Howdy all,
Looking for advice and opinions. My oak floors have been cupped (warped) pretty badly since about 2 months after installation. New construction started Jan 08, moved in June 08 and floor started cupping in late July, early August or so. Called flooring contractor and after looking at the floors they said it’s the moisture from basement that is causing it so it isn’t their problem. Not sure how they determined that just by looking at it for 10 minutes. Wood was brought to house and installed in same day–no acclimation. They said it was kept in climate-controlled warehouse so no need to acclimate.
Main floor of home all 3/4″ oak site finished, 3/4″ ply subfloor over finished and heated walkout basement. Gas forced air furnace in house, radiant in slab to heat basement was fired up in February. Forced air in basement until then. ERV running since house was built, also run dehumidifier in basement in summer out of habit. Humidity in house ranges from 25-40% in winter up to 75% in summer when a/c not running.
How do we know the cause of the cupping? Assuming only real fix is to sand and re-finish (about 1,300 sf), who should bear the cost?
Thanks for your advice.
Replies
I am not a floor professional, but every flooring guy I've worked with has stocked materials on site for at least a week to acclimate. They also use a moisture meter to check subfloor prior to install.
Something seems wrong here.
Coincidentally, there is a similar thread running here now titled 'Engineered Hardwood Flooring'.
Edited 8/18/2009 10:43 am by kenhill3
>>They said it was kept in climate-controlled warehouse so no need to acclimate.
Unless the install conditions in your house were nearly identical to their warehouse then it would HAVE to acclimate.
Did the floor become flat again in the winter of 08-09 (it only cups in the summer)?
forgot to mention the floor flattened out a little bit during the winter heating months but not close to completely. I would say it flattened about halfway back to normal at its best.
When you describe the wood as cupping I assume you mean that each board has a concave surface. Or do they have a convex appearance?
I was thinking pretty much the same thing--as in, "Too bad they weren't installing the floors in the bleeping warehouse!"
It is proper to acclimate to site conditions, but that would not have prevented this problem.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
How wide are your boards?
Is the cupping slight or major?
What flavor is it? Oak Maple Birch Jatoba?
Edited 8/18/2009 5:38 pm by gordsco
I had 3/4"X3 1/4" prefinished wood floors installed in my house in January 2008. My installer was a little worried about the moisture from the crawl space so he went with 15# felt in lieu of the standard flooring paper.
Almost done with the second summer and no cupping and we live in Maryland, a high humidity area.
Runnerguy
how wide are your boards? and it sounds like the humidity is high in the summer when the wood is swelling and then drying out in the winter and the wider the board the worse the cup so sanding it when it is cupped will make it convex in the winter the more even you keep the humidity level the better.
Oak boards are 3 1/2" wide. If the floors went flat in winter that would be one thing but they go halfway.
that is because they went in dryer than your house and never had a chance to aclimate. there is no perfect solution now as I see it. but the wider the board the more noticable the problem such as your case. have you ever noticed in older houses that the flooring is usually narrower like an 1 1/2 and 2 1/4 thats because they did not dry it like we do today so movement was less noticable with narrower boards. not sure what i would do in your case. let us know what you decide and how it turns out so we all may learn. :)
How do you clean your floors?
Anything more than a damp cloth will be enough to make em cup. If you've been using a sponge mop that's too wet, or god forbid a string mop.....it's on you.
Otherwise I'd lean towards moisture in the cellar...
Oak that isn't acclimated doesn't tend to cup, in my experience. It swells, or it shrinks. Cupping is more indicative of one side being exposed to more moisture than the other.
Bing
when oak flooring swells and pushes it has no choice but to cup. no?
"when oak flooring swells and pushes it has no choice but to cup. no?"no, ABSOLUTELY not. If it is swelling from a change in air humidity and swells, the top grows more than the bottom and it crowns instead of cupping.When it swells both from airborne moisture and moisture contained in the subfloor, both sides swell equally and the result is even worse. Boards put so much pressure against each other, I have seen entire floors lift in the center.The only times I ever see cupping is when the crawl is damp and moisture comes up thru and swells the backsides first. This can be compounded by AC in the living space drying the top surface at the same time.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Would doesn't necessarily cup when it swells. It just gets wider and maybe a slight bit longer. In a floor if there is proper expansion space at the walls the floor would just widen out. If there were inadequate expansion space the floor as a whole would bulge, not just the individual boards.
Like someone else said, cupping tends to be due to uneven moisture exposure.
not my experience. It can push an entire section of floor right up off the nails. Boards are still flat but now a whole section is popped up above the subfloor by 1/8 to 1/2 inch.
"Oak that isn't acclimated doesn't tend to cup, in my experience. It swells, or it shrinks. Cupping is more indicative of one side being exposed to more moisture than the other."Absolutely!!!BINGO
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
"Oak that isn't acclimated doesn't tend to cup, in my experience. It swells, or it shrinks. Cupping is more indicative of one side being exposed to more moisture than the other"
-Let's define cupping, then. The floors are expanding with moisture and the tongue and groove joints are pressing upward at the seams, making a wave-like effect in the floor surface. I called it cupping but it is expansion with nowhere to release the swelling so the joints expand upward.
-Also, the 74% humidity is on the main floor on the rare summer days when it gets that humid outside and I leave the doors and windows open. I have never measured the basement humidity.
-I clean the floors with a dry swiffer duster.
-The floors were site-finished, not prefinished.
-I have forced air furnace, and I run A/C when it's really hot, leave windows and screen doors open when it's not.
-The basement is fully finished with a walkout
-There is no indication of what the moisture level was in the flooring or the subfloors when they were installed. All I know is that they brought the floors to the site and installed them the same day, even when I asked them to acclimate them for at least a week. I called them 2 weeks before the scheduled install and asked them when they planned to bring them over for acclimation and never heard back from them until the install.
-so I need to know what caused this --can we if we don't know the humidity of the flooring and subfloor going in? And does it even matter if floors were not acclimated at the job site?
WILL SANDING AND REFINISHING DO THE TRICK? If so, how do I make sure it doesnt happen again? If contractor digs in his heels, I may offer to split the cost of sanding and refinishing after he gives me an estimate.
If this were your new house and the floors cost you in the area of 12k, what would you do?
Thanks to everyone for the input.
When you say that the joint is swelling upward, that sounds like "cupping" to me. This is caused by the face not expanding, beit because of the finish preventing it from soaking in moisture, or because the bottom is growing in width, due to moisture from underneath. It means that if you pulled a piece up and looked at the end, it would look like a "c".
As I said before, I don't think the problem you're having is due to not acclimating the oak. It's wrong not to, but I don't think it's the cause of your problem. If it were swelling past the point of the room it has for expansion, it would stay flat, in terms of single pieces, but you'd get spots where it would hump up, 3,5,10 boards together. If the stuff was too moist when it was installed, you would have shrinkage.
I wish I could give you a simple answer to your question regarding whether sanding and refinishing would solve it. It would be helpful if you knew whether or not they put some kind of paper down at install. As other guys have pointed out, the options would be felt, or red rosin paper. I use photo paper, reccomended to me by some friends in the trade, and have had good luck with it. Reason I ask is that it would seem that if you only dry dust it, then the moisture is coming from below.
First thing I'd do is get a good de-humidifier, draining outside, not into a sump pit. If your basement is finished, make sure dryer vent and bath fans are exhausting outside. See if that makes a visual difference with the oak after a few weeks. If it does, wait it out. the flatter it gets before re-finish, the less material that will have to be removed by sanding. Makes no sense at all, imo, to sand and re-finish without determining the source of the moisture.....
I had one experience with an ice maker hooked up by (thank god) a customers appliance guy. Done on a Friday afternoon, pizzed all over the floor for the weekend, wet enough that the fiberglass batts in the basement underneath the kitchen soaked and fell down, puddles in cellar. Waited a month, my flooring guy hit it with some fine pads, 3 new coats of poly(oil, always) and it looked like new......
As to where to place the blame? If you had huge gaps due to shrinkage, or the floor were humping up in big sections, I'd say crucify the flooring guy.......Unless he meters the oak AT the "climate controlled" warehouse just before delivery, and it's exactly the same as the house humidity, it's just not best practice to put down oak without acclimating it for a good 10 days, minimum. The paper layer in between, I believe, plays a part also. Even then , other factors can come into play, like how long ago plaster was done. Having said all that, 74% seems very high to me.
Sorry for the novella...:)
Bing
" See if that makes a visual difference with the oak after a few weeks"takes more like 2-3 months to come down
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I agree, to flatten out would take longer, but given that it sounds like it's pretty severe, I would bet a few weeks would show a difference.
The example I spoke of was noticeably flatter after 2 weeks, but granted, it had been soaked with water.
I think any further troubleshooting rides somewhat on the % humidity in the cellar.
In reference to the staple vs. nail query, I resisted staples for years and finally agreed to try one out a couple years ago. I have had no troubles at all, squeaks, cupping, or otherwise. These were all floors with either 3/4 Advantech or Fir ply, however. I would not be too jazzed about laying a floor straight over regular t+g osb.....nails OR staples....Doesn't hold fasteners well, imo.
The VB is a good point, and something I've gained an education on recently. Good idea, however, I've never used one,(I will in the future) and I've never had a HW floor go bad on me, in 20 years or so....Probably lucky that I didn't have a real humid basement in the mix, but it still goes back to the % in the cellar question......
Troubling about the GC. As one myself, like it or not, if he hired the sub, he's responsible for EVERYTHING. Otherwise, he's not a gc, he's some kind of consultant, "reccomending" subs, and not worth the typical $ that a gc is collecting to warranty the job. If he's on the edge of bankruptcy...it probly won't matter if you're in the right....can't get blood out of a stone.
Good luck.
Bing
"If he's on the edge of bankruptcy...it probly won't matter if you're in the right....can't get blood out of a stone."YepI ahve mixed feelings on this whole thread, partly because there is no way to know the exact conditions of install because apparently if anybody took moisture and humidity readings, it was the installers only.so any attempt to cast blame on any one is fraught with difficulty.In principle, the GC is the man holding the bag and that is why they make a profit to cover risk and contingencies.But this could also fall into the category of, "It's just one of those things..." with too much unknown and no-one to pin blame on.I'm useually first in line to hang faulty craftsmanship because it hurts all of us when hacks get away with poor workmanship and ignoring basic principles, but I don't see any definite evidence that is what happened here.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
"As to where to place the blame? If you had huge gaps due to shrinkage, or the floor were humping up in big sections, I'd say crucify the flooring guy.......Unless he meters the oak AT the "climate controlled" warehouse just before delivery, and it's exactly the same as the house humidity, it's just not best practice to put down oak without acclimating it for a good 10 days, minimum. The paper layer in between, I believe, plays a part also. Even then , other factors can come into play, like how long ago plaster was done. Having said all that, 74% seems very high to me."
Thanks, Bing. I should say that about 60-70% of the floor is cupped, the rest is pretty flat. But why would that happen 6 weeks after install in new construction? All my vents go outside and I run a dehumidifier to outside drain as well. ERV running as well. Washer and drier in second story above main floor and vented outside. Even the stove top vents outside. The basement is comfortable and has no signs of a moisture problem but I'll measure.
Is it at all possible there is not enough of a gap around the perimeter? Seems like a cheap and easy hthng to check if that's a possible culprit.
I'm strictly an armchair QB/Egr. But I'll share my experience with you. I'll attach a NOFMA article on cupping- they've restricted access to members only on their website.
Before we added on to our house, the only oak floor I'd put down was with a buddy. And he had crawlspace moisture problems that led his new floor to cup. I was determined to avoid that.
When our addition was getting done, we had crawlspace water problems. Poor perimeter drain and waterproofing. These ended up getting somewhat addressed about 6 weeks before the GC wanted to start flooring.
Our contract included acclimating flooring on site for 10-14 days. Of course, GC didn't want to do that. The compromise was a cheap meter from Rockler to compare the wood to the subfloor. But it ended up showing the flooring at 3% and the subfloor at 16% or so. Over the next couple of weeks, with the heat running in the house, this improved but not to within 3-4 points.
The short version is that GC quit, and I didn't get a flooring guy in to put down the material until a couple months later. By then, I'd been running a dehumidifier in the crawl to dry it out (eventually dug up the perimeter and fixed the drain and waterproofing).
The contractor that finished the job ended up a bundle or two short and bought more and put it down the same day. And the last little bit at the end of the room and into a vestibule entry to a bedroom is the only part that swells up with some cupping during the summer.
Two things:
1) Even at site conditions, bundled and strapped flooring is going to take a long time to acclimate. I think you have to spread it out or sticker it to let air get to it and for it to acclimate in a reasonable amount of time.
2) We also had a fridge water leak later that cupped the floor next to it. But it laid back down as it dried out over the next couple months.
I'd check your humidity levels, as others have stated, and look for a potential source below, or at least regulate the basement humidity level. But I'm tempted to agree that the lack of acclimation, and I mean relatively similar moisture levels in the subfloor and oak strips at installation, is the real culprit.
Exemplary tale.
I apreciate it and that link.But as your own experience details, ten days to two weeks of acclimation does not often do the trick. It is just as common to find things in proper equilibrium in three days as it it to find that it takes a month or more.I don't understand why you used the term'compromise' when youy brought in a moisture meter, because that is the end all be all answer, not a compromise.Relying on the old standard "Two weeks on site" is the realy the compromise from standards of good practice of KNOWING what the MC is for both materials.Since you and every one else here have no way of what the MC was at tiome of install, it is hard to understand your conclusion that "But I'm tempted to agree that the lack of acclimation, and I mean relatively similar moisture levels in the subfloor and oak strips at installation, is the real culprit."
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Piffin- the compromise was in buying a $40 meter instead of a more-accurate $100+ meter.
I'm probably jaded, but my read of OPs info was that he was doing mitigation for potential water-underneath-related problems. I didn't see periodically opening the windows and going with natural ventilation as a likely source of enough moisture to cause problems. If the cupping isn't isolated to a specific area with something underneath going on, then I'd suspect that some portion of the flooring hadn't come up enough in moisture level before it was put down.
If there's access to the subfloor from somewhere in the basement, you could always stick it to see what moisture level it's reading now.
basement cieling is fully drywalled, but I would be willing to cut into it for a reading if it comes to that.
mrsludge, thanks for the article and the tale. this article seems consistent with the other one except that it adds the prospect of lack of acclimation as a culprit since the subflooring will have more moisture at installation than the flooring that came from a conditioned warehouse and was installed the same day.
the only issues i have with the author is that he describes such a scenario as being for remodels or additions, yet it describes my sitution accurately which is new construction. He also lays the blame for this on the HO, when in many csaes, such as yours and mine, the contractor insisted on the rush and no tthe HO.
I have decided to do a moisture study of my main floor and basement first then try to determine cause as accurately as I can. That seems to be the consistent message here.
if moisture is high on both levels but similar (within a couple % of each other) then what?!
I think it is entirely possible, based on all the comments and the 2 articles, that if the humidity in basement is not significantly higher than main floor that the subfloor had enough moisture in it to cause cupping in the dryer flooring. But the fact that heating in the winter wouldnt or didnt dry out the subfloor makes me nervous...
"if moisture is high on both levels but similar (within a couple % of each other) then what?!"Something still not quite clicking for you -They should not only be similar, but lower floor have less RH and both have less than 40%! Remember that airborne moisture tends to rise more than fall, so moisturre from the basement will exert more influence on teh flooring that moisture from above all other things being equal. And that since you have a finish on the top of the boards, that slows the migration of moisture in and oput of the lumber on that side.I get the impression that in part, you are as much focused on fixing blame as you are on finding a solution. There have been a great number of times in this thread that when the 2-3 reasons for this are presented, almost alway s with the report that it is nearly always moisture from belowm you tend to ignore that and focus on the one possible reason that might lay the blame on the GC and installer.It is possible that they carried in flooring with a MC of 7% and installed it over a subfloor that had been rained on only two weeks before and had a 20% MC, yes.but once again, NOBODY in this thread has ANY bit of information to lead them to know that aa lack of aclimation was the culprit. Only assumptions. And Again, the most common reason for this problem you have is from moisture in the cellar.That MIGHT possibly be the case, but it is not very likely.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
You're right, Piffin, what was not clicking was that I understood the thread to be telling me that RH from basement is probably higher than RH from main floor, making the bottom of the flooring have more moisture than the top. That's the message I thought I was reading over and over, bottom wetter than top due to higher moisture from below vs. main floor, hence the "what if" of similar RH up and down. Right now I am focused on measuring and tracking RH in the entire house over the next several weeks, doing a moisture check on basement slab, and seeing what I can do to reduce it if warranted.
My focus is fixing the floor, but since the repair may cost money it doesn't make any sense for me to only address the cause on my own and not try to enlist the people I paid to build the house. Call it blame if you want, but I have a feeling that in this situation most reasonable people -even you- would be looking into both things at once, especially if the GC is folding up his tent. Nothing would make me happier than to learn that there is something easy I can do about moisture and get flat floors without getting anyone else involved and without running the a/c or furnace daily for the rest of my life. Now that I am home for the first time in a week I can look into it directly.
Okay, so lets talk about timeframes.
So far, the only theory that I'll entertain, besides a too damp basement, is the theory that the subfloor was too wet and it transferred the moisture into the bottom of the oak.
Did the cupping occur within the first days or week?
Me recollection is that I noticed it the first few weeks, not the first week or day. I suppose it could have been going very slowly from the start but it took a few weeks to hit its peak. It got progressively worse until it was ugly enough to call the flooring contractor and the GC at about week 6 and ask what gives. My frame of mind was denial at first because I paid a lot for the floors and they were brand new so I couldn't understand how they could be cupping, and certainly not so soon.
That's to bad since it would have been easier to diagnose and deal with caught early on
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Can you post some pics of this?I've seen a floor cup from a baseboard nail grazing an icemaker line (one of my guy's nails, too). Made a swimming pool in the crawl space, and the 3" maple floor directly above cupped. Rest of the floors were fine.Stopping the leak, drying the crawl, sanding and refinishing took care of it.The floor in my house is 6" SYP over a sometimes damp crawl. I forget to dump the dehumidifier. The only cups in the floor are where Mrs. 'Snort over watered a Norfolk Island Pine next to a hvac register...arrrrgh. Water got into the cut ends, and cupped a couple of boards center up.Have you gotten any readings in the basement, yet?http://www.tvwsolar.com
We'll have a kid
Or maybe we'll rent one
He's got to be straight
We don't want a bent one
He'll drink his baby brew
From a big brass cup
Someday he may be president
If things loosen up
My meter shows 82% Rh outside (rainy) and 60 degrees, and 51% and 72 degrees inside on main floor (no a/c) and basement shows 53% and 71.8 degrees. A/C hasn't been used in a few days.
The saran wrap is taped to floor and I will check it tonight tomorrow for signs of moisture.
best shot I can get with light coming in windows the way it is. It looks like this on roughly 1/3 o fthe main floor, which is all the same flooring.
Edit: Ack, the photo looks much different on my camera playback, not so large and much better resolution. I'll try again.
Edited 8/23/2009 9:44 am ET by westmich
Edited 8/23/2009 9:45 am ET by westmich
Here's another try. These floors are very photogenic--they look better on camera than in person!
What I now find interesting is that every several feet there is a relatively flat run of 5-6 boards, then they go bumpy again. Wonder if that means anything.
Edit: well, photo looks the same as first, even worse.
Edited 8/23/2009 9:55 am ET by westmich
Definitely see the cupping. I've seen similar in the days when builders used to lay floors during framing Oak would get wet, swell up, and the edges would crush against each other. Made for some pretty good gaps when the hvac was finally turned on.If that cupping happened 2 years ago, and the humidity level stays stable along with no moisture under the saran wrap... sand and refinish... or live with the character<G>If it's humid when you open your windows, your floors will be affected.http://www.tvwsolar.com
We'll have a kid
Or maybe we'll rent one
He's got to be straight
We don't want a bent one
He'll drink his baby brew
From a big brass cup
Someday he may be president
If things loosen up
Do they look something like this???I washed the blue tint off and resized them
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
That's it, nice work. The first one shows a cupped area and the second shows a cupped area blended to a relatively flat area of the floor.
On a guess here - is the flat area over near where it is a walkout and the worse cupping where you have more of a fill basement under it?
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Piffin, I also was trying to see a pattern of more cupping over areas with less air return and more enclosed areas, but that isn't really the case at all.
The interesting thing is that in the home office (about 10x10 room on main floor, contiguous space and flooring with rest of main floor, is the only area with no cupping at all, absolutely none. BTW, do you think that the RH of low 50s in main floor and basement is too high? And would 2% higher RH in basement be a likely suspect for cupping?
"BTW, do you think that the RH of low 50s in main floor and basement is too high? And would 2% higher RH in basement be a likely suspect for cupping?"Did you see earlier in the thread that I'd said that it should be a maximum of 40% and that 15-20% would make your house materials all very happy?
but that people were more comfortable at 40%?
yes 50+ is too high2% diff doesn't sound like much until you consider two things...Tghis is likely indicative that it has continually been that much higher or that it may well have been even more of a difference and is now starting to get to the point of stabilizing.And that with a finish on the top surface to slow that side from absorbing moisture out of the air, and with moisture normally moving UP rather than down, you can see how the bare wood bottoms will absorb more moisture than the finished tops een if they are the sameSo try to get the basement level down to 40% at least. That might mean balance the AC ducting and even get a second de-humidifier for a while
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
sounds to me like he needs to keep his windows closed more.
Sure, but who wants to live in a world where you can't hear the birds sing and have the breeze run through the house? Choosing that or bumpy floors I guess I'll take the bumpy floors and open windows. I just can't believe those are my only choices. We'll see what effect getting basement RH down 10-15 points will have, maybe I can have it both ways. I have lived with wood floors all my life in old houses with really damp basements and no a/c at all and the oak floors have laid flat as pancakes through all 4 Michigan seasons. Go figure.
It didn't look that bumpy. Just ignore it.
There is some that looks bad enough that it would bother me, but I think that if he intends to keep higher humidity levels, he might as well plan to refinish - someday. Looks like it'll need it soon anyway with all the scuffs in that floor
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Maybe I wait another full year and see what reduced moisture does over the seasons. If I have to refinish I'll do it then. I have 2 big dogs and don't mind the nail scratches as much as the bumps--they come with the dogs. And I know I can remediate the scratches without having to worry about moisture levels!I want to thank you and everyone else for your patience and input on this thread. It has been very helpful. I will post progress when there is some worth mentioning. My wife just made a pitcher of ginger peach iced tea--you're all welcome to enjoy some on the screened porch (with the doors to the house and windows closed).
Mmm.... Good stuff that ginger and peach!
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Made with real peaches and real ginger, not the flavored stuff ;-)
Your vet *may* be able to trim the dogs nails shorter by a bit over time.
"We'll see what effect getting basement RH down 10-15 points will have, maybe I can have it both ways.I have lived with wood floors all my life in old houses with really damp basements and no a/c at all and the oak floors have laid flat as pancakes through all 4 Michigan seasons. Go figure."No, you can't have it both ways - there is no way to get the humidity down with leaving the windows open. Houses were an entirely diffeernt animal up until about the mid seventies. Much more technology goes into designing and living in them now. I used to be able to fix almost anything that went wroing on my '57 Chevy PU with just a srewdriver and a couple pairs of pliers too, but those days are long gone
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
BTW, I was on a job with high speed when i flipped those back atcha processed. Here at home on dial-up, I don't even try to look at one that is larger than 200KB
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Where is that dehumidifier?? In line on the hot air distribution or a portable someplace?It is curious you can have up to 74% humidity with a dehumidifier running. Maybe I missed something about that...
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
The flooring company sent the GC and me the attached document from woodfloorsonline.com stating precisely what Piffin said about cupping--moisture from one side higher than the other (i.e. higher coming from basement). The document says NOT to sand when cupped because ends of boards will be thinner than center. It says address humidity levels and wait. I just cannot imagine that with a/c and the dehumidifier running non-stop all summer that we have excess humidity, but I will check it out and remediate if necessary.
SO: what relative humidity levels should I be shooting for on both floors of house (main and finished walk-out basement), in summer and winter?
I need to have a target before I can hit it and see what the floors do. And if the numbers are lower than I get without using a/c, does that mean I have to always have the (*&%$ A/C on to have a flat floor? Man, should have just done radiant and concrete in the whole house!!
Edited 8/20/2009 8:21 pm ET by westmich
It says address humidity levels and wait. I just cannot imagine that with a/c and the dehumidifier running non-stop all summer that we have excess humidity, but I will check it out and remediate if necessary.
74% humidity is not high?
and by the way for those who don't know humidity is moisture
so yes it is a moisture problem
lets see here kiln dried flooring
not acclimated
gets laid same day
finished shortly after
high humidity
wood cups caused by the wood swelling from the underside
and too anyone who thinks cupping is not a form of swelling. why not? the humidity is moisture and moisture make the cells in the wood expand. no?
what does anyone think about sanding off the finish and then leaving it exsposed to the high level of humidity until the two equalize then refinish?
I think sanding the finish to bare wood and letting it catch up will do one of three things.....
It might work
It might flatten and swell so it starts humping in big sections
If the humidity stays at 74% upstairs, it might crown, and he'll have the opposite problem. But only if it's drier down cellar.
Bing
I have repeated a few times that it's not like I have constant humidity in the 70% range--it's a figure I saw on the guage a couple weeks back in the rain with doors and windows open. But I will follow it closely now and document it daily, I am uessing it is in the high 50s to low 60s, though, in the summer.
What should it be?
The differential moisture levels either side of the floor (per your pdf handout) is what I was describing.
Having had an experience with a client whose icemaker leaked on 5"-6"-7"-8" white oak floor and cupped an area I'd have to suggest, after thinking about it, that you consider waiting for now (if you can stand it) - my clients' floor eventually flattened quite a bit.
I would also suggest that you try to keep the indoor RH below 50% if at all possible in the summer (air condition when >50%) and below 25% in the winter. See what happens after a season or two, unless it becomes unusable or begins to show abnormal wear due to the cupping.
Do the moisture test on the basement/crawl slabs as suggested with taped on 6 mil poly 3' x 3' - that will tell you if there is a significant subslab moisture problem.
Jeff
Thanks, Jeff. I will do the moisture test on the slab for sure. RH in the winter 25% is low and makes my throat hurt thinking about it. I usually do about 30% with the aiprilaire, if I recall correctly. Maybe a few degrees higher even.
Edited 8/21/2009 12:44 am ET by westmich
definitely less than 40%
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
"and too anyone who thinks cupping is not a form of swelling. why not? the humidity is moisture and moisture make the cells in the wood expand. no?"Just for sake of arguement, it is easy and common to get cupping by drying one side only, such as with siding and cedar roofing. The cupping is the result of a differential of moisture on tha opposite sides of the wood, not only by the presence of moisture."what does anyone think about sanding off the finish and then leaving it exsposed to the high level of humidity until the two equalize then refinish?"Might work, but not convenient for somebody living there, and once it evens out, the edges could be lower than the centers of boards. Best to wait as long as possible before sanding
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
An exact humidity target is hard to pinpoint.a house and it's components is going to be pretty happy at about 10-15%RH and people feel more comfortable at closer to 40%RH.Keep in mind that another thing that effects that and makes it a sort of moving target is that you are dealing the RELATIVE amt of moisture in the AIR, and not the EXACT amt of moisture in the wood. How much actual moisture the air is capable of holding depends on the temperature.But your goal is to keep the basement a bit drier than the main floor for a couple of months and hope for the best.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
You have cupping. Crowning is when the center of each board rises because the top surface is expanding more than the bottom surface."I have never measured the basement humidity."
You can't argue with them untill you have a history of comarative readings. Basements are inherently damper and more humid than upper floors. Simple fact of life. To disprove it in your case, you need evidence.The concept of aclimating flooring for a certain period of time means absolutely nothing. What the goal is, is to assure myself that both the flooring and the subflooring are relatively close to the same moisture reading. If I deleiver and install the same day, it is because the moisture meter tells me it is OK.
And if I wait three weeks of "Acclimitization" or whatever that is and the readings are still a wide differential, I will still wait. It is NOT the time on site that makes the diff, it is whether it is effective time or not.Hot air furnace and AC both have the effect of shrinking the top surface, so you could have a combined efffect of rising damp expanding the bottoms and dry shrinking top from the dry air.Refinishing will probably fix it for you after three years. Most new houses have extra moisture during that time period and tend to 'settle in'. if the house has not been thru at least two full seasonal cycles in it's current state, I would not refinish yet.Two specific local instances I know of and watch have this problem. Both had the flooring installed after proper acclimation to constant equivalent moisture readings. Both had damp under. One has been refinished after 3-4 years and no more problem. It was pretty bad, because the borads were 5" wide and had enough cupping to trip folkks occasionally.
The other has 3" face boards and a damp crawl under it. I laid this floor myself over 15# tarpaper. The cupping is very slight now. I installed a de-humidifier in the crawl to deal with the humidity and the floors were fine for three years.
Then they deccided to save money on electricity and turned it off. ( actually, I think it was a renter who did that) and the following spring showed pretty bad cupping, but resumption of the use of appliance helped over time, and the upping is more cosmetic - barely felt underfoot, but you can see it when looking across the grain in the right light.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
While sanding and refinishing may do it, the things that would have helped you the most are:- use of 2 1/4" wide flooring (wider cups more - and above a certain width oak is often face-screwed and plugged)
- use of white oak over red oak (assuming that's the case)
- use of quarter/rift rather than plain sliced (assuming that's the case)
- use of Fortifiber HWD 15 or similar laminated kraft/asphalt semi-permeable underlayment (if not used)
- a week or more of acclimatization
Any reputable flooring contractor would be taking moisture readings both at the finish flooring and subfloor.
Did he nail, by the way, or use staples?
Jeff
thanks for the reply, Jeff.
Did he nail, by the way, or use staples? I don't know. Why do you ask?
IF he used staples and IF the underlayment was OSB and IF he used the minimal amt of staples, then that could be letting the edges roll up easier. I am supposing that is why he asked, because staples do not hold as well as nails in OSB, but that problem has some different symptoms than you are reporting, squeaks when you walk on it for instance.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Piffin,
No squeeks, except for one place in pantry so I never cared to mention it to him. Dehumidifier just a portable thing. Not sure about vapor barrier under slab. It has 2" of rigid foam insulation (pink board) but I do not thing there is any vapor barrier.
IF it in fact does NOT have avapor barrier, what can be done about the moisture at this stage?
Also, the 74% humidity I mentioned was from from a single glance on a day when it was rainy and all windows and doors were open for a breeze all day. It was basically a few points lower than the outdoor humidity. We have a large porch that allows us to have double doors open.
Thanks.
OK, the pink foam board would qualify in a limited way as a VB under slab, depending how well it was done.So where are you using the dehumidifier? on the main floor of in the basement?The GC definitely should have a hand in this, bankrupt or not. if you have to file a claim against him in small claims court, do it before his bankruptcy is done.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Piffin,
I use the d/h in the basement directly into a drain. I do it just because I always have done so in a basement.
pcs of oak flooring have to be destroyed to get them out, split out, when stapled, hold alot harder than i ever gave itWoods favorite carpenter
Some installers have gone over to stapling, thinking it holds better. You can tell from underneath which it is. It would be interesting to know the type of fastener and the fastening schedule (spacing).
Underlayment type? Red rosin? Kraft? Something better?
Here's a good article on cupping: http://www.hardwoodflooringtalk.com/discussion-problems/cupped-floors.htm among other problems.
My point on underlayment here is made in the sense that (assuming that the flooring was very dry when it was installed, yet the subfloor was damp) moisture can migrate out of the subfloor into the backside of the finish flooring, causing an inequal moisture exposure to either side - this alone can cause cupping.
So for example, a building has only recently been 'dried in' and the subfloor moisture content measures (Delmhorst meter or similar) at 17-18% while the nicely-dry oak flooring measures at 7%. Do you see how the marriage of these two materials, without a limited-vapor-permeable underlayment, like the Fortifiber, could cause serious problems as the underside of the oak attempts to reach 15% MC + while the nicely dry top (sealed in at 7% MC via floor finish) tries to *stay* at 7%?
Jeff
Edited 8/20/2009 8:02 am ET by Jeff_Clarke
"Some installers have gone over to stapling, thinking it holds better. You can tell from underneath which it is. It would be interesting to know the type of fastener and the fastening schedule (spacing)."
Underlayment type? Red rosin? Kraft? Something better?
-Not sure. Will the answers have an impact on what effect sanding and refinishing will have over time?
Jeff
I think you have about covered it. In addition, what do you think about not using paper at all and glueing with Bostick's Best - flexible adhesive.? We apply it with a notched trowel over the entire surface.
We have had the same issue on a number of occasions as westmich and it always seems to be from uncontrolled moisture swings for one reason or another. A particularly bad one was a floor placed on sleepers over a slab.We had 6 mil poly under the sleepers.It was a difficult site with ledge rock in the rear sloping towards the back of the house. Even with drastic drainage measures outside, the slab got moist after several days of rain.
We sanded and refinished twice over a period of 1 1/2 years and finally replaced the floor completely using the glue method i mentioned earlier. No problems since then.
sorry guys, i'm new to this. Should have read all the way to the end before posting a comment. I'm totally out of sync with your conversation.
What is everyone's experience with the glue down method?
Haven't seen a glue-down - it would not be possible with Fortifiber, right?
not familiar with Fortifiber. I assume it's a membrane of some sort ? Allows some movement laterally between oak & subfloor while reducing vapor permeability?
The glue down method precludes any paper at all between oak and subfloor. Clearly the glue down is a compromise, but it seems to work. In fact, most of my floor subs strongly recommend using glue down method on anything over a 3 1/2 inch board. We are here in the northeast so not sure if this is just a method peculiar to my area?
Fortifiber HWD 15 - http://www.fortifiber.com/hwd-15.html
View Image
thanks Jeff, looks like great stuff. I will ask my subs if they are familiar with it.
Why would you not ask for the contractor's purchase ticket - when did he/she buy the flooring used in your house - and ask to see the acclamation place - the flooring arrived on such and such a date and he/she acclimated them for 10 days - 4 weeks??? in the acclamation building and then installed in your house on such and such a date -- something just does not add up on what is being stated.
3.5 inch flooring just does not cup like this if it is treated as it should -- a flooring contractor of all people knows this -- too much is missing
Sounded to me like the flooring company is large enough that they have their own climate controlled warehouse from which they send out installers. There would be no tickets trail in that case.But I agree there is way too much info missing
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I agree -- way, way too much missing - guy has a climate controlled place, removes, and installs the same day -- either its is not true (climate controlled place or the flooring was removed way too soon) or something went wrong at the house -- 7% flooring just does not behave this way
This might sound like a strange question, but what if the concrete in the basement is too thin--could this contribute to excess moisture in the basement?
I saw through 2 holes in the slab right after moving in that the pink foam board was about 1" below the surface instead of 4" (nominal 4", I get that). I don't know that the 2" of foam was taken into account and they may have poured 2" instead of 4".
I know the foam was not taped at the seams, because I did it myself. I don't think there was any other VB put on because I wasn't there for the pour and it wasn't visible through the holes I saw the pink through.
Edited 8/20/2009 7:33 pm ET by westmich
Interesting goof up there!Moisture will wick up and migrate thru crete whether 2" or 12", but having less than 3" is definitely a poor pour.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
>> Why would you not ask for the contractor's purchase ticket - <<
If a customer asked me to look at an invoice from when I purchased something, I'd politely tell them to F-off.
Also, you need to read the rest of the thread re the acclimation thing.
like I said, what has been stated does not add up - I've handled wood all my life - if I got a response like you just gave -- i would think I am onto something - why would your be so defensive if you have nothing but craftsmanship to be proud of?
Do you share your invoices for the materials, services, etc you purchase with your customers? Most companies do - right?
"Occupation
Government/Public Service Military"Sounds like that is out of his hands.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Yea, I saw that. Sounds though like he is pretty familiar with how to run a building and/or remodeling business.... ;-)
"that is because they went in dryer than your house "You can't say that without knowing all the facts, like...Does he run AC?is the winter heat furnace hot air?how dry was it going in?how wet is the crawl space?Was this prefinished?
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
read more closely. I disagree with you based on facts from the op.
From:
westmich <!----><!---->
11:51 am
To:
Bing187 <!----><!---->
(21 of 22)
123495.21 in reply to 123495.12
"Oak that isn't acclimated doesn't tend to cup, in my experience. It swells, or it shrinks. Cupping is more indicative of one side being exposed to more moisture than the other"
-Let's define cupping, then. The floors are expanding with moisture and the tongue and groove joints are pressing upward at the seams, making a wave-like effect in the floor surface. I called it cupping but it is expansion with nowhere to release the swelling so the joints expand upward.
-Also, the 74% humidity is on the main floor on the rare summer days when it gets that humid outside and I leave the doors and windows open. I have never measured the basement humidity.
-I clean the floors with a dry swiffer duster.
-The floors were site-finished, not prefinished.
-I have forced air furnace, and I run A/C when it's really hot, leave windows and screen doors open when it's not.
-The basement is fully finished with a walkout
-There is no indication of what the moisture level was in the flooring or the subfloors when they were installed. All I know is that they brought the floors to the site and installed them the same day, even when I asked them to acclimate them for at least a week. I called them 2 weeks before the scheduled install and asked them when they planned to bring them over for acclimation and never heard back from them until the install.
-so I need to know what caused this --can we if we don't know the humidity of the flooring and subfloor going in? And does it even matter if floors were not acclimated at the job site?
WILL SANDING AND REFINISHING DO THE TRICK? If so, how do I make sure it doesnt happen again? If contractor digs in his heels, I may offer to split the cost of sanding and refinishing after he gives me an estimate.
If this were your new house and the floors cost you in the area of 12k, what would you do?
Thanks to everyone for the input.
Mike, those facts were mnot in evidence at the time we had an earlier exchance of information and opinion. The quote you offered was actually his answers to all the questions I asked as examples of what you did not yet know at that time
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
so my question is this. During new construction we do not have heat or A/C until after a building final. Were I live, no finished house means no power. So how do you suppose you are going to acclimatize wood into a new construction home. Its not going to happen. If it was winter and you ran portable heat, it would probably be too dry. If it was the summer, like we have in NC it is going to be hot and humid all the time. You would want the wood from a dry cool storage place. It seems that with new construction especially here in NC it is tough to acclimatize on site if not impossible. Probably best tackled with a conditioned crawl in order to minimize the difference between the topside and bottom of the wood, but acclimatizing on site is not going to happen at least in my neck of the woods unless its a remodel of course with a functioning HVAC system
Sounds like our expierences are somewhat similar...
BTW - I'm in Raleigh... How about you? I see you are pretty new here... Welcome!
In North Carolina the standard practice has been to deliver and install on the same day as the construction sites are always more humid that a finished house. I've never had a problem with this practice here. (but you do need to allow a 1/2" gap all around to allow the wood to expand after installation)------------------
"You cannot work hard enough to make up for a sloppy estimate."
i has a querry or two,
1. was the appropriate spacing left at the walls?2. why is a pro not acclimating floors?3. why am i asking piffin? lol Woods favorite carpenter
"they said it's the moisture from basement that is causing it so it isn't their problem. Not sure how they determined that just by looking at it for 10 minutes."
Because it is cupping! I can tell from here from your first lines. Every case of cupping I have seen was from excess moisture below coming up and making the backs of the flooring expand faster than the faces.
describe more about what your cellar situation is and get advice how to do right and prevent recurrance.
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
Bing & Piffin got it dead on. Cupping is to to excess moisture on the crowned side of the wood. There is moisture coming from the underside somehow causing uneven cell size in one side of the wood.
I don't know how the installers laid the flooring but one thing they did do wrong was not to allow it to acclimate. Also there should be a good barrier like felt paper under the flooring. I know that there is a debate about using 15w felt for flooring but I do and I have never had a problem. The common paper is the red rosin paper.
Solutions? There are a couple.
You could have all the flooring ripped up and reinstalled, this time by a company who acclimates the flooring first. This is a painstaking process but I would consider it. Find out if the floor company has a warranty for their product, and then you will have to find out if it has been installed right.
Secondly you could wait another year and see if the cupping is worse, better or the same. If it's a little better (not so cupped) then I would go ahead and sand and refinish. Over the years wood will have a way of evening itself out, but that's years. Maybe consider a penetrating finish like an oil because a top finish like polyurethane will crack & eventually peel if the movement of wood is too much.
Because the company did not acclimate their product (that's like "Floor Installing 101"), and who knows what else they did not do right, I would say you have a strong case to hit them up for the cost of refinishing. They MUST have some sort of warranty. It's up to you but you may have a case to take them to small claims court on this. Before you do that though, you should reconsider if it's worth it. Small claims can have real deleterious effects down the road depending on the situation. Also, your time (and it takes time) is worth money. If anything you can file a claim with the Better Business Bureau through Consumer Protection.
What is the width of these floor boards and what is the grading?
I find it odd and interesting that you say Piffin and Bing got it right, then go on to say that it is the installer's fault.
Without more information, I'm tending to think this is a site problem, not an installation technique problem. Moisture tests, above and below, would be a good thing. 74% humidity in the basement doesn't sound like a good thing. I'd hate to blurt that number out in a lawsuit.
Lets assume that the lumber was too wet and full of moisture. What would happen? My guess is that there would be gaps when it dried out.
Lets assume that the lumber was too dry. What would happen when it was installed? Cupping? I doubt it. It might buckle as it expanded and ran out of expansion space. That would have happened in the first week/month.
"I find it odd and interesting that you say Piffin and Bing got it right, then go on to say that it is the installer's fault. "Not really sure what's confusing you but it doesn't matter. Bing & Piffin are merely pointing out what happens to wood & moisture and also what were the possible conditions.
I'm merely pointing out the possible fact that the floor installers did not take into consideration the existing conditions and factors that would lead to the wood doing what it is doing now and they did not take the proper steps to alleviate these problems.Jeff Clark I believe has listed the problems and solutions in just a few sentences like he usually does.There's a lot more to the craft of laying wood floors than just nailing down boards.
Moisture causes floors to cup.
Once they cup, they never go back to completely flat. Unless you resand them and refinish.
My flooring company does not allow their hardwood to acclimate on site before they install. Not saying it is the best practice, but they guarantee the product - and really that is the reason we have stayed with them for years and years - their service before and after the sale - and their prices are good. I think part of the reason they don't acclimate is because of the possibility theft. I know their guys are strictly forbidden from leaving any materials on site over night. Here (and I would think elsewhere) if a sub supplies materials and they are stolen before they are installed it is on the sub. Once materials are installed it is on the GC.
If you want to do some investigation get a moisture meter and check the subfloor from underneath.
Is there any moisture problem in the basement? Or is it bone dry? Did they put poly plastic down before they placed the basement concrete slab? If the concrete floor is dry, take a piece of poly plastic about 3'x3' and tape it to the concrete. Check a week later and tell us if moisture droplets have formed on the bottom of the plastic.
What does the GC say?
Thanks Matt. GC said it's between me and flooring guy, which is a cop out since he hired the floors done and not me.
Moisture in basement will be measured when I get back home for sure.
That is definitely a cop-out since he Was the guy responsible for seeing that things were done right to begin with - such as making sure there was a VB under the basement slab, a large source of basement moisture rising in most homes. If he neglected that, he is right in the line of fire.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
>> GC said it's between me and flooring guy, which is a cop out since he hired the floors done and not me. <<
Every product that is installed in the houses that we build is marked up, or it just falls under the amount that we marked up the entire project. This markup is to cover overhead, profit, WARRANTY WORK, etc.
No GC wants to have major problems with a home he builds because major problems = major $$, but they have to step up when something does go wrong.
I'm not saying that this is solely the GC's problem, but what I am saying is that he needs to be involved in the solution. Like you said - it is HIS sub - not YOURS. He could say it is because you don't use your AC but heck HW floors have been used in homes well before AC was commonly used. 74% indoor humidity is very high though. I just looked at ours and it is 57% indoor and 90% outdoor right now. We have 3" white oak #1 select (it looks to me) on a large part of our house. It is fine. We also have a conditioned crawl so it is a safe bet that the CS humidity is the same.
Let me ask another Q that I don't think has been covered: Exactly how much is the floor cupped?? I know you said 60% of it or something, but how much are the individual boards cupped? Lay a steel straight edge on it or similar. Measure it with a feeler gauge, ruler, or whatever you have. Take a pic as the light reflects off of it and post it. Can you clearly see it when entering a room? Or do you need to get down on your hands and knees? Can you feel it when walking on it in your sox or more when you run your hand or foot across it in a sweeping motion?
Re the acclimation thing, I'm wondering if we may be roughly split between remodelers who are installing in conditioned space and new construction guys? There are some arm chair quarter backs posting here too.
Exactly how much is the floor cupped??
-I will measure it when I get home. It is visible to the eye in any light and in the right light accross the grain it looks like Lake Michigan on a windy day. No breaks in the tongue/groove seams and I don't trip over it. It's just butt ugly.
My builder is nearly or totally bankrupt, unfortunately. I withheld a couple grand from final payment because a few things still were not finished at close. That was a year ago, and the flooring issue is just now getting addressed by him. I may be able to use that money to get the floors redone, but I will only do that if it will be a true remedy based on the other conditions discussed here.
"Re the acclimation thing..."Thank you for using a term that means something instead of the made up word with lots more letters in it that has been flying around here
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
"Thank you for using a term that means something instead of the made up word with lots more letters in it that has been flying around here"LOL....You been on that island a little too long my friend.
Is your helpers name 'Friday' by any chance?
New user name: Piffinson Crusoe ! ;o)
Love it!
Hardwood floors cup for one reason only; the boards are wetter on the bottom than they are on the top.
A lot of things can contribute to this, but basements are the number one cause. The humidity is naturally higher in the basement than in the conditioned space above.
You can contact NWFA, the National Wood Flooring Assoc. and request an inspection by a trained wood floor inspector in your area.
But...cupping is always a site problem....gaps or buckling are installation issues related to acclimation.
There are a couple of points that have come up in the responses so far that I think should be clarified.
Whether they allowed the flooring to acclimatize or not is irrelevant. Wood stored in a house for weeks will simply adjust to the ambient humidity at the time it is installed - which may or may not be the humidity that your house maintains after you occupy it.
There is a correct moisture content for flooring which is dependant on your location and climate, and there are readily available charts that will tell you what it is. The correct level is generally determined by the mid-point between the extremes in humidity your house moves though annually, and it is important that you minimize the swings as much as possible.
If the flooring arrived at your site from the warehouse at the correct moisture content why acclimatize? If it didn't or their warehouse is at the wrong moisture level then that may be where the problem started
Edit: I somehow missed reading Piffin's last few posts. I think his analysis of what is occurring rings true.
Edited 8/22/2009 11:06 pm ET by fingersandtoes