Hardwood Floors shrinking

[Ira Boren]

I've got a beautiful cherry Arenberg Parquet pattern floor in Los Angeles. It's about 15 years old. The house was recently remodeled and the oil based finish sanded off. The floor was refinished with a water based product. The finish was chosen because of it's quick dry and cure time. The immediate results were fine, but it's been about 3 months now and the floor has shrunk tremendously. It was previously so tight that you couldn't slip a piece of paper between the boards. Now it's open throughout and in some areas 3/16" wide. It's also apparently not finished shrinking, as it seems to continue it's process. There are no underground water pipes (in the attic). Any suggestions?

[Leo Graywacz]

Time to humidify your home. Look at a minimum of 35% and probably 50%. Wood shrinks when moisture is lost. Taking off the old finish and putting a new one on opened it up to moisture loss.

[Ira Boren]

wouldn't that likely cause uncontrolled expansion or warpage? Also, how and for how long would I do that?

[Leo Graywacz]

It will be very slow. It will be controlled. Unlikely any warpage will occur. You do it as long as it takes for it to come back.

[Ira Boren]

How does one humidify the house and wont it eventually dry back again and cause the shrinkage?
i believe that i caused the problem. near the end of a major remodel, i had the floors sanded, covered with plastic sheeting then paper and taped closed. i thought i was protecting them from the painting that took a couple of months. the floors were slightly cupped in some areas but i had to live with it. chose a WB product and then the damage continued to show it self. its still occurring several months later. we're 1/4 mile from the ocean.

[Leo Graywacz]

Depends on your heating system. If you have a forced air system it's easy. There is an attachment that goes near the plenum. If you have baseboard or cast iron then you need to get humidifiers. Covering the floor with plastic isn't what did it. Taking off the finish is what did it. You allowed the wood to vent off it's moisture in a dry atmosphere. If you get it into a less dry atmosphere it will absorb some of that moisture and grow in size a bit.

[Ira Boren]

Thanks for your advice Leo. I'll contact my HVAC man and inquire about what is needed to attach to the plenum. Being winter now and the heater on quite a bit, the house is even dryer and the shrinking is continuing.

[allen thunem]

have your hvac guy look into honeywell tru steam
best on the market ion my opinion
used one for many years and it is great
a bit pricier than most but well worth the extra cost

[Peter Quinn]

Could be the old double whammy. Wood is at equilibrium, nailed down a long time. You have floors sanded....that opens surface up, but the bottom has
never been finished on these boards, RH has been changing over its life time to no previous ill effect no? Humidity moves through boards constantly, a top coat of finish on a floor will slow this but it's hardly hermetically sealed.

My intuition is it's the Water
Based product at work. Lots of opposing intersections on a parquet, you dump what is essentially gallons of water on it, wood swells up, all the joints look great as they are swollen shut tighter than ever, the whole floor grows a little under the base baseboards. Several heating months later.....dry air, moisture leaves, floors shrink and recede, gaps open up. I'm not convinced any amount of humidity control is going to return an old parquet to perfect, but it's a good environmental control to have anyway.

[John TenEyck]

I agree, no finish stops moisture vapor transfer, it only slows it down. The old finish did not keep the wood artificially higher in moisture content than the RH in the house would allow, such that it suddenly dried out when it was sanded off. I would suspect something else was done in the remodeling project that has lowered the average RH in your house. Did you have a new AC system installed, or something similar?

John

[Mike Heidrick]

Heater? In LA? What, Is it the cold 70? ;)

Was the flooring not dry when put down?

[Stephen Cherry]

My intuition is it's the Water Based product at work. Lots of opposing intersections on a parquet, you dump what is essentially gallons of water on it, wood swells up, all the joints look great as they are swollen shut tighter than ever, the whole floor grows a little under the base baseboards. Several heating months later.....dry air, moisture leaves, floors shrink and recede, gaps open up. I'm not convinced any amount of humidity control is going to return an old parquet to perfect, but it's a good environmental control to have anyway.

I'll vote for this one. The water based product could swell the whole floor and push it out further than the normal summer-winter movement, but the shrinking will not push the edges back in.

Of course, something that was pushed out should be able to be pounded back in, but that might take a lot of work, particularly for a parquet floor. The first thing I would try is the rubber end of a floor nailer hammer, starting from the center of the floor and working out, it may be possible to beat in back in by pounding at an angle.

[Todd Burch]

If you have a hammer, with a wood handle, and it gets wet (say, you soak it in a gallon of WB finish...), the handle will get tighter because the wood swells up to the sides of the hammer head... but it's not done swelling, so it swells some more, and now, because the hammer head ain't going to give (and your walls aren't going to budge either), the wood fibers collapse/compress on themselves. This is no big deal at first - the handle (floor) is tight, tight tight. But, then it dries out. And shrinks. And shrinks. And shrinks. And now, the handle is loose, but it never was before. Since the wood fibers crushed on themselves, their equilibrium state is now smaller than it was before.

That's my explanation. I'm sticking with it.

Todd

[eugene thomas]

Not to hi jack thread but going to have 1400 feet of walnut flooring in new house. Water base finish not the way to go??????

[John TenEyck]

I would have no hesitation using WB finish on a new floor. In fact, it would be my product of choice. It's used all the time. Companies have whole product lines devoted to WB floor finishes. The root of the OP's problem has to be somewhere else.

John

[Leo Graywacz]

If you have a hammer, with a wood handle, and it gets wet (say, you soak it in a gallon of WB finish...), the handle will get tighter because the wood swells up to the sides of the hammer head... but it's not done swelling, so it swells some more, and now, because the hammer head ain't going to give (and your walls aren't going to budge either), the wood fibers collapse/compress on themselves. This is no big deal at first - the handle (floor) is tight, tight tight. But, then it dries out. And shrinks. And shrinks. And shrinks. And now, the handle is loose, but it never was before. Since the wood fibers crushed on themselves, their equilibrium state is now smaller than it was before.

That's my explanation. I'm sticking with it.

Todd

Yet the walls in the house will give. That hammer won't give until the pressure becomes to great and it breaks catastrophically.

[Peter Quinn]

Not to hi jack thread but going to have 1400 feet of walnut flooring in new house. Water base finish not the way to go??????

There are lots of great WB products out there for floor finishing, and I wouldn't hesitate to use a quality brand. It does have a learning curve, so you don't want the guy laying it down to be doing this for the first time on your house. And if that guy is you.....practice a lot first! If hiring a contractor, make sure he has experience with the WB product to be used. For regular lineal footage strip or plank type flooring I don't imagine the WB product will be a problem, good ventilation is a good idea, some air movement, let the water flash off properly, but not too fast so id doesn't level. Three moderate to light coats are better than two soakers for most types of finish, if you apply WB too thin it won't level properly, too thick and it has a blueish plastic hue, just right and its great. Just right takes most guys a few jobs to perfect at least. Only issue with WB on walnut is it adds no warmth, there are ways to overcome that, make sure you do a complete finish schedule test to make sure you approve of the results.

My comments and theory were specific to the OP's parquet situation. If he had said new floor, I'd say the wood was installed too wet or poorly acclimated, if he said slab on grade or even first floor I'd be testing the substrate or basement. But he is having problem with 100yr old parquet on a second floor. I'm not a flooring installer, but I've built plenty of large scale sample panels of various parquets, and made plenty of intricate patterns to be installed by others. It doesn't take much movement over the entire field of a room to really make a mess of things. Another consideration......some guys will pre-raise the grain to before the final sand or padding but before sealing to avoid that sticky cat fuzzy grain raise, could be some went under the floor? Just thinking out loud. But I'm pretty sure at some point this previously decent parquet was made to or allowed to swell considerably. It moves, stresses out all the joints, pulls the cleats or nails around. Then, being California, things return to normal i.e. fairly dry, floor shrinks in every direction, you have gaps.

Any chance the floor was sanded then you had the wettest two seasons on record before finishing? Another possibility, you had floor sanded, you covered them, which does little in reality to stop moisture, taped and painted the whole house, which adds a lot of moisture to the air. I can remember painting my old house here in New England in the winter and having frost on the inside of my windows when I forgot to or refused to crack them a bit at the top. All that moisture from the paint leaves the walls, migrates to the floor. The buckling says floor swelled. When the tide recedes, it changes the beach on its way out.

[Charles Coolidge]

Also not to hijack the thread but what if a brand new oak floor installed in a brand new house cups within 3 months?

[Andrew Hughes]

We really haven't had much rain In california.New record for least amount for 2013. Everything is dry plants,trees wood floors my skin!
your floor will be fine when the rains come back.
My oak floors are pretty gapy too.

[Scott T Smith]

Also not to hijack the thread but what if a brand new oak floor installed in a brand new house cups within 3 months?

There are several potential causes for this, including the following:

1 - the flooring was not properly acclimated in the new house prior to installation. Proper acclimation includes stacking/stickering the flooring in a house with controlled RH% and temperature. This becomes more important as the width of the individual flooring boards is increased.
2 - the flooring was exposed to high RH% while in storage and prior to installation, and never dried back out.
3 - the flooring was not properly dried during manufacture.

Just opening up the flooring boxes may not be adequate for allowing it to lose MC%; sometimes you have to stack and sticker. Also, if new flooring is installed in a new house before the house's HVAC system has operated long enough to dry out the exposed wood in the subfloors, then problems can result.

[Charles Coolidge]

Thanks Scott, my money is on the flooring itself the house was built during the summer and I think there was maybe 1 or 2 days that it got wet before the roof was on so pretty much a dry build. Its 3" oak and looked perfect when I moved in. I keep the temp a constant 68 year round. Its not severely cupped but you can see it and feel it with your feet. I reported it to the builder under warranty, have not heard from the flooring company. Any chance it will equalize on its own cupping usually due to moister on one side and not the other right?

[Brian W Smith]

Two big problems with new construction(not directly OP's situation).HVAC,posted above,not being run......a lot,before flooring.When combined with material's mis-handling and a seasonal change,this can be a game stopper.

The next is more rare,but have seen it a cpl times.For whatever reason's.....concrete in a basement is left unpoured.House is in it's final stages,and still no concrete?Now,they pour the basement.....as posted above,large amounts of water is evaporated.It does not play nice with dry wood.A flooded basement is another example of large amts of water.

To the OP,I expect you had a cpl/several conditions that "aligned" and caused your problem.I'd be looking for a good HVAC co.,and get their advice on the climate control.Best of luck,BW

[Larry Edgerton]

How does one humidify the house and wont it eventually dry back again and cause the shrinkage?
i believe that i caused the problem. near the end of a major remodel, i had the floors sanded, covered with plastic sheeting then paper and taped closed. i thought i was protecting them from the painting that took a couple of months. the floors were slightly cupped in some areas but i had to live with it. chose a WB product and then the damage continued to show it self. its still occurring several months later. we're 1/4 mile from the ocean.

You are absolutely correct, here is where the problem came from. With plastic over water vapor collected under the plastic and swelled the floor. It probably would have made little difference if there was a finish on it, its the plastic that caused the problem. Your floor is not shrinking beyond what it was for 15 years now, its just getting back to that moisture level. It moved/swelled when it was under plastic, and it may never get back to its original fit.

Larry

[Jim Foster]

I would suggest you finish a test sample of a 2'x2' square or bigger and put the sample in the rooms the floor is in. I have not seen a WB floor finish that looks good when finished or over time, however a good quality oil finish looks amazing when new and over time. My experience is limited, but I let a floor installer talk me into Bonatech MEGA WB finish several years ago, and it looked like plastic when finished and looks worse now. I added a hardwood floor to several other rooms in the house and used Bona Woodline Polyurethane and it is in a whole different league as far as looks and resilience. I think the same manufacturer makes/own both finishes. Also, Walnut is a wood that I think improves tremendously in looks when treated with an oil finish.


Not to hi jack thread but going to have 1400 feet of walnut flooring in new house. Water base finish not the way to go??????

[Joe Hillmann]

On the bright side you won't have to sweep nearly as often as you used to. Where I used to live had no gaps between the floor boards and a polished finish. We would have to sweep every day at least. Where I live now has 1/16"-1/4" between each board and we may have to sweep once a week.

[Erik Loza]

We had our oak T&G floors re-done about 18 months ago, while the whole house was remodeled, and are getting some minor cupping and contraction in a sort of uniform way throughout the house. The flooring guys used a water-based finish. I asked about oil-based at the time (we considered using Tung oil...) but the GC's advise to me was that WB was easier to maintain in the long run, so we followed his reccommendation.

Honestly, I doesn't bother me. It's not like I'm tripping over the cups in the middle of the night. To me (at least...), hardwood floors have always had appeal exactly for the reason that they are imperfect and lend an element of character to the house. I know that some folks desire the whole "vast expanse of perfect smoothness"-look on a parquet floor or whatever but it's a wood floor and especially if you live in a climate that sees temp/hunidity swings, how much energy do you want to spend worrying about it?

Just my 2-cents as always,

Erik Loza
Minimax USA

[Leo Graywacz]

The GC should have said it was easier for him. It dries quicker so he can finish in one day instead of coming back three separate days for oil. I find that WB floor finishes don't last as long unless they are using a 2 part catalyzed finish like they do in commercial buildings.

[Jim Foster]

+1 on this.
The GC should have said it was easier for him.

[Erik Loza]

LOL, I'm sure. In and out in 1 day, one coat.

All that being said, no complaints with the finish. Still looks good and we have fairyly high foot traffic through the house.

Erik Loza
Minimax USA

[Scott T Smith]

Thanks Scott, my money is on the flooring itself the house was built during the summer and I think there was maybe 1 or 2 days that it got wet before the roof was on so pretty much a dry build. Its 3" oak and looked perfect when I moved in. I keep the temp a constant 68 year round. Its not severely cupped but you can see it and feel it with your feet. I reported it to the builder under warranty, have not heard from the flooring company. Any chance it will equalize on its own cupping usually due to moister on one side and not the other right?

Charles, if it were me I would check the RH% in the house and if it's low (below 40%), consider installing a humidifier in your HVAC system. If you increase the winter time RH% up to 50% - 60%, the cup may disappear.

[Leo Graywacz]

If it was only one coat then it sounds like he did a scuff and coat. He didn't grind it down to the bare wood.

And if he did I want to know what he used that you can only put one coat on and you are done. Usually you need a minimum of 2 coats. The first one needs to be scuff sanded so the second coat will be smooth to the touch.

[Keith Weber]

Just grout it!

[Jason White]

It's winter, so the air in your home is likely much dryer than it is during spring and summer. You should notice the gaps closing in a couple of months.


I've got a beautiful cherry Arenberg Parquet pattern floor in Los Angeles. It's about 15 years old. The house was recently remodeled and the oil based finish sanded off. The floor was refinished with a water based product. The finish was chosen because of it's quick dry and cure time. The immediate results were fine, but it's been about 3 months now and the floor has shrunk tremendously. It was previously so tight that you couldn't slip a piece of paper between the boards. Now it's open throughout and in some areas 3/16" wide. It's also apparently not finished shrinking, as it seems to continue it's process. There are no underground water pipes (in the attic). Any suggestions?