THE GLUE AND SLAB. I also notice that the spacers around the wall were never removed and couldn't be removed by hand because they were wedged in there. What would cause the moisture between the glue and the floor? Nothing has ever been spilled on the floor and I've never "wet mopped" it.

I bet them reps are all dumbfounded. lol

First of all how could you ascertain there was moisture between the glue and wood if the glue was stuck "percentage wise" to the wood flooring like it should be...90 - 100% coverage?

Next, I am sure the installer is going to bite it for leaving zero expansion space having the spacers left in there. Duh

And a combo glue/vapor retarder to boot! Awesome, who's was it? Ya know the public would never hear about those newer adhesives that are combo having problems unless people like you tell us. But coulda been those rascally spacers in there causing the floor to lift.

It doesnt really matter at this point looks like the store is stepping up and taking care of "their" problem. Be thankful that your working with a reputable outfit. What the inspection report say or did you even see one.

Although there is a lot of finger pointing between the installer, glue and flooring manugacturer the I am very glad I went with a very reputal flooring store and have nothing but good things to say about his willingness to make things right. But I am very concerned about were this moisture came from. When the installer removed the glued down floor, there was an area that had seperated from the glue. That is were we saw the moisture between the floor and the glue. It was very obvious and you could see beads of water. The glue was still stuck to the slab and when it was scraped up most of it came up in large pieces and although the top side of the glue had the moisture on it, the bottom side was completely dry and so was the slab. The remainder of the floor problably 90% glue coverage. So I am trying to find out were this moisture is coming from.

I may have been using the wrong word when I said the glue was a vapor barier. The glue that was used was DriTac 1001 Moisture Cure and from what i was told was also a moisture barrier. It definetly seemed to work as a barrier because there was no moisture on the slab side only the bamboo side.

Could it be that because the spacers were never removed the floor expanded and "squeezed out" whatever moister was in the bamboo? There are no other signs of moisture anywhere (windows or walls).

The inspection report said that the moisture level was high in a couple of spots and that was were we found the moisture undere the bamboo and the cause of the cupping was "job site conditions".

I am going crazy trying to find where this moisture is coming from.

Sounds like a dewpoint issue. But probably enhanced by the spacers not being taken out, wood had no where to expand. It lifted and a dewpoint caused the moisture to condensate between the wood and adhesive.

Just my guess.

To piggyback on this issue, I have cupping bamboo floors as well in my new construction home. Above grade slab as well. Bought in February 2011 and it's now October 2011 with cupping floors. Is there any alternative to requesting a rip out and re-do of the flooring? (I'm not sure the builder/floor company would re-do it as you never know until the rubber meets the road on the repair, but the home does have a 1 year warranty on it.) Is the sanding alternative worht it?

One would have to know what adhesive was used and moisture tests of the slab...now and prior to install and the wood moisture content prior to install and current, plus the rh and temp in the house. One year is a short time frame, they usually will try and put you off untill the warranty period is up. Better get with it. I'd bet no one tested the slab properly beforehand.

Humidity and dew point.

The concrete has the ability to be below dew point temp, making the adhesive bed below dew point.


Same thing is most likely going to happen to the floating floor, unless you get the humidity in check and keep it in check.