Sounds like your at wits end trying to deal with this. I know i would be!

Your humidty issue is a good point to start.

But i have this feeling there might be a dufferent issue.
Have you looked into hiring a certified floor inspector?

He(or she) could tell you if its an issue with the wood. Or a install problem or an environmental issue.

I have had a company come out, actually last year and they didnt have a strong feeling one way or another. The fella said that the flooring moisture level was fine and that it might all fix itself over time.
Having looked into this for several years now it seems to me that there are as many opinions as there are flooring companies.
I have talked with members of the National Wood Flooring Association, posted pictures and descriptions and opinons run the gamut.
From everything I have learned it is an odd situation that a dry house/room/floor would result in a cupped board, typically the board shrinks and there are spaces between the boards, but not in my house, when its dry the baords cup.

I'm making a concerted effort to significantly raise the relative humidity in my home to see if it helps...wish me luck.

If I knew it wouldnt lead to divorce I swear I'd rip up all the wood and stain and seal the concrete and be done.

I would agree that your winter humidity is far too low. That would make the top half of the wood dry and shrink...relative to the underside of the boards.

As for what's underneath (plastic, ply), I wonder if there's a source of moisture that's keeping the ply and underside of the boards a bit more moist (therefore, more swelled with the moisture).

Anyway, humidification is likely to be good not only for the floor but for your wellness and comfort. 23% is too dry. Even 30% would be too dry.

Here's some info that might be helpful.

Here is a link that might be useful: Flooring info

I agree that the winter home environmen is what is causing the seasonal movement (cupping).

I agree that the winter home environmen is what is causing the seasonal movement (cupping).

I agree that the winter home environmen is what is causing the seasonal movement (cupping).

See figure 3-3 especially.

Movement even depend son the original location of the wood in the tree.

Wood moves with moisture content.

Nothing can stop it, no finish can seal it 100%.

Flat sawn wood is especially prone to cupping.
Quarter sawn wood less so, but it is more expensive since less usable wood is produced from the tree as it is cut up an it takes more work to maximize quarter sawn during milling.

Here is a link that might be useful: Wood Handbook, Chapter 3

brickeyee,

Thanks for the reference material, quite thorough.
What would have been handy to know on the front end from the contractor was the moisture content of the wood.
When he laid the floor he left gaps in the flooring every 6 feet or so and said that they would swell shut. After about a week of acclimation he returned and was puzzled that there had been no movement.
I think that means that there was more moisture in the wood relative to my home/concrete slab than he had anticipated. If he thought the wood would swell and it did not the only conclusion I can come to is that the wood was, for lack of a better term, wetter than he thought it was, consequently when my home loses moisture the wood begins to move, maybe more than it otherwise would if it had been drier. I recall that he said he had a hard time finding the wood he needed, so goodness only knows where he found it and what shape it was in.
I think a constant RH in my home of about 40% should solve a lot of my problems.
I will continue to study the reference material you've provided to try to get the best understanding I can, and again, thanks for the info and post.

Hmm, I guess I wasn't helpful. My apologies.

I whole heartily agree 23% is at least 1/2 of the humidity one should have in the home. I wouldn't be able to live in that dry of an environment. All wood based flooring products come with instructions for installation as well as the humidity levels that should be maintained for warranty purposes. 55% to 60% is the humidity level for wood products, flooring to furniture. With the AC on (if applicable) in the summer the RH should be maintained around 60%, without it can get as high as 99%. Even at 60% your RH is dropping 37%, of course the floor will cup, no doubt. Even if your vapour barrier above the concrete is not sealed 100% which is tough to do, the main contributor is that huge drop in RH in the building envelope. Control your relative humidity at 55% to 60% and I don't think you will see anymore cupping next winter.

By the way the first thing we do when we open packages of flooring is throw out the warranty instructions for installation, to small to read anyway LOL. All wood flooring products including laminate have different acclimatization procedures. Was the flooring acclimatized if not rectifying the problem may to be to late.

As brickeyee stated the original tree affects acclimatization.

While I'm at it an FYI for all, the softwood products will be affected far more than hardwoods by moisture changes. That it why one will see more hardwood based antique furniture than pines, thus the huge prices some pine antiques demand.

This post was edited by SouthernCanuck on Wed, Jan 9, 13 at 12:14

"While I'm at it an FYI for all, the softwood products will be affected far more than hardwoods by moisture changes. "

Many of the softwoods have a better match between tangential and radial shrinkage.
This means while they still change size, the shapes are more stable.

Softwoods are also often easier to damage, and being considered 'lower quality' items no one really tried to preserve them.

Sorry homebound,

I didnt see that post, the multiple multiple post kinda camouflaged it.
The information you provided mentions drying out the wood and correcting whatever is causing the excessive moisture on the underside of the wood. I dont know where excessive moisture could be coming from. I have over the last four years had plumbers out, foundation people out, even a chimney cap company out to be sure there is no water/moisture intrusion causing this, and I dont think there is, I think that the bottom of the boards have a higher moisture level than the tops of the boards because of the nonstop running of central heat during the extreme cold of the winter. So the bottoms of the boards are relatively more moist than the tops.

I just took delivery of 2 Vornado humidifiers so hopefully I can turn this thing around.

Thanks for posting the link, and please accept my apology for missing it.

SouthernCanuck,

Thanks for the input, wow, if 55% - 60% is the target then yeah its pretty obvious. I had no idea.

Unfortunately after the initial visit from the contractor all I saw were his Hispanic workers which spoke very little English, so there were no instructions given.

Thanks for the wake up call numbers...55% - 60% man what was I thinking!