Our house is three years old. Lsst air conditioning season and this season our hardwood floors have warpped. Each board has turned up on both edges of the board. Our contractor said that there was a water problem under the house. We looked under the house and found no standing water. We then contacted a moisture expert who tested for moisture content under the house; only to find that the moisture content was within normal limits. We have purchased a de-humiditifer which has been running/collecting about a 1/2 gallon of water in a 24 hour period. The floors have not gone down. Last year as soon as we turned off the air conditioning and turned on the heat the floor boards when flat. Does anyone have any suggestions as to what is causing this problem.

Are these "real" 3/4 inch solid hardwood floors?

Is the floor installed over a concrete slab or over a wooden subfloor with a crawlspace or basement beneath?

Where do you live? (State or Province)

The problem is realted to moisture level in the air, and the fact that the floors warp during cooling season may indicate that your interior is is too dry or that your dry interior air is pulling in moisture from the slab or basement...

Please give more details to the questions posed above.

We live in coastal North Carolina. We have had the moisture content in the subfloor tested and it's 11-15%. There is not any water standing under the house. Since my last post the water collected in the de-humidifier (inside the house) has decreased to about a quart a day.

Are these "real" 3/4 inch solid hardwood floors? -- Yes

Is the floor installed over a concrete slab or over a wooden subfloor with a crawlspace - the floor is over a wooden subfloor.

Sounds like the problem may be that the floors are too dry as a result of the dehumidifying effect of running the AC in summer.

You may actually need to humidfy the house.

Optimal humidity range is in the 30% range for wood floors. Sounds like they are drying out.

Remember cooler air is dryer air, which is why air feels dryer in winter.

Optimal indoor humidities in winter are no less than 30% otherwise your nose and throats feels excessivley dry.

I have the same problem except they were laid over a cement floor. What would be my problem?
Thanks

I hope someone has an answer about the warped wood flooring. Ours was laid last year after Hurricane Charley and has since had warping in several areas. The flooring was glued down to a concrete subfloor. How do you repair the flooring? It is solid oak tongue and groove Bruce flooring.

This message has been edited. Last edited by: Marion,

I would be interested in this problem also as I am about to install a 3/4" Oak floor. I am wondering about vapor barrier. I have been told that it is no longer necessary or standard practice to use felt paper or rosin paper under hardwood flooring, although I can't find ANY manufacturers yet that say this is the case.... all still highly recommend it as standard practice. I thought about not using it, but stories like this make me wonder if theirs is a job that the paper was left off as "not needed". Anyway... I paid the $40 for paper tonight, just to be old fashioned I guess, but I still think it serves a purpose.

We had 3/4 inch solid hd wd installed over concret floor and had them place 1/4 inch plywood and then felt paper. I still have some warping. Any answers?

After reading about the significants changes in relative humidity inside these homes, I am not suprised with the outcome. At this juncture, I would look for ways to stablize or reduce these big shifts in moisture. The first thing to do is purchase a hygrometer station with a couple monitoring units. Situate these in various rooms of the home and measure the changes between seasons. After recording several seasons' records, contact a mechnical contractor and ask if your situation is normal and/or if you can abate the shifts somewhat -- at least take the extreme highs and lows off your humidity swings.

Once you do this, your wood floor with stabize and look the same year 'round. If not, just live with it and consider it a lesson it hiring the right flooring contractor or general contractor.

Wood flooring (solid or engineered) will move with moisture changes (liquid or vapor). Plywood products (engineered flooring) is somewhat more stable than solid flooring -- but still will move with moisture changes. Wood expands as it picks up moisture (until it reaches it's fiber saturation point) or becomes "balanced" or "acclimated" to it's surroundings" or "environment". Wood contracts as it gives up moisture or until it becomes "balanced" with its environment. Wood will never reach zero moisture content for all practical purposes except under an artificial environment (e.g inside an oven).

Wood moves in all directions as it changes moisture content but primarily tangential to it's growth rings. With standard solid wood flooring this means it will move only very slightly lenghtwise and mostly in the direction of cut. For example a quarter sawn flooring board will want to expand/contract more in thickness than in width while a plain or flat sawn flooring board will want to expand/contract more in width than in thickness. This is why quality wood flooring installers insist on quarter sawn flooring, engineered flooring, extremely stable flooring or a combination of such products be utilized where significant moisture changes are anticipated (like those floors I read about above here). Other similar projects are those that are over in-floor radiant heat or when borders are used surrounding a room of wood floor. Anytime reduced movement in wood flooring from changes in moisture is suggested, look for products that feature these stablizing aspects.

Marions said:

quote:

I hope someone has an answer about the warped wood flooring. Ours was laid last year after Hurricane Charley and has since had warping in several areas. The flooring was glued down to a concrete subfloor. How do you repair the flooring? It is solid oak tongue and groove Bruce flooring.

The problem is likely the glue and the concrete.

Most of Bruce's solid hardwood products are not intended to be glued and Bruce does not recommend installing their floors over concrete at all. See what type product you have and check the installation guildelines:

http://www.bruce.com/resflram/na/bruce/en/us/article17862.html

Jena likely has the same problem.

Roger G said:

quote:

I would be interested in this problem also as I am about to install a 3/4" Oak floor. I am wondering about vapor barrier. I have been told that it is no longer necessary or standard practice to use felt paper or rosin paper under hardwood flooring, although I can't find ANY manufacturers yet that say this is the case.... all still highly recommend it as standard practice. I thought about not using it, but stories like this make me wonder if theirs is a job that the paper was left off as "not needed". Anyway... I paid the $40 for paper tonight, just to be old fashioned I guess, but I still think it serves a purpose.

Many subfloors themselves actually act as approved 'vapor barriers' because their glues give them a perm rating of less than 1.

For this reason it is not necessary to have a 'vapor retarder' over many structural sheathing subfloors.

The recommended rosin or tar papers are not necessarily for 'vapor protection', but rather to provide a layer between the wood subfloor and hardwoods to eliminate squeaks.

I have installed hardwoods over very wet and damp crawslpaces without vapor retarders under then hardwood and have experienced no ill effects.

As long as the moisture dynamic is down into the crawlspace from the house and not up into the house, and as long as the craelspace is adequately ventilated, a vapor retarder bewteen subfloor and finished floor is not needed.

Good Comments Swiss Rogue...
Keep 'em coming...

Any wood flooring glued directly to concrete or wood subfloor or underlayment will find itself at the mercy of several additional factors beyond those normally affecting a nailed, stapled, glued/nailed or free floating floor. These additional factors include but are not limited to the following:

1. Quality of the mastic (including both the holding power and it's elastomertic characteristics (it's ability to flex or move after is had dried/cured)

2. Plumbness of the slab, underlayment or subfloor

3. Cleanliness of the slab, underlayment or subfloor (being free from foreign particles, dust, debris, liquids, sealers, etc., that might interfere with the adhesion of the mastic to the slab, underlayment or subfloor)

4. Ambient or existing moisture within the slab, underlayment or subfloor

5. Migrating (or chronic) moisture within or under the slab, underlayment or subfloor

(#4 OR #5) CAN BE THE CULPRIT OR AS USUALLY THE CASE -- ONE OF THE CUPRITS -- BEHIND THE WRAPED WOOD FLOORING IN THE "MARIONS" PROJECT)

There is currently a movement afoot (motivated by slab-on-grade builders/developers and their flooring subs) to develop a trowelable elastomertic barrier for use as a primer or sealer on concrete slabs prior to directly gluing even solid wood flooring to them.

It is claimed (in some circles) that such products already exist. In fact, there are a number of wood flooring contractors I'm acquainted with that are already depending on such science existing within the qualities of a few mastic manufacturer's products. That is to say there are some reputable wood flooring contractors out there who currently install solid 3/4"-thick random length wood flooring directly over trowelled down "barrier" products applied to slab-on-grade subfloors.

I have personally contacted the mastic manufacturers involved and found that they were not specifically guaranteeing all such installation procedures. What I was told by the mastic manufacturers involved is that what they are really stating is that it is "OK" to glue down engineered or solid wood flooring over their "barrier" products utilizing their specific wood flooring mastic.

I think what they're trying to tell me is that they have a "barrier" product that seems to work (in the lab) and conditionally in the field (actual projects). Like so many other new developments in construction products, the manufacturers will leave it to the actual contractors involved to make or break the products -- or take the edge off the lawsuits (if any). In other words they never really know how well a product will work until the "rubber hits the road". They'll find out how well it works -- if it works, where it almost always works and where it doesn't work at all -- basically all the constraints of a new product before they really pour a lot of money (and their reputation) into it.

Most of the really top notch wood flooring contractors I know are still quite leary of all the claims. Still there appears to be some degree of merit to them. A cautioned degree of optimism is called for in my opinion. Personally, I really want these products to work. I just feel cases like the "MARIONS" warped wood floor mentioned here as well as others I'm acquainted suggest we use some measured restraint before barging ahead with some pretty significant claims.

REPAIR:

Going about repairing the MARIONS warped wood floor can be done like any other T & G wood floor. It will be a little more difficult in that after the affected boards have been chiseled or routered out, the subfloor (slab) will need additional cleaning to remove bits of wood and glue. Glue can be a mess to clean up and a really good glue can be a really tough mess to clean up. Often the glue will bring chunks of concrete with it. These divots will need to be filled (with a compound suitable for the slab and the wood). Some installers use an extra glob of mastic for this. That will work if the holes created are not too large. If significant craters are created, you may have to fill the holes with a good concrete leveling compound. I find utilizing more polymer (installers often refer to these polymers as "milk" as they usually have the appearance and consistency of fat free milk) and less water with the concrete leveling/filling mix makes for a much faster drying and tougher more elastomeric end product. Always check with the manufacturer or re-seller of the product you are using to confirm any changes in actual product usage you may want to employ.

If the MARIONS are looking for a "how to" for slotting the new T & G boards into an existing floor there are many articles (with nifty graphics) available on how to do this. I know because I have written a bunch of them for the different wood flooring associations, trade periodicals and consumer magazines. Contact The National Wood Flooring Association (NWFA.ORG) -- one of the associations I was referring to above) to get one of these. The limits of time and space (and graphics) don't allow for me to give a good description of the many ways for doing such repairs in this column.

I hope this has been a help.

Boy it’s going to be hard to follow an act like that....well written Swiss Rogue .

With having a background in wood and furniture building I see the same problem being presented by the above posts - different moisture levels attacking the two different sides of the wood flooring at one time - hence the cupping. If the moisture levels were the same on both sides of the wood at the same time regardless of what those moisture levels were one would only have to deal with expansion and contraction properties.

It is my understanding one of the basic principals of stabilizing wood is to treat each side of the wood as one does the top side (the side that is exposed), regardless of what product is used as a finish. By doing this the wood absorbs and displaces moisture at the same rate evenly on all sides of it’s self, equally - this is paramount for true wood stabilization.

Now in the case of plank flooring if one were to finish all four sides of a plank before installing it and they laid that flooring as described by the manufacture, the planks would still cup, but this time the planks would cup in the negative direction (high center) - it would have to.

It has to because that four sided finished flooring would again have an unbalance. And that unbalance is the two edges/ sides of that plank is tight up against other pieces of wood and the underside of the plank is adjacent to the wooden sub-floor. And because those three sides have a full finish and are adjacent to a solid wooden surface they would not absorb nor dispel moisture at the same rate as the face which only has a finish to control the amount of moisture gain and lose. It is on those principals why a hardwood floor is only finished on the face/ top side. It is the adjacent wood surfaces that control the rate of moisture absorption and displacement much like the finish on the face of the flooring does. This makes for a balance finish for this application and will provide for a stabile product. Well that’s the principal that applies, but when you have a great variance of moisture levels attacking the two opposing sides of wood at the same time that balance goes out the window.

Have you ever bought a good straight length of board from the lumber yard and put it on the grass, driveway or concrete floor and came back in a few hours only to find that wood has gone for a siht. Well that happens because the wood is exposed to a strong variance in moisture levels attacking two different sides at two different rates. Then have you ever tried flipping the board over for an equal length of time to see what happens? Well in most cases you will draw it back in to flat.

So hopefully I have successfully explained why hardwood floor should and should not be used in some applications. IMHO this is why I feel hardwood flooring is more suited to the main floor and upper levels of homes with full basements in northern climates....in these applications we are talking about stable or constant moisture level conditions. So if you are having cupping problems with your hardwood flooring you really need to be looking very closely at the ambient and surface moisture levels on both side of the board. Sorry but in a lot of environments you will not be able to get that wood to lay down and behave. JMHO

Have read these postings with interest. Our house is on a concrete slab in North/Central Maryland, and we want to install hardwood or engineered flooring. We've been told everything from it can't be done to we have to install subflooring AND vapor barriers, to don't bother it will just warp eventually and have to be removed! I have severe allergies and really don't want to recarpet. This advice is from the experts at the largest home improvement stores and the local small flooring businesses. We are so confused at this point! What can anyone suggest as to: the best flooring for wearability (3 dogs in family), ease of installation and how to keep the cost down. Thanks!

Please don't despair doggymom. I like you suffer from allergies. With the kids gone and grandkids visiting, we still make room for a large malamute (nearly 200 pounds) that sleeps on our hardwood floor (on a throw rug) next to our bed on my wife's side. Even though he was my birthday present -- 'cause I love malamutes -- he will always be my wife's best buddy. Up until a few months ago, nearly every room in our home had exposed hardwood floors. Our masterbedroom was the only room left carpeted -- at my wife's request -- when I installed new wood flooring for a book and videos I was doing on the installation procedures of hardwood flooring. After nearly 20 years, our master suite was the only room in our home with odors. My wife couldn't take it anymore. The real kicker was that the house had been built with hardwood flooring in our master suite but had been covered by carpet with the original owners. We had left the carpet in place for "warmth" and "comfort" -- my wife's words. Every time she asked if we could pull the carpet and refinish the wood floors underneath I balked (because of the hassle moving in and out) reminding her of her decision originally. I finally relented -- we all make mistakes -- because of the odors, my allergies, the impossible-to-get-rid-of dog hair, dirt, spills, doggy throw up and other stuff. Plus, I really do love my wife and want her to be happy. So we did it. I am REALLY GLAD WE DID!

Now, for the bad stuff. Our current dog out weighs our last dog by nearly 100 pounds. All dogs can and will scratch hard surface floors -- even metal or stone ones. Get used to it. Our dog however not only scratches, he digs into the surface of the wood leaving large divots or wounds -- up to 1/8" deep in some places. Some of these have caused the finish to lift off leaving a dry dull surface. I should be fixing these spots because as time and water (from damp mopping and foot traffic) attack them they will become nasty hard-to-repair spots. In other words, the next sanding and resurfacing will not remove all the damage done if I allow things to continue. What I should do and what everyone who reads this with similar situations should do AS SOON AS POSSIBLE is seal or coat these areas with a spray top coating (available from hardwood flooring outlets in the finish and sheen currently on the floor). At the very least, coat the spots with a penetrating oil sealer (e.g. linseed oil & white spirits -- this is a nontoxic "green" type of product) to prevent further damage to the wood inself. If an oil like this is used, it will leave a dull looking spot that needs replenishing from time to time but at least you're not doing more damage to the flooring mean while. Such areas should be refinished or recoated at your soonest opportunity. Look at them like a hole or leak in your roof. You should re-roof (that is refinish your floors) but at least patch the hole or leak (spray or coat the damaged spot until it's time to refinish).

Now, as for the best application of wood flooring in your situation, I suggest you speak to a GOOD wood flooring contractor in your area. I know of several but I don't think this column is the right place to name them. Look for an old established company that does only wood flooring. That's usually the best bet. That's the kind of company I have in my region.

An engineered wood floor is always a good bet but I have installed lots of solid wood floors over on or below grade slabs if that's what my clients want. The key is knowing what you're doing. If the installer doesn't, then you will have problems. If you find the right installer, follow all their specifications implicitly. If you are someone else starts putting constraints or limitations on what they can or cannot do, you are guiding yourself toward the rocks in an already leaking boat.

If it were my house, I would deal with the height problems and install a two-tier system plywood underlayment on top of the slab. But first, I would put down one possible two layers of 6-mil poly with overlapped or sealed seams running in opposing directions. These would be my cheap insurance against moisture migration through the slab. The two layers of plywood would also run in opposing directions with all the seams overlapped then glued and screwed to one another but free floating over the poly-covered slab. The finish floor (hardwood) whether prefinished or site finished would be nailed or glued and nailed to the floating plywood underlayment system.

Now this system is not cheap, but it is as close to a foolproof system as can be installed.

If you want cheap. You'll have to take chances. Isn't that the way it always is? Cheap is what I did in my below grade basement. I glued down an inexpensive solid site finished parquet. You could do this with an inexpensive engineered strip, plank or parquet -- site finished like mine or prefinished.

If any moisture comes up through the slab, you'll probably lose your floor. If you choose a savy contractor, he or she will use a good elastomeric waterproof mastic. Such a choice can help loads if you have a leak, flood or moisture migration. Chances are you would probably lose whatever you installed there anyway if you have a major flood -- except for stone -- and there are issues with wet slabs and stone as well that I won't go into here. So, I say, go for it but hire a good technician. They're not cheap but they're not expensive either. Like the old saying -- you get what you pay for.

Good Luck!

Thanks Swiss Rogue! Lots of info to consider. Give a hug to your doggy buddy for us! Dogs rule! (At least at our house they do!)

I installed 400 sq. ft. of 3/4" T&G Hickory flooring in the kitchen and dining areas. It was put over wafer board on trusses. I put down the manufacturer's required plastic barrier and then roofing felt on top of that. The boards were stapled (serrated type) through the tongue areas with a air/hammer hardwood nailer. This was 3 years ago. A month ago we had 12" of rain in 24 hrs and the sump pump ran every 2 minutes for a couple of days, and is located in the basement just below the dining floor. The door to that utility room was closed during this time, so the moisture level was probably high. The hardwood boards lifted along one line in the dining area, probably where a seam is in the wafer board. I have placed 2x4's with cinder blocks on the floor to bring them back down. I am assumming the staples have pulled out. I am considering drilling through the subfloor from below and trying to pull the hickory boards down flat, to stay. Careful measurement will be necessary to avoid going completely throught the hickory. What do you think about this idea? Should I try it before resorting to removing the boards (not damaged) and putting them back down again?

First off, did you check your homeowners insurance? This should be covered/

Once the floor bows it is almost impossible to fix without removal of some boards. Your best bet is to tear it all out. You must also fix the issue with the excessive moisture within the lower area below the kitchen, or its going to happen again.
The wafter sub-floor also has moved. This material is like a sponge that will soak up dampnes quite fast. What has happend all of the boards have swollen and expanded, the weakest part is what popped up. If you look carefully you should see each board with a cup in it. What should be done to fix this if the boards can be re-finished is to remove the two boards and plane them down ever so slightly then face nail them back into place. Refinish the floor once again.

But check with insurance first. You may be able to get a new floor and do it correctly.