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