A Mysterious Wood Problem
I’m trying to restore an oak hardwood floor in a house built in 1954 in Akron, Ohio, near Cleveland. It was covered with carpeting. I don’t know for how long. I have sanded it down to bare wood. Some stains, which seems to be from water, still remains as it has penetrated the wood. I’m okay with that.
I left it in this condition for about 8 months– from last fall to until now. The house was empty and closed for all these months. When I went to the house about a month ago to resume work there to refinish the wood floor, I was surprised to see that the water stains had darkened and in some areas there was actual water over the stain! I could not find any source of the water. The house was in perfect condition, no leaking of water in any place and the plumbing was on the other side of the house. There is no plumbing anywhere near or under that floor.
I wiped the floor with all the windows and doors open to make it dry again. I also rubbed off the darkened areas, which were damp, with paper towel that made them lighter. Not knowing what to do, I postponed the work for a few days. It rained most of those days. So when I went back to that house, I found those same spots darkened and damp again. And they lightened again after some rubbing with paper towels. It has been going on for the last few weeks. Whenever it rains outside, those areas of the hardwood floor become damp again and the stains darkened. On sunny days they somewhat lightens on their own. This is the situation.
I asked several woodworking experts including hardwood floor finishers and re-finishers. Nobody could give me a satisfactory explanation. Most of them were surprised and told me that they had never experienced anything like this.
I wonder what you people know about it and what you suggest to solve the problem.
Initially, I thought that the wood was attracting moisture from the damp air. So after I finish it, the bare wood will not be exposed to damp air and so will not be attracting water. But being an environmentalist, I am finishing the wood with hundred percent pure tung oil and citrus solvent. I didn’t know if tung oil will create enough of a barrier to protect the water from moisture. So I finished a section of the floor with one coat of tung oil and waited for a rainy day. The water stains there became darkened and moist again after the rain– although it seems a little less than the bare wood. I wonder if several coats will protect it more. Or I have to add a coat or two of polyurethane over tung oil. Or maybe even polyurethane will not stop the bleeding, because the source of the problem is something else.
Your considered explanation and advice will be highly appreciated.
It's vaguely possible that the wood is contaminated with sodium hydroxide or some similar hydroscopic chemical.
Consider whether these locations where there might have been, eg, a china cabinet which contained a can of moisture absorbant such as "Arm & Hammer Moisture Absorber and Odor Eliminator". If left unattended these things can overflow and drip the absorbant onto the floor. (And, obviously, if tipped over they are even worse.)
Note that this would likely leave a whitish area where the stuff has soaked into the wood.
If this is the situation then you need to thoroughly rinse the problem areas, flooding several times with enough water to get the stuff out of the wood.
You have a leak somewhere. Whether you can see it or not you don't get standing water from condensation. It could be coming from a window, down the wall framing or even across the floor, but something is leaking. Trying to refinish it before finding the leak would be a waste of time. Tung oil will not keep moisture at bay for long.
I agree that a leak is the most obvious source but dont rule out that there is air condition duct leak blowing right underneath that spot. . The right combination of cold air hitting one spot and hot moist air leaking in could result in condensation or it could be that the condensation is coming up from below. My advice is, drill the smallest hole you can and thread a wire through it and go below and look in that area. Maybe their is an air duct getting so much condensation that it is wicking through both the subflooring and the problem with the from below theory is that the water would most likely continue to diffuse outward to other ares and not pool up on top. But I would still drill the hole and look underneath too...you'll never see the hole after you finish it.
To rule out a leak, positon a table or chair over a few of the spots (with a plastic bag or some such on top to catch the water).
We had a dog that would P everytime you looked sideways at it.....perhaps you have a timid ghost that lets loose everytime you enter the house
Of Course, with a ghost, you usually scare the SHEET out of them.
Again, I'm strongly suspecting some sort of hydroscopic agent. I've seen this a few times.
Another case of lots of words but not the needed details
HARDWOOS floor - WHat type hardwood.
Per Dan, may be hydroscopic, I have had raw BIRCH floors and even cabinet panels stain and show dampness because of the hydroscopic nature of birch.