I've got sort of a problem that I'm not really too sure how to deal with. We are installing about 1500 square feet of Kahrs click together floating floor (bought from Ken). We're about half way done and everything is going great except for this one issue. The problem I'm having is that pretty much all the boards are bowed length wise (you lay a plank down on a perfectly flat surface and there is a small gap in the middle). Some are worse than others. This isn't a problem on medium to long runs as the adjacent boards pull everything down tight. But, we've got a small area where the runs are only about 3-4 ft in length and the boards just aren't pulling down tight to the subfloor. So, the flooring moves and is mushy in that section. Initially I thought the problem was a subfloor that wasn't flat, so I pulled everything up in that section and took care of that. It wasn't perfect, but within tolerances. Now, it is perfectly flat. The sealed boxes of wood are stored in the house and the temp/rh are pretty constant. The temp is always between 65-70 and the rh is roughly 40% (give or take 4-5%). All of that is within Kahrs tolerances, so I think the banana effect is just something that came from the factory.

The only things I can think to do at this point are:

1. Just shim up the boards so that there is felt/shingles underneath the bowed section of the boards so they won't move.. That obviously isn't ideal, but I really don't think it would be noticable under foot.

2. As I continue laying flooring in the rest of the house, cull back the planks that don't have (or have less) of the banana effect than others and then try again later.

Does anybody have any other ideas/advice?

Thanks,
Ryan

Some manufacturers and installers say not to be concerned and that the floor will lay flat in time. Personally, I don't risk it. If a floor is not fitting or laying right, I return it for new product. As a professional, I cannot afford to be redoing floors, especially when it is a manufacturing OR storage flaw. But the manufacturer states once you lay it, you own it. If it don't fit, I don't force it. I return it. Just my 2 cents.

Ryan:

With large areas the overall weight of the floor itself will lose the banana board effect. In smaller areas I've resorted to staggering. Anotherwords if it's a four feet wide area, don't use lengths that are all four feet long.

How long were these boards taken out of the plastic?

Thanks for all the responses.

Floorguy, I have pretty much just been opening the cartons as I go. So, the boards would have only been out of the plastic for a few minutes. I don't really remember, but it is certainly possible that it sat open for 24 hours if I finished for the evening and had a few boards left over. My experience so far has been that pretty much all of the boards have this banana effect straight out of the package (some not too bad, others quite noticeable), but that the medium to long runs, as Ken mentions, takes care of the problem.

Ken, I've been following the Kahrs instructions that say to have an end joint in every run (even for short runs) and the end joints spaced at least 20 inches apart. But in this small area they still aren't laying right. Unfortunately, it is in a very high traffic area.

Ryan

I really don't like a real wood click together floor but thats besides the point i can't believe you can't find 4 or 5 good boards to use there i even pull up out of another room if i had to try to fix the problem before i started talking about it or thinking about to much sometimes it takes a little more then wed like to do a nice job besides it real wood ain't that the beauty of it GOOD LUCK WITH YOUR FLOORS

Thanks for everybody's help. I guess what I'm going to do is just continue with my install and cull back the especially flat boards I find for use in this small area.

We love the floor, and have had nothing but positive comments so far. This has really been our only issue so far (other than learning how to get the floor flat, which is another issue altogether).

Thanks for your help.

I'm bringing up this old post because I'm at my wits end with this problem. To rehash, we have a Kahrs floating install (bought wood from Ken) and love it! The only problem is that we have a few places in our home where the layout dictates a short run of flooring (3-4 feet). The areas are about 4 x 4 (so around 16 square feet). For the life of me I can't get the wood to lay down in those areas. I've probably got 30 hours working on just one of the spots. The subfloor is flat, and the problem appears to be that every one of the Kahrs boards has a banana effect lengthwise. If you place a full board on the floor there will be a gap of 1/4 to 1/2 inch in the middle. On a normal run of flooring, the connection with the rest of the floor holds everything down. But with the short run the floor won't lie down flat and moves/makes noise when you walk on it. I guess I wouldn't be so concerned, but this is in the most high-traffic area in our home... leading upto the doorway to the kitchen. Not sure if it matters, but there is a transition strip in that doorway.

I've tried a few different things, including trying to shim up the subfloor with shingles/felt to equal the contour of the banana effect, but that was pretty silly. I'm wondering if anyone has any suggestions?

What would be the downside to gluing these small sections to the subfloor? I have quite a lot of adhesive left after having done the stairs. I would think there could be expansion issues, but I don't really know. Since the floor ends at this doorway (with the transition strip) it seems this might be a possible solution. But I wanted to get the pro's opinions.

I'm really at a loss here. We love our floors, with this one major exception.

I don't have an answer yet but I do have a question. That small area at the door, are there butt joints in every short row, or are they single boards that have been cut to length?

To answer Jerry, there are Butt joints in every short row. I spaced them 20 inches apart as per the Khars instructions

It should not happen, have you tried emailing Ken about this.

I have put down quite a bit of Kahrs and never experienced this, maybe someone else has some ideas for you.

You cannot marry a floating floor to a glue down without a transition piece. My instinks tell me you have a low spot in the middle. I won't contradict you, though.

If you have endjoints in every other row, it is impossible for the floor to crown. That is not a Kahrs thing, it is a physics thing.

Have you called Kahrs?