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

Assuming that your humidifiers are working properly (and it appears so), it's likely that air infiltration is the main cause of your problem (i.e., a loose construction). Being that your property is over 20 years old,your furnace is probably of the low efficiency type (less than 90% AFUE). Does the furnace exhaust through metal flue/chimney? If this is the case, your furnace (and water heater if gas operated and LE) needs to 'pull' in outside (low humidity)in order to maintain a flame. You should also note that as outdoor temps drop, the indoor humidity should be lowered so as not to cause condensation on windows and inside walls (not good). Look around for any obvious leakage areas and try to seal/eliminate. Good luck. V

I'd reckon that you have moist air getting through the ceiling drywall at the can light locations, then that moist air is cooled as it gets into the colder cathedral ceiling bay, condenses, then the condensate is dripping back into the room. Go to the home center or lighting store and ask for "air tight IC cans". Air-tight means the can itself is essentially sealed tight versus the other cans that are full of perforations. Plus it'll usually be gasketed where the can sits against the ceiling drywall. "IC" means the can is rated for direct contact with insulation. Turn off your humidifier. Remove your existing can. Check for water damage/wet insulation in the bay. Let things dry out. If needed you can stuff new insulation in the hole. Add the new IC can, caulk the rim of the can where it meets the drywall. Add the trim kit. Your situation is why I never recommend any penetrations in a cathedral ceiling. Can lights are cathedral ceiling killers in terms of violating the thermal and vapor envelope of the house. Catherdral ceilings are seldom correctly detailed, can lights in them make the matter even worse. Mongo

Photos would be required to offer any suggestions. Are you describing "engineered hardwood" that is layers of REAL WOOD (the surface being 1-6 mm thick)? Or are you describing "laminate" (a word you used in your description)? I would check to see how thick your wear layer is. If it is SOOO thin that you can see the layers of OTHER wood underneath, then it is probably due to the lack of "thickness" on the wear layer. Photos if you can. And let us know if you are talking about engineered hardwood or laminate...you've mixed the wording a little. If you have "high humidity" summers - what are you doing for dehumidifying in summer? Is the AC keeping everything around 45% during the summer? And what level is the humidifier keeping things during the winter? Also 45% of just barely 35%?