Manufacturer claims stains caused by hardwood floor cleaner

Q: We had an engineered wood floor in American Cherry finish installed throughout the Living, Dining, Family Rooms and Kitchen (1000 sq. ft., open concept) about one year ago. Approximately 6 months ago we started to notice dark stains appearing along the edges and ends of the planks, which we assumed to be water stains.

The house is 30+ years old, concrete slab on grade, which was previously carpeted. In some cases the stain spans across the width of the plank (3 1/2′). We contacted the installer who advised us that he had never seen this before and had the manufacturers rep visit for an inspection.

The manufacturer now says that these stains are caused by our use of hardwood floor cleaner, which we purchased especially for these floors. We maintain that this cannot be so, we are very careful to follow all recommendations regarding maintenance of these floors.

We use the cleaner infrequently, spray only a small amount directly onto the mop and ensure that the floor is dry after use. In addition, we have never cleaned under the area rugs with cleaner, and yet the stains extend under the hall runner. They also appear to be localized in the hallway and living room areas which indicates to me that the material used in these areas may have been wet when installed. I also cannot understand how any floor cleaner could have penetrated across the full width of the plank as it has done in some areas. We need advice on how to handle this problem which we believe is getting worse.

A: Very interesting problem, but not funny! Like yourself, I don’t believe using a recommended floor cleaner will cause this problem. Even if you misted a small amount onto the surface of the floor from a spray bottle, you shouldn’t see this problem. And you aren’t doing that, but spraying onto the mop first, which is the recommended way.

These floors are top coated with, probably an aluminum oxide finish, is that correct? Any evidence of finish peeling or degradation? I’m leaning toward this being a defective product.

Is there any chance this black marking is mold?

Yellow patch appearing on pine floor

Q: In our bathroom we have 30 year old pine floorboards that had previously been stained and varnished. I stripped the varnish off and sanded to reveal a nice distressed look. Then I used Sadolins floor oil. The result was very good. However, a month later I have a yellow patch appearing (about 8 by 8) and I can’t get rid of it. I’ve tried sanding, but the yellow only seems to get brighter. Do you have any idea what caused it and how to remove it? I don’t want to replace the planks.

A: It sounds like something was spilled on the spot and has either reacted with this oil finish or soaked past it and discoloured the wood itself. I would suggest contacting the finish manufacturer to see if they have any suggestions.

Brazilian Cherry darkened in under 2 months leaving lighter spots where furniture was

Q: A contractor just installed around 800 square feet of 3/4 prefinished Brazilian Cherry on our first floor. It looked very good until we unstacked our furniture today.

The furniture had been sitting on top of flat pieces of card board for about 1-1/2 to 2 months as the contractor finished the floors. Now we find that our floors look like they got a sunburn with band-aid marks all over them! We knew that Brazilian Cherry darkened with time and that the furniture would need to be moved around, but we never thought that in under 2 months the floor would change so dramatically. We have now uncovered all the spots that were covered with furniture and card board and we’re hoping that the lighter wood will catch up to the darker wood.

Which brings me to my questions: Will the light areas darken to blend in over time so that it will be completely unnoticeable? Or, will there always be a line where our furniture laid?

If the latter is the case, do you have any recommendations for us? We spent so much time and money on this project that this is really upsetting. Any guidance with this is appreciated!

A: 2 months? You would have that change in 2 weeks. Don’t worry about it. The lighter patches will catch up as they are exposed to light. The floor will not keep getting darker to infinity. The lighter areas will change soon.

Spots where I used oxalic acid (wood brightener) are lighter after finishing

Q: I have just completed refinishing a 55 year old white oak floor. To remove some water spots I used oxalic acid (wood brightener). It looked great when the wood was raw, however, the water based urethane made these areas appear lighter and bleached out in appearance.

How can I have these area blend into the surrounding floor boards?

A: I think you might have to accept it and live with it. What are the options? Sand it all down again and either bleach the entire floor or stain it. How thick is the wood? It may be too thin to take this amount of sanding.

Dark spots on floor hot to touch

Q: We bought engineered bamboo hardwood flooring in February and kept it in the house until it was installed in March. It was glued down with the glue that the store recommended. Now dark spots are showing up in certain areas of the kitchen. Bubbles are now appearing on the darkened areas and the wood is hot to the touch. This part of the floor does not have a full basement, but does have installation and subflooring. There does not appear to be any moisture anywhere. What could be the problem?

A: I’m not certain what is going on. That you say the spots are “hot” may be a clue. Is there some type of reaction going on between the adhesive used to install the floor and the adhesives used in the floor itself? I would definitely be calling the company you bought the floor from and have them come and inspect it.

Discoloration of wood floor, from sunlight

Q: Twelve years ago our white oak floors were installed and stained on-site, then finished with “Glitza”. I foolishly had a large area rug in dining room where it is sunny.

We are selling and a “stager” said to remove the rug. And now from either sun or mopping or both, the under-rug area is a darker golden. Not horrible but the discoloration is definitely noticeable. Suggestions?

Our home is quite large and fairly expensive asking price, so a buyer will be understandably bothered by this issue. We won’t hide this from buyers yet would like to minimize the variation if possible, and unfortunately we simply can’t afford a major fix. Is there a wood bleach or something that would help blend the lines?

A: I wish I had a magic potion to fix this but unfortunately time alone can do so. If it is very severe it is possible that it may still show slightly even if were totally sanded. I would look at it this way, and I’ve sold enough houses to know: I wouldn’t worry about it too much because there is a good chance that whoever buys the place likely won’t like the colour and has already decided to have the floors stained a different colour. It’s much more important that they are structurally in good shape which they no doubt are. Real estate agents will have people doing all sorts of costly things to sell their house, and believe me, in the end it was all money spent for nothing because the buyer will change everything you have upgraded.

Follow-up: Craig, I so appreciate your quick and kind reply! You make some very good points and helpful points, too. While I certainly wish there was a quick fix it is good to know from an expert that there is no such thing besides time, and therefore keep me from trying some extreme and potentially further-damaging measures. It also helps to suspect that even sanding could potentially result in a remaining shadow of the same issue. Finally, you’re so right that a buyer will no doubt want to change more (in the home we’re emotionally-tied to) than I care to even think about, so it’s probably time to let go. Thanks again very much.

A: Not that I want the last word but when you said you were emotionally tied to your house it struck a cord with me. I moved from my family home in Toronto in June 2009 when the financial melt down was occurring. My grandparents bought the house when I was 4 months old. I grew up there and finally came into possession of the house. Never wanted to leave. Never planned to leave. But I felt it would be worse to lose it because I’m caught in a melt down I can’t control. We moved to Niagara on the shores of Lake Erie but for 5 months I was still driving over 200 miles a day doing floor jobs, until I couldn’t stand it any more.

One day I had some time to spare so I thought I would go to the old neighbourhood to see if any neighbours were around and to look at my family home. As I sat in my van on the street for a minute a strange feeling came over me. ‘I don’t belong here any more’. I realized it isn’t the house. It’s the memories from living there. In other words, the building is a pile of bricks. It was the family and all the gatherings that occurred there. When the family is gone the house is a pile of bricks. We have since left Niagara and now live in the bush in a tiny cabin with an out house and have bears passing through our yard. And deer. I waited 60 years to be a few feet from a black bear in the wild! That’s a memory! You will make more too.

Related Q: My husband has been in the wood flooring business for 20 years and is a 3rd generation wood flooring man. He recently sanded a heartpine floor for a customer that had several area rugs and furniture, under the rugs the flooring was lighter. After sanding far more than usual the dark uncovered areas are still not as light as the areas that were covered and lighter to begin with. This is the first time he has come across this issue.. any thoughts or suggestions? The customer does not want to stain the floor and would like it as light as possible.

A: This is clearly not his fault. We can’t totally control nature. If the dis colouration won’t sand out they will simply have to leave the area previously hidden by carpet exposed for as long as it takes. I wish I knew a magic trick for this problem but I don’t. If I see this when doing an estimate I always make sure to give a disclaimer because it is impossible to know if it will come out with sanding.

Similar Q: I had a piece of carpet upside down on my hardwood floor. Now I have variation of color where the carpet was and the rest of the floor. Is there something in the carpet that would cause this, or would the other part of the floor fade?

A: This is caused by sunlight. Some species will have a change like this after as little as a week. Leave the area uncovered. It should equal out.

Pale spots on pine floor

Q: I’ve just had a 100 yr old Kauri pine floor sanded and finished with a 2 pack water based polyurethane. The sanding looks fine and the finish is great, except that there are pale spots / blotches evident in the wood in a number of areas, some quite large, some small. These were evident after applying the sealer, but I was assured would disappear with the urethane finish (4 coats) but they haven’t, and then I was told this sometimes happens with Kauri pine. This doesn’t sound right to me. Are you able to confirm what is the likely cause and if it can be rectified?

A: This pine is native to New Zealand so I’ve not worked with it. However, it is probably much like other pine in that it contains resins. The presence of the resins can vary from piece to piece. You likely are getting interaction between that and the finish. Unless there is a sealer which can be applied to block that there isn’t much to be done except live with it and consider it natural for that species of wood.

Bleach like spots on wood floor

Q: I have pine wood floors coated with polyurethane. They are about 80 years old. Some of the wood, usually under a bed or throw rug, has lost it’s color in spots. It’s the wood itself, not the coating. It looks like bleach has taken the color out of the wood in streaks, bleach like spots on wood floor. Sometimes small areas, sometimes large. What could be the cause and what’s the cure for this? Thank you.

A: I don’t know for sure. It sounds like ultra violet bleaching.

Note from Webmaster: here’s an article titled “Fading and Damage from UV Exposure” that states “Color deterioration in wood floors occurs from three sources: UV exposure, heat and moisture.”

Dark spots a sanding issue or resins?

Q: Before applying finish to my fir flooring, I want to know whether my fir floors have been properly sanded. There are numerous areas of darker color, for example, a 3-inch band of darker wood parallel to the wall and offset by about 6 inches. It seems like this strip simply was not sanded as much as it should have been. Other dark areas with pretty well defined edges are in the middle of the floor. How can I be sure these are sanding issues and not due to some other cause?

A: Try a hand scraper on a couple of them and see if you can scrape it lighter. If not it is just resins or some extractive in the wood itself and not old finish.

Carpet stain cleaner caused yellow spot on wood floor

Q: We have new hardwood flooring with 3 coats of crystal finish. Our dog was sick on the area rug so I used (Spot Shot) carpet stain cleaner on the carpet only to discover that the floor under the area where I used the carpet stain cleaner is now a bright yellow. How can I remove this bright yellow stain from my new flooring?

A: I think your crystal finish is a low end water borne polyurethane. The product you sprayed on your carpet is oil based and probably contains silicone. Not a good match. I would try denatured alcohol or such to remove the discoloration but I doubt it will work. You will probably have to have at least the boards affected taken down to bare wood and re-finished.

Spot finishing grey areas

Q: My mom’s floors have well travelled areas (like doorways) where the floors look almost gray. The floors are otherwise light. How can the well travelled areas be repaired to look like the rest? Is there something we can put on it? Can I spot repair wood floors?

A: The floors need to be totally sanded and finished from scratch. The grey areas are that way because the finish has been totally removed, exposing the wood to the elements and effects of day to day living. Trying to patch the area won’t give you a good blend with the rest of the floors. If wooden floors are finished with proper techniques and good finishes, and given the usual care and maintenance that any floor covering would require, this sort of situation should not arise.

Similar Q: I’m redoing my floors and I tried to “spot sand” a couple dark spots. For the rest I lightly sanded the poly. I’m now worried that the sanded spots will show lighter than older aged, more yellowed poly floor. Is there anything to do short of sanding whole floor evenly?

A: Not really. It might help to sand the entire board rather than just a spot. Duplicate on the entire board what you did with the spots, then apply painters tape around the board joints, apply a thin coat of finish and remove the tape immediately. Repeat.

Grey and worn areas on floor

Q: The heavy traffic areas of my floor are worn down and grey. Can I just clean-up and re-varnish those areas and blend them into the rest of the hardwood floor? I know it won’t be perfect, but will it be OK?

A: The grayed areas will have to be sanded to bare, clean wood and then finished. To apply a finish over that would make the spots look black.

Similar Q: I have some very worn spots on my floor. Can just those spots be repaired, or do I need to have the whole floor refinished?

A: It is about impossible to do a patch and have it blend, unnoticed. This is especially pronounced with age. So, you will need to have the entire floor done unless you are content to live with a patch.

Lighter color in seams of hardwood

Q: This past summer we purchased a 50-60 yr. old home, ripped up the old brdlm. to expose the hardwood floors. We also had to add hardwood floors to a room that had a addition added. We wanted to stain a dark chocolate brown, so we hired a company to sand/refinish. When they initially looked at the floor, they said floor is nice and thick/never been sanded. Our 1st problem was the installers did not let the 2 top coats (sealer/etc.) dry completely because it was very humid and they told us it was okay to move in. We have buff marks all over various parts of the house from the buffer sticking. (We were compensated for this problem.) In December we noticed between the seams of the hardwood floor you can see gaps/lighter color. Even on the new hardwood that they installed. The company came back again and said it was expansion/contraction and low humidity in the house and because the hardwood was covered with brdlm for years (At one time the hardwood was exposed.) No one told us at the start that the floors could do this, we have never heard of this, and if this was told to us we might have gone with a lighter color. Would love your opinion on this matter.

A: Polisher swirls are generally a problem when finishing with a gloss finish. It is a tough problem because previous coats may need to be abraded to gain adhesion, depending on the finish used. They don’t usually show up in low sheen finishes. Did you have water borne or oil modified applied? I ask this because water borne don’t stretch as well as oil, and if the floor shrinks the water borne will fracture and can leave what looks like white lines along board edges.

After the finish was applied, dark spots appeared

Q: Some friends of ours had their hardwood floors refinished by professionals. The floor looked perfect after sanding, before the finish; but, after the finish was applied, dark pet spots appeared. I am refinishing my floors and I don’t want the same thing to happen. My sanding is complete and floors look good now, but is there the chance that the same will happen? Or was something done incorrectly to cause this to happen to our friends floor?

A: There is no way “pet stains” can be sanded away and disappear, then re-appear. They are either gone or they aren’t. If they aren’t, you will see them on the freshly sanded wood.

Perhaps these black marks are the result of “tannin pull”. Occasionally a floor, particularly white oak, can have high levels of tannin which can react with the floor finish and leave black marks. I’ve only seen it a handful of times in 34 years.

Similar Q: My friend had her floors refinished and some dark spots have appeared in the days that followed. Any idea what can cause this?

A: Wild guess? A tannin reaction in the wood or there is a moisture problem under the floor.

Follow-up Q: I looked at the bottom of the floor from the basement and didn’t see any moisture. Do you know of anything that can be done to fix it?

A: If it was a tannin reaction, the spots would need to be sanded out and a sealer applied first that is designed to help prevent this. It depends the type of finish that was used. If it is an oil based coating, a universal sealer (de-waxed shellac) could be used. If water borne, then a water borne sealer.

Besides sanding the dark spot out, I don’t know. Maybe just the board(s) involved could be sanded, taping off around the board to isolate it from the ones beside it. Then coat it and remove the tape.

Similar Q: After removing carpet I noticed there were some dark spots in the wood. I sanded the floors, but the spots are still there (a little lighter than before). what can I do to these areas before I stain the floor?

A: Either change the boards or if you think the stain is dark enough, just stain and finish which should hide the dark spots.

Footprints permanently in the urethane

Q: My Apt. has fir floors that were refinished in the last year or two. They are maybe 90 years old. Footprints permanently in the urethane (bleeding spots). They appeared one day a few months ago after I moved in. Sanding with fine grit paper doesn’t take the spot (tread mark) off. I have no idea what was on the shoes, no chemicals are in the house. It could have been the maintenance man, but I’m worried about my deposit. Appx. 30 footprint/tread spots. It looks like the floor was refinished by amateurs, but they are a showcase item to them. Nobody has any idea what to do about this. Help!

PS Would rather fix it than get maintenance involved. Already had an incident where maintenance man ground grease from his boots into a throw rug of mine while working in the apt.

A: It sounds to me as if the workers walked over the finish when it wasn’t fully dry and left foot prints. If this happened on the first coat, the only way to remove them is to remove the finish down to and past the marks…which essentially means starting over. It’s quite possible the floors were done by low ball hacks. Cheap price. Fast job. Zero quality.

A few boards shinier than the rest of the floor

Q: I just had my hardwood floors refinished and the contractor came back a few days later to do a touch up. He has left a few boards shinier than the rest of the floor, and the lighting in the house really spotlights it. Is there any way to diminish the shine on a small area?

A: If he used a satin finish, he will have to make sure it is well mixed. For the boards that are too shiny, he will need to buff with a fine abrasive or steel wool (unless he used waterborne, then do not use steel wool) to remove the gloss. He needs to carefully do this to each entire board that is affected. He probably should apply some painters tape along all the edges so the finish doesn’t get on adjoining boards. Clean all dust off and apply a thin coat.

Dark stain circles on very old floor

Q: I just moved to an old house from the 1800’s. The wooden floor is very old and has very dark stain circles on it. I have tried getting it off with soap and water. It wont come off. I was told I can’t sand it because it is too thin. Is there a dark enough product that can cover it to still make it look like wood, or is there something that can take out the stain?

A: Not that I can think of. If, and it is likely, that this is a wax finish, a product called Renovator by Dura Seal will help to clean it up. I doubt it will remove the water marks. www.duraseal.com

Nail holes with black rims

Q: we are redoing oak hardwood floors in a 1959 bungalow. When we do this we will be removing a small floating closet that will have nails through the floor. How do we remove the black marks from around the nail holes before we fill them?

A: Those black marks may not actually come out. If they bother you excessively, you could punch down or recess the black area and fill with wood filler.

Fixing darker pieces

Q: I had a new real wood floor installed in my living room which abuts the hallway, which already had wood flooring. It is a close match but there are maybe 25 to 30 slats in the new floor that are of a darker shade than any slat on the old floor. Only the first coat of poly has been applied. Is there any way to get the darker slats lighter and to blend more with the floor that was already there?

A: The only way is to replace the pieces you don’t like.