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.

Dark round pigmented areas

Q: I have sanded my old pine floor boards and finished with water based lacquer. Around the floor nails I am noticing dark round pigmented areas. Is this normal with reclaimed floors or is it because I used water based lacquer? I think maybe this is oxidation from the nail?

A: It sounds like a reaction of your finish with tannins in the wood. There are water based sealers designed to block such.

Gradually stain area until I can get it to match?

Q: We stripped and sanded our pine floors in our 100+ yr. old cottage.

Long ago, the previous owners painted around the large throw rug in middle of room. Eventually it sat for decades under wall to wall carpeting.

I was able to get three sides to blend with center but 4th side is much lighter than middle section of the floor. Do I try to sand this line / area to blend both areas or is it best to try to gradually stain until I can get it to match?

A: I would accept that this is the colour of those particular old boards and stain as normal. Old pine will offer a range of colouration and this is a natural part of aging.

Rug outline on newly finished floor in short time

Q: I had my wood floors refinished 2 months ago. I waited 3 weeks to put furniture and rugs down on them. I was vacuuming last week and rolled back the rug to vac underneath and found that there is an outline of the rug on the refinished floor. I don’t have a skylight or large windows, and it’s only been a few weeks since the floors were done. My floor guy has no idea why this has happened. The floors never had the original finish done over 30 years ago. Help please!

A: It would have been great if you posed an easy question. This is strange and not usual for native north American species of wood. Some of the more exotic imported woods such as Jatoba can change this rapidly. You allowed plenty of time before putting everything in place. Exactly what kind of finish was applied? Solvent or water based? Is there an under pad with this area rug?

1′ x 1′ Area where the wood is white.. or lacking stain

Q: I recently bought a 107 year old house. Upon ripping up the carpet I discovered beautiful, finished hardwood flooring. However, it seems (also told to me by seller) that the previous tenants (was a rental) had a dog (were not suppose to) and by the smell and sight, this dog went wee in the house.

There is a 1′ x 1′ area where the wood is white or lacking stain. Is this perhaps caused from the acid in the urine and soaking through? This is in the spare room, but I fear finding more of these spots, as this is a 2,200 sq. ft. home and mostly carpeted.

How should I approach this? Should I clean the floors first and restain? Clean and cover it with a rug? Only kidding. It also seems this house has had carpet for the last 21 years while in hands of last owner. He took GREAT care of this beauty, phew. Just need help with how to approach cleaning these poor suffocated wood floors. Thank you, in advance, for any help you may be able to lend.

A: Uric acid always makes the wood go black, not white. Black spots? You might have to change the boards.

Worn foot path won’t sand out

Q: I first did a spot sand on the worn foot tracks in a hallway of a pine floor and the sanding looked pretty good. Then it was decided to just sand the whole hallway for fear the spot sanding would not match the rest. After doing a full sanding and cleaning up the excess dust, I applied a natural stain to the floor. As the stain dried, you can still see where the worn foot tracks were prior to sanding. I am in a time crunch and would like to know if putting a 2nd coat of natural stain on the outer areas of the walk path would darken it up to blend in with the darker walk path or should I just keep sanding the worn path? I really don’t want to as the floor is pine. Thank you.

A: Okay, so old pine floor sanded and finished natural which had worn finish, exposing the wood. These areas are a different colour. I don’t think there is much you can do to change this. Apply 3 coats and be happy with the less than perfect appearance. It isn’t a piece of furniture and sunlight does cause colouration issues with everything.

Rug left area of Bamboo darker

Q: I have Bamboo flooring in my dining room and my grand room. We had an area rug in front of the sitting area and have now taken it up. It left that area of the Bamboo darker.

Is there any way we can get it to match the rest of the Bamboo?

A: The only way I know is to leave it exposed until it catches up to the rest of the floor. Some floors and wood will change more rapidly than others. Jatoba can show marked colour change in a week or two. It really is just a matter of patience and time.

It is not likely this bamboo has been installed for very long so you shouldn’t have that long to wait.

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.

Related Q: We had our floors refinished (sanded and restained) last summer. Since then, in the late fall, we began to notice lines forming at the seams between the boards and then in some places the finish is coming off.

A: I can only guess they used a water borne finish which tends to be less able to stretch. Heating season arrives, the humidity levels drop and wood floors may shrink slightly stretching the finish that has bridged from one board to the next. Now it fractures and may flake slightly at those fracture points. There are sealers designed to use with these finishes which can help prevent situations like this.

I would call the company who did the work and have them come and have a look and perhaps coat it again.