Can I apply more layers of varathane without sanding or screening them first?

Q: My house was built in the 1780s. It still has the original wide plank flooring. When I bought it 15 years ago, most of the floors were covered in paint, asbestos tiles and linoleum. I pulled all that up, sanded them down and applied 3 coats of oil based varathane.

The wood is pine and having dogs running around has taken its toll. Can I apply more layers of varathane without sanding or screening them first? I don’t care about imperfections just don’t want the wood exposed.

A: You will have to abrade the existing coating first to gain adhesion, whether you use a polisher and screen or get down on hands and knees with fine sand paper and lightly but thoroughly sand the entire floor. Before I did that I think I’d wipe the floor down with a good cleaner such as Poloplaz, Basic Coatings or Bona Kemi makes. This will remove any contaminants such as oils or other residues which may have gotten on the finish and can cause adhesion issues. Thoroughly abrade all the finish. Vacuum up the fine dust. Wipe down with a micro weave cloth and apply coat.

Removing glue from cement

Q: I’ve recently ripped up engineered hardwood that was glued to plywood. We also ripped up the plywood (there was so much glue it pretty much came up with the hardwood). The plywood was also glued and screwed into the cement.

We’ve gotten most up but are having issues with the remaining glue. There are some spots with wood still stuck to the glue and we cannot get it up! we’ve tried glue gone, scrapping, paint thinner and hot water and these small spots of gluey wood don’t seem to budge! Any suggestions?

A: Bostik does make an adhesive remover that would likely soften it. You could also rent a machine to help chop up the remaining ply and adhesive. It’s a nasty job.

Solvent to soften black rubber carpet underpad?

Q: I am trying to remove a solidified layer of black rubber carpeting underpad from a hardwood floor.

Can you suggest a solvent to soften it? It seems to respond to acetone-based nail polish remover, but I would need gallons.

A: If it responds to acetone, you can buy that in larger quantities at any paint store. However, be aware that the acetone will also remove any varnish or polyurethane that may be under the padding.

Have you tried scraping it off in hardened state with a drywall trowel or scraper?

If it does chip off, the way to go may be to leave it dry and work at it.

Scrubbed a few marks out of the floor with a scrub pad, also scrubbed off the finish

Q: I was cleaning the wood floors in the apartment I moved into this week, and I scrubbed a few marks out of the floor with a scrub pad. I was able to remove the marks, but I also took the finish off the floor in a couple of the spots.

My question is: Is there any type of specific product out there that I could apply to these dull spots, that will make them appear glossy? Or did I just totally mess up these floors? Any advice would be appreciated.

A: I would rub down the entire boards or pieces affected then tape off the same boards. Apply a polyurethane (if that is the finish used) in the sheen of your choice (gloss?) and remove the tape immediately.

Replace over 100 cracked boards or replace whole floor?

Q: In our new home (we have had it for 3 months) the maple floorboards are cracking. Our builder wants to lift and replace only the cracked boards. However, at this stage there are over 100 boards that need replacing, and more are cracking as time goes on. We have installed a dehumidifier in the home as the builder thinks it’s due to too much humidity because we had cupping as well.

My question is, once so many boards are lifted and replaced by gluing in, will they lift and become uneven over time? Will my floors look level in say 4 or 5 years? I have heard that the glued floorboards will eventually not be level and I think the builder should be replacing the entire floor.

A: I will make an assumption that your maple floor is pre-finished and has bevelled edges. You may be surprised to know the reason they have the bevels (eased edges) is because these floors are NOT perfectly flat. The edges help to hide that. If he uses a polyurethane adhesive I would not expect the boards to move or come loose.

I would certainly be concerned about the cupping of the floor. It is definitely connected with excess moisture coming from below the floor. I doubt this is caused just by excess humidity. Has anyone placed a hygrometer on the floor to see what the RH is in the home? What about a moisture meter to take some readings of the wood itself? This is something that should be done before the floor is ever installed. Was the sub floor and the maple checked with a meter before installation began? It is a new house. At some point it was wide open with no roof, no windows, no heat and exposed to the elements. The plywood at some point had to be wet. Was it within 4% moisture content of the moisture in the maple when first installed?

The horse is out of the barn now. I don’t know the square footage of the entire floor area. Over 100 boards needing to be replaced seems like a lot. Sometimes it makes more sense to just start over, but apparently the builder doesn’t feel that is the case.

How are they going to deal with the cupping? The source of the moisture will need to be addressed first. If the basement is open, they may want to put a meter on the plywood to check it’s moisture content. If the floor now shrinks as the heating system comes on you may then be left with a lot of gaps.

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?

Can Pepsi strip off polyuerthane finish?

Q: I put water based polyuerthane on our floor. It looked very good, but when some Pepsi got spilled on it, it striped off the polyuerthane finish. How do I fix this?

A: I’m at a loss as to why Pepsi would cause a floor finish to delaminate from the wood. I’m thinking you may not have abraded the previous coat sufficiently to gain a good bond. The moisture from the spill was able to get under the coating and lift it off the floor. You can try taping off the affected boards and rubbing them down really well with fine sandpaper and coating again. Then remove the tape.

Hickory floor making popping sounds

Q: Our home is 70+ yrs old with original pecan/hickory wood floors. A week ago we had a floor restoration repair company repair and replace a badly rotted area caused by an adjoining bathroom leak many years ago. After cutting a 3′ x 5′ area of flooring and opening they found it rotted through the floor joist and someone previously cut a support beam which was just hanging.

They had to cut the rotted joist out and married a new joist in after supplying a new section of support beam.

They then sealed the hole, installed moisture barrier, new sub-floor, new wood floor boards, stained to match existing, sanded the rest of the floor, restained, sealed all with water base products. The floor is beautiful and you cannot tell anything was done. But for last 3 or 4 days we have heard loud popping from the room, which is empty right now.

Should we be concerned?

A: No, I don’t believe there is anything to worry about. Hickory is rather sensitive to environmental changes and other disturbances which means it expands and contracts a lot. I hope the guys used a sealer under their coating which has some stretch to it. I would keep an eye on that. What along board edges for any signs of cracking. As an example of how most things move, I have a steel roof. You should here the noise it makes on the coldest winter nights. It bangs! Your popping sounds should stop once the floor settles down.

Follow-up: Thank you SOOOOO much! We will keep eye on edges as you said.

Gaps from a puddle left on wood floor

Q: I poured water all over the floor to mop, and I left a huge puddle on the floor. I came back and dried it up and then noticed big gaps between the floor boards and the ends of the boards popping up. How do I get the floor back to normal?

A: Excessive amounts of water is an enemy of most woods. I would set up fans and a dehumidifier and try to dry this floor out. You will likely not be able to do anything but fill the gaps because the floor, under pressure from so much water has swelled, moved the boards. As it dries and shrinks it leaves gaps.

Similar Q: I had just broke my foot and I iced it then I put a plastic bag on. The hardwood of my bedroom I noticed it was wet when I got home from school and it was a little peeling to do you think this is a big problem? What about mold?

A: You don’t have any worries about mold but I imagine the affected boards may either crown or cut. The only thing you can do now is wait and allow time for it to completely dry out.

Gaps the size of a nickel after installation

Q: We installed a 5″ select white, glued and nailed, unfinished oak. The subfloor 11%. The material 10.2% finished with stain and LNL 1500. On installation the floor was tight and now there are visible gaps the size of a nickel. Can this floor be sanded, re-hydrated, and finished? If so, what process would you suggest?

A: The moisture readings, while not outrageously high could have been a percentage or two lower, but the difference between sub floor and oak is okay. If the air is dry you could run a humidifier. It isn’t often I see a floor that is without some small gaps. And the wider the board the greater potential for increased shrinkage.

This is probably not much help, I know. But controlling the environment is one of the few things we can have some control over.

Follow-up Q: Do you think resanding the oak and adding moisture to it by spraying water – similar to popping – will close the gaps? The house does have a humidifier in the heating system. We are desperately trying not to rip this finished product up.

A: Spraying water on the surface doesn’t have a hope of expanding the planks. I don’t think anyone can ever guarantee a wooden floor will stay tight and never get any gaps. NWFA has always held to the view that a gap about as thick as a dime is normal and expected. I would suggest to the home owner they give the floors time to go through a couple of complete seasonal cycles. It’s probably going to expand a bit in the humid summer. If you have a hygrometer set it on the floor for 15 minutes to see what the moisture level in the room is. I know you can’t have humidity up over 45 RH on cold winter days. But if it is down to 30 or less, that will suck the moisture out of everything. Did you give the flooring time in the rooms to get used to the environment?

Follow-up Q: Yes the flooring was in the house for a week. The only issue with waiting is this is a new construction so the house is presently empty. I will be doing RH testing and moisture reading tomorrow.

A: I figured it was new construction. I really don’t like doing those jobs. Other contractors are crawling over each other and everything gets rushed at the end, whether it’s ready or not. Back in the early days of self employment when I had to do sub contract work, there were a lot of jobs in new sub divisions. Installation of Bruce. There was no acclimating the flooring. The last week before closing, every trade was in the place. Every rule and precaution were broken as far as flooring goes. I kept telling the builder, if this floor goes south, it isn’t my fault.

One of the worst I saw was when I lived in Niagara. I got a call to look at a floor in a sub division. It was all badly cupped. Clearly the structure was not dried out before the floor went in, and the wood swelled. The builder told the home owner the floor meets warranty specs. I couldn’t believe it.

Black dots where area rug pad was

Q: We have a house with 60+ year old oak floors. There were 30+ year old area rugs, that had a reddish/brown pad under them. The pads left black dots across the floor. Can these be cleaned/removed or do the floors need to be sanded?

A: You may have a bit of an issue with this. These black dots are probably water stains from the carpet being steam cleaned or shampooed over the years. The moisture telegraphed to the center of the bumps on the underpad, it sounds to me. So, yes the floors will have to be sanded. Hopefully the stains can be removed. If not you would then have to stain the floors to hide the marks. This all hinges, of course, on whether these old floors are thick enough to handle a full sanding. It depends how many times they have been done in the past and how thick they were originally.

Follow-up Q: Thanks for that info Craig. I should have said that the rugs were never cleaned or wet. A rug guy thought that perhaps the rug mat/pad might have had some clay in it? The dots are uniform across the entire rug area, 1 inch apart horizontally and vertically. Some areas the dots are darker, but again it is uniform.

A: Even a tiny bit of moisture over time could do it. Perhaps dampness from beneath, transferring slowly through the floor over the years. The pad was just another layer to slow that moisture down and trap it against the wood. I did a floor years ago which had that pattern on the wood. It wasn’t even dark spots. It was just the outline of the pattern, as if it had been x-rayed into the wood. It was the strangest thing. It didn’t even sand out.

Splits and boards cracking up the middle

Q: I just had 890 sq. feet of A——— Hardwood floor installed in my house. They delivered it and started install the same day. The workers installed all 890 SQ. in two days.

The same night I notice my socks getting caught on some planks. I then saw many boards that began to crack up the middle and along the sides where joined. There are about 65 splits in a hallway that was 100 inches long by 60 inches wide. I design kitchens and the company that installed does our floors.

He said it was cupping due to a manufacturers defect. He basically told me acclimation was a farce. He agreed to replace all and brought wood to sit for 5 days before new install, just to appease me. Well I found out he was using A——— builders hardwood again. Is it due to poor quality?

It’s not done yet, but the hallway has just one board that’s split. He will replace it. The living room has just one split I can see because the cardboard is covering it while they do other rooms. He said splits are expected because it’s natural wood.

Is this acceptable and do I have to live with wood that splits up the grain of the planks? It’s not even finished yet and I afraid to complain. Am I being a nut case or should I stand up for myself? Please Please Please help me.

A: Absolutely stand up for yourself. The splits will get worse when the finish is applied. If this product is a cheaper grade or even mill run, then yes, you will get that type of thing, but they should be picked out and not installed.

I disagree that acclimating is a farce, but the main issue here seems to be poor product. I wouldn’t have that in my floor and you are right to complain. If I was installing this floor, I would be complaining to the people where I bought it.

Similar Q: We had solid white oak flooring installed, B********, and we have had vertical cracking occurring. Do you think this is a defect in manufacturing? What causes this? Any remedy?

A: I’ve seen this in a couple of white oak floors, about 65% rift and 35% quarter sawn, several such boards had crept into the installation. I would think the best thing to do is replace the affected boards.

Brown stains from straight vinegar on bare wood floor

Q: I accidentally mopped a newly stripped hardwood floor with straight vinegar! Now I have
brown stains circling my floor. Tried bleach, I know it’s not good, and it did not work. One of your questioners said she used hydrogen peroxide on stains and it worked but did not accept the stain.

I’m using polyurethane over natural pine floors. What do you think of my mess? I think it will be okay if the stain comes out. I’m probably going to need to try sanding again to remove the vinegar stains.

A: At least you are not facing a chemical we know little about. I would lightly sand the marks and it should come out. Here is a suggestion for staining pine. I have found a great product called Waterlox. It is a Tung oil based penetrating finish. It offers the best way to stain soft woods. Mix 4 parts Waterlox and 1 part stain. Mop on and walk away.

Put oil on wood floor, now it’s tacky

Q: I have put some D***** oil on my wood floors and now they are tacky. What can I do to get rid of the tackiness? I have tried to buff with microfiber cloths, but it doesn’t seem to be working.

A: I think I would wipe it down with mineral spirits.

Related Q: How do I get an oil-based cleaner off my new engineered, dark hardwood floor? Help! It looks so bad!

A: Try a cleaner such as Bona Kemi floor cleaner, or Poloplaz floor cleaner which can be purchased online.

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.

Adhesive for splits breaking off wide pine floors?

Q: My house has wide pine floors and several of them have partially split along the long side, right next to the gap from an adjacent board. I am afraid of one of these splits breaking off completely. I am unsure how best to repair this. I would be happy to send you a photo.

A: Do you have any way to inject some adhesive under this cracked piece?

Follow-up Q: I think I could get something under there. Maybe some clear epoxy. Can you suggest something?

A: I’d like to suggest Gorilla type adhesive except in this case it worries me. It expands as it cures. I’m afraid if this split edge is just hanging on, the adhesive will actually push it up and we will have made the matter worse. If the gap is wide and deep between the boards, you may have to pack something in the gap to prevent the glue from running away. Cyano acrylate (from Lee Valley Tools) sets up in seconds. It would be ideal if the adhesive bottle also came with a long nozzle allowing you to direct the adhesive sideways into the groove on the board. (assuming it is the groove side that has the split). Fast setting with a nozzle, and best to stay away from expanding foam urethane. Some wood glues set in about half an hour. That might work too.

Follow-up: Thanks again. I’ve attached a photo but its a bit difficult to take a picture of. I had read about the gorilla glue and I thought that the expansion might help as the splits go downwards when stepped on but maybe the expansion can’t be reliably predicted or controlled. I have previously tried inserting some wood matchsticks (not the striking end) and some wood glue but I was hoping there might be something better. I’ll look into the the cyano too as you suggested.

Repairing burn marks on floor

Q: I had to belt sand a burned oak floor. In spots I got the stain correct [matching golden oak], now I want to feather the urethane edge. The original floor is 4 coats of urethane I think. The divots were 1/8 deep.

A: I haven’t seen what this burned area looks like but if it was bad enough, I may have opted to replace the damaged boards. In coating, you are better off isolating entire boards involved in the repair. Sand coats of finish on entire boards, remove dust and use painters tape along edges of those boards. Apply a thin coat and remove the tape immediately. Repeat as needed. It’s not likely this will be unnoticeable when dry. It time, with some wear it will look less noticeable.

Follow-up: Thank you for your input. I am 62 and I have worked with much wood and finishing. This task is rare and I have not been able to find anyone who has done a repair like this. I will keep you informed when I get it completed. The floor got burned in spots, 2 spots deep, and the rest splattered they are lucky. The wood grain is too beautiful to remove and replace, as it was laid with care and matches. I belt sanded it down, and I have stained it to match, which I got it 90% on. The edges are what I will work on today, when finished with polyrethane, many coats, I will wet dry the final out, and bring the area up. I may end up just sanding the entire floor.

A: Ha, I’m 62 also. 63 in March. I’ve done lots of patch repairs. The older the existing floor is, the more difficult it is to get a good colour match. Plus sanding out a burn 1/8″ deep? You would have to feather sand out from there much further so it doesn’t look like a trench or trough. I would apply thin coats of finish on just the affected boards as mentioned. Even with this, the sheen of the coating is likely to not be exact. If you get the stain looking real close, perhaps you can just screen the entire floor and coat the whole thing? Do a couple of test areas to make sure there are no contaminants which would reject adhesion. I have been using Poloplaz Primero for quite a few years now. It rolls on beautifully and is as close to a no failure finish I’ve ever used. There Supreme is also very good but doesn’t dry quite as quickly.

Let me know how it turns out. Tricky work for sure.

Similar Q: I hope you can help me out. I have a hardwood floor and a ceramic heater fell over and heated up the floor to the point of slightly darkening the wood. Is there anything I can do short of replacing the darkened area?

A: You could attempt to sand to clean wood first but restrict this to the entire boards affected. If this is a factory finished floor though you are best to change the boards.

Floors wrecked by former tenant using some white substance

Q: I had a tenant living in my home and after they left I went to check the apartment.. there’s a nasty aroma and a white substance poured over all the wooden floors throughout the house. It was purposefully put there and the wood was ruined, and all broken apart. Can you tell me what substances can cause wood to be like that and how to remove it?

A: I don’t know. Could it be some type of acid? You could have a sample tested at a lab.

Solvent which was designed to remove glue also softened the finish

Q: I removed the carpet and pad from a hardwood floor, but there was carpet glue all over it. I purchased a solvent which was designed to remove the glue but it also softened the finish in some places and made it tacky. What can I do to fix those spots? Can I put a coat of finish over them?

A: I would give the stairs a good rub down with some fine sand paper and apply a thin coat of finish.

Small indentations in the finish

Q: We recently installed some hardwood floors out of old gym boards. We glued/screwed and plugged them. After banging them up to give them a beaten look, they were stained and finished.

We love the look, but recently found that a folding chair left in place for the weekend has left about 40-50 small crescent moon indentations in the finish for each leg in about a 10 inch radius circle. Some of them are even deep enough to depress the wood. What is the best way to repair this sort of problem? Can I give it a light scuffing of a sanding and then re-apply another coat of finish?

I’m not overly worried about the dents in the wood as the floor has already been distressed, it’s the obvious indentations in the finish that catch the light at the right angle that make it look awful. Any guidance is appreciated. Thanks.

A: I don’t think there is any way to hide these dents short of sanding/scraping them out and staining, finishing the area again. You could try filling them with wood filler, staining them and applying more finish. The lower the shine level in the coating the better is the ability of the finish to hide defects.

Follow-up Q: Thanks. Unfortunately I was hoping to avoid having to re-stain the wood. The majority of the dents are relatively shallow, I’m pretty sure that most don’t go through to the wood and are only on the finish. Do you think it would be worth just trying a light sanding and re-finishing first and if that bombs then to re-stain? Or would that just be a waste of time and money?

A: You could certainly try a light sanding of the area. It is the least intrusive approach. You could tape of the entire boards of the affected area, buff and coat just those boards and then remove the tape. It’s worth a try.