Do hardwood floors always buckle if there is a leak underneath?

Q: I have dark stains on my hardwood floor that I am noticing 3 years after a remodel. I suspect a leak, but the floor isn’t buckling. Do hardwood floors always buckle if there is a leak underneath?

A: A buckled floor would require a flood.

However, excess moisture often does cause some cupping with the board edges raising higher than the center when the water imbalance is from beneath.

Blue dye stains in hardwood

Q: I had a new red oak floor put down. At each board end, where the boards meet, there is a dark color developing, almost as if the oak were wet. What causes this, and should I worry about it occurring once the poly is down? Is this tannin?

A: It’s possible this is caused by microscopic fungal spores. You could do a search for blue dye stains in hardwood. I don’t think there is any way to get rid of it now that it left the drying kiln.

Somebody may also want to put a moisture meter on those areas to make sure it’s moisture is within specifications, 7-9%.

Sticky dance floor

Q: A charter school that I clean has a dance floor that was redone over the summer. They did not sand the floor, I believe they just resurfaced the floor. It is sticky. Dancers are sticking and falling. Any thing you could suggest to get the floor back to normal?

A: It couldn’t be floor finish itself which is still sticky. It has to be something else which has been applied, or found it’s way onto the finish. I would get a pail of Tie Tac cleaner from Poloplaz. It does an excellent job of removing contaminants. Mix some in a spray bottle and spray an area, then buff it with a polisher and white pad. After doing this to the entire floor, wet a towel with the cleaner and wrap it around a push broom. Go up and down the floor like a Zamboni machine, adjusting the towel to have a clean edge as needed.

Shellac was used to fill dip in floor?

Q: We had oak flooring installed, stained and a matte finish applied. A few months after a board dropped (under flooring board must have cracked or something) and left a 1/4 inch tripping hazard.

The floor guy came in and applied a shellac like fill which hardened well, filled the depressed area well, but is very shiny.. it looks like a patch of ice next to the matte finish. He has suggested that we sand it to dull the shine but we are afraid to do anything. Can you please advise. He seems unwilling to return.

A: Shellac like? I need to know exactly what he has applied. I can’t imagine why he would apply a shellac over a polyurethane. If it is shellac which has not been de-waxed (shellac naturally contains wax) no finish will stick to it.

Is the sub floor accessible from below? For example, from the basement?

It is possible to dull a coating by rubbing with either very fine steel wool, say ‘0000’ or a super fine sandpaper such as 500 or 1000 grit. You get the idea.

Stain on bottom of socks after refinishing

Q: We refinished 100 yr old redwood floors, 1 coat stain, 3 coats polyurethane. After 2 days, when we walk across it in socks afterwards we can see stain lines from some of the cracks on the bottom of our socks. Why is this? Will it eventually dry?

A: That isn’t something you want to see happen. And this after also applying 3 coats of polyurethane. You must have applied the stain quite heavily, possibly with a lambswool applicator. I always strap on the knee pads and apply it with a cloth, row by row. And after applying to each row you go back and wipe off the excess. Also, if you had used a fast dry stain such as Dura Seal Quick Coat or Poloplaz stains it would have totally dried.

You’ve gotten probably a significant amount of stain between the boards and because it isn’t getting exposure to fresh air it is having trouble drying. This will become even more aggravating if the polyurethane is also not dry and starts to appear on the board edges as little beads. I think I would start by having a fan blowing directly on the floor to try and force dry it. You might also dampen a cloth with mineral spirits and wipe suspected board edges.

Minor chips and splinters on floorboards

Q: I have an engineered hardwood floor and the relative humidity in my house is between 45 to 55%. The hardwood is within 2% of the subfloor moisture content. The installation was done by a reputable professional that I personally know and have seen his work over the past few years.

The problem is in about 500 total square feet 30 or so boards have gradually exhibited minor chips and splinters, mainly on the edge, but a few in the center. Other than installation error could this be some type of product defect through milling or green wood not being cured properly?

Any other ideas or anything I should look for to determine if it’s a manufacturer defect or installer error?

A: I would be approaching the manufacturer with this problem. I know of no reason this would have anything to do with the installation or installer.

Repair job looks very bleached

Q: We used peroxide to bleach out some urine stains on our wood floors, then sanded them, and conditioned those spots.

The rest of the floor has the polyurethane coating that was put down years ago, while the spots are very bleached.

I’ve tried every color, trying to match up the sanded down spots to the rest of the finished floor. Nothing works. Everything is too light. I even bought Waterlox, but the sanded down areas are still very light.

I’m hoping you can help me figure out how to match up the color.

A: Honestly, I think you are searching for something that is not possible. If you are working in the middle of the room, I don’t think you have a chance of blending this in. I can offer a few tips.

First, you want to deal with entire boards. You don’t work on half a board. One technique to make stain darker is to water pop. After you have sanded the boards in preparation, finishing with 100 grit, wet the area and let it dry. This will open the surface and allow for a darker color. But don’t expect to achieve an exact match.

People typically want to sand the wood with far too fine an abrasive which closes the wood surface and won’t allow proper penetration of the stain.

Follow-up: Thank you so much. And you’re absolutely right about it all. I tried everything and just gave up. Today I used the stain knowing it wouldn’t look great.. just to get it over with. The room has an area rug, and I will just put it back to cover it up.

Stripes where blue painters tape was

Q: I just had oil finished hardwood floors installed. The installers used blue painters tape to hold the boards down and together while installing. When they pulled the tape from the floors it left stripes. They have cleaned the area of the tape residue, but marks are still visible. Is there a way to fix this without pulling up all the damaged boards?

A: If this is an oil finish, perhaps the manufacturer has a recommendation of what to apply to freshen up the oil finish. Perhaps the tape pulled at it and left dull strips? Or, depending what kind of wood it is, some exotics change color rapidly with light exposure and if the tape was left down for several days this may be the result. If that is it, not to worry. The lighter area will catch up.

Sump pump flooded laminate floor

Q: My sump pump failed and flooded my in-progress reno. The laminate floor has bubbled in about 25% of the floor. I will replace the floor eventually, but I’m really not up for doing it now. The water was on the floor for about 5 hours.

I vacuumed it up and sucked it out. I have my heated floors on. Will the heated floors dry it out from underneath? I have heaters in the room and a dehumidifier on which has brought the air moisture from 46% to 30%. Is it a health hazard to leave it? Will the in-floor heating dry it out?

A: The thing with water is it doesn’t just disappear if we turn up the heat. I would pull it all up because if the water cannot escape into the air it will be a great environment for mold development, especially with the increased heat. Mold loves warm and wet.

Finish on repaired area looks much duller

Q: We have a wood floor in our kitchen, with a satin finish. Our wood floor contractor tried to repair an area on the floor where the there was some damage. The problem is the finish on the repaired area looks much duller than the rest of the floor. How can we match the finish?

A: It can sometimes be hit and miss when not working from the same batch of finish. If it is duller I don’t know of anything short of trying to coat again.

Similar Q: We just laid unfinished red oak hardwood floors. After staining and 2 coats poly the floors looked pretty good for non professionals. My question is – I noticed a couple of problem areas that I wanted to fix, after sanding and reapplying stain and poly, and after everything dried, the fixed areas are a lot shinier then the rest of the floor (used the same poly). What’s the best way to fix and match the shine to the rest of the floor? Do I just need to resand the whole area?

A: I assume the finish is perhaps a satin, semi or matte finish. For most or many of these products, the paste which is added to the polyurethane needs to be mixed in well so that it is dispersed evenly throughout the product. The only finish I’ve used which doesn’t require much stirring is Poloplaz Primero. Having said all that, it is just about impossible to get an invisible blend on a patch in the middle of the board. The best we can hope for is to lightly but thoroughly sand the entire boards involved with a fine abrasive. After removing all the dust, tape off the boards along the edges, apply a thin coat of the well stirred finish and immediately remove the tape. Don’t let anyone step on it until it’s dry. That is easier said than done.

Light (UV?) areas appeared on floor after applying poly

Q: I have just resanded and finished my 15-20 year old red oak floor. We stained it a week before putting on a water based poly, and it looked great before we applied the poly.

Once we applied the poly finish, light areas appeared on the floor. They appeared where the light has come in from the sliding door and windows. Can UV cause the floor to lighten within the week before applying the poly finish? We left the blinds open, but there was only a day or 2 of sunlight during this time. Or is this just a result of years of UV light damage?

I’m not sure I can live with it the way it is, so what are my options? Resand/restain a lighter colour?

A: When the floor was sanded to clean wood did you notice a shading difference?

If you can’t live with what you have the only chance to change it is sand again. I would use a stain which I know dries reliably and quickly such as Dura Seal Quick Coat. if it is a darker colour, water pop the wood first. This means wetting the floor surface to open the grain, allowing better stain penetration. Then start applying finish coats the next day.

Spot treating a dent in floor

Q: We recently had our floors sanded and refinished. We used a Bona satin finish (the one with the hardener). It looked really nice and then a coffee cup with metal left a large crescent shaped dent in 2 boards. My husband has attempted to fix the affected 2 boards by sanding, restraining and applying the topcoat with a stain brush.

He is on the 3rd coat and it’s really highlighted. It does not look the same thickness at all. Is there any suggestion you can give us with spot treating?

A: The finished used was Traffic? Make sure it is well stirred first. Thin coats are generally better and recommended than thick for curing reasons. Water borne coatings also are not generally considered high build either. That is one way of saying the urethane solids content in the finish is less than an oil/solvent based coating. I would put blue painters tape around the area to be coated. Do the entire boards affected. Lightly sand as needed (an abrasive pad works well for this. Don’t use steel wool). Coat the area enclosed by the tape and then remove the tape before it dries. There is no guarantee you can get an invisible patch with top coats but water based finishes are generally a bit more friendly in that regard than oil based.

Stain appears to have been applied over polyurethane

Q: My daughter bought a house with stain that appears to have been put over the polyurethane several years ago. The stain is now scratched and looks horrible. Any advice on how to remove this stain?

A: This floor needs to be sanded to clean wood and done over. Applying a stain on top of a surface coating such as polyurethane is not going to work. Stain is meant to penetrate into the wood surface with finish on top of it.

Water and snow has damaged finish by front door

Q: My floor is beautiful. It’s approx. 10 years old. My problem is in front of my entrance door.

Entering directly from outside and stepping onto the floor with water and snow has damaged the finish. I have some pitting and deep, dark spots in front of the door.

What is best, least expensive way to fix this 2′ x 2′ area?

A: If the dark areas indicate bare, exposed and now discoloured wood because the finish has so degraded, then the area may have to be sanded to bare wood and finished over.

If you can tape off and restrict this sanding to precisely the boards affected the end result will look less like a patch, though you may have to finally buff and re-coat the entire room to get a better blend.

Can water popping cause cupping?

Q: Can water popping cause cupping? Out Southern pine floors were installed and sanded. Then they water popped the floor to apply stain, which ended up looking very good. Sadly the floors looked cupped almost right after the finish was done. Since the process between the installation and finish was so quick, I’m not sure if my cupping is caused by the humidity in the house/crawling or if there was something wrong with the staining process.

A: I water pop hardwood often, especially when working with darker colours. I never do so with soft woods simply because it can take much longer to dry and because the wood is soft, I don’t feel I need to water pop soft woods to achieve the desired colour.

Having said that, I don’t believe there is much chance water popping could cup your floor. Water popping is simply wiping the surface of the floor with a wet cloth to make sure all the surface is wet, not soaked. How did they wet the floor?

Are there a lot of significant gaps between boards? I ask this because cupping occurs when there is an imbalance of excessive moisture coming up from the bottom of the board. Crowning (the middle of the board is raised higher than the edges) occurs when it is the surface of the floor which has received excess moisture. So, unless they really soaked the floor and water was able to seep between boards to the sub floor I don’t see water popping being an issue.

Likewise, and again depending on gaps between the boards, if they used a water born finish and applied several coats on the same day I could see that potentially causing a problem. It seems unusual for pine to cup. I’m not sure I’ve ever seen it happen. But it is not unusual for it to suffer significant shrinkage after being installed.

What is beneath this floor? If it is a crawl space that is damp, wet or humid that would be my first suspect.

A couple of additional questions. Was this pine left in the house for a time, say a week or two before being installed? Do you know if they happened to check the flooring and the sub floor with a moisture meter before installing? Do you live near a significant body of water, say the ocean for example? In such cases acclimation of wood to the environment takes on even greater importance.

Follow-up Q: Thanks for your answer. There are pretty much no gaps in between boards, all boards look pretty tight together. Was there supposed to be a gap between boards at installation? if so, how much? I saw the water popping process and they didn’t use much water so now I’m thinking the installation was done incorrectly or my crawling space is too humid.

To answer your other questions. I don’t live near the ocean or lake. The floors were in the house for a couple of weeks before installing. They didn’t not check the humidity of the floors and crawling as far as I know.

Here are a couple more details to narrow it down: The floors were installed in North Carolina in December and the house was vacant at the time with construction going on so the heat wasn’t running very high during the process. Maybe between 55 to 65 degrees. My crawl space doesn’t feel particularly humid. What is the ideal humidity for the crawling space and floors to be back to normal state? Once again thank you for your time.

A: Some gapping would be expected as normal. Great if you have little to none. This is not caused by water popping. I would focus on the crawl space. Have you had the installer come back to check these things out?

Water damage from flower pots

Q: We had a flower pot in the dinning room, on a rug over our hard wood floor. When I picked the rug up I discovered some of the floor has darkened.

A: Sounds like this has happened over a long period of time to cause water damage like this. You will likely have to replace the damaged boards to make this spot go away.

Related Q: I recently over-watered a plant in our living room and it overflowed onto our hardwood floor. Before I noticed it, I happened to go into our garage (which is directly under the living room) and found that the water was pouring out from the underside of the floor. Should water just flow straight through so easily?

A: One would not think so but clearly the water found a way between the boards of your hardwood floor (that means you have pre finished or some significant gaps between boards) and then found another gap in the sub floor; whether your floor is sitting on plywood or is a much older house with pine or spruce plank sub floor.

Similar Q: Can spilling a glass of water on a hardwood floor, yet wiping it up within 5 minutes, cause the floor to crack?

A: I don’t know what you mean by crack, and I assume this floor has some sort of finish on it. I would consider this event insignificant.

Wax to stop the creaking sound?

Q: What can I do to stop the creaking sound my wooden floor makes when you step on it? I heard that you should wax the floor.

A: You shouldn’t wax a floor if it is finished with a polyurethane or similar top coat. Waxing won’t stop the creaking in any case.

The movement in the floor is very likely also related to a loose and moving sub floor. The only sure way to remedy this is to replace the floor. Nail down the old subfloor with spiral nails and if need be, screw at least 3/8 spruce sheeting over top, then a new hardwood floor.

Related Q: We installed hardwood floors in our house 2 years ago. We used all short boards. It looks great, but the whole floor pops as we walk across it. I thought that maybe it was because we have so many joints, having used the short boards, but we have no idea how to fix it.

We put a new layer of OSB down since taking out the old floor left the original subfloor weak. Do you have any suggestions on how to fix the popping?

A: If the problem is the OSB no holding the nails, there isn’t much you can do short of removing the floor, installing plywood and then installing the floor again. Perhaps you can fire the occasional 2″ nail from a trim gun and putty the hole, but I’m not very hopeful that will work.