Remove Various Stains and Smells From Wood Floors

Stains and spots compromise the beauty of your wood floors. If your floors have blemishes from things such as pet urine, coffee, blood, ink, latex paint or chewing gum, this eBook is a must read. You will learn how to remove stains without doing the difficult and intimadating carpentry involved in a floor wood repair.

Each stain is unique and affects the wood finish differently. A stain needs to be treated with the proper wood bleach, applicator and sandpaper. This step-by-step guide explains the difference between the three types of wood bleach and how to prepare your bleach solution. In this eBook, you will get to know about the various stain types. You will learn the techniques required to remove stains that are embedded in your floor finish.

This eBook was written for those people who don’t mind puttering around touching up a floor finish. As long as you follow my directions closely, you will see how easy it actually is to remove a stain. Besides, if you have an old floor that is stained, it is worth the read to learn how removing those ugly spots will bring back your gorgeous floor!

The most common question I am asked is how to I remove dark urine stains from hardwood floors. Read this and you’ll find out how do this and take care of other accidental spills on your floors. I think I’ve covered it all in this article.

Most of the floor stains people are concerned about are pet urine. It seems that when we bring our pets in from the cold, we cannot convince them that the floor is now NOT their toilet. But you MUST convince them of this or your lovely hardwood floors will be a stinky and stained mess.

Coffee, juice and ink will also penetrate the wood finish if left for hours, and in some cases, stain the wood itself. But before you go ahead and read this, you should find out if the stain is just on the surface of the floor finish. A quick read of my floor maintenance articles (it’s free) in this site will show you the safe way to clean your particular floor’s finish. You may be lucky and find that a spot cleaning with a good pH neutral cleaner is all that is need to remove the stain. But, if you find that your floor finish is so unsound that it gets stained with least provocation, it may be best to sand and refinish the entire floor and take care of the stains at the same time.



If you find that it is only the floor finish itself has been stained you can use an extra fine nylon rubbing pad to assist in removing enough finish to get the mark out. Some solvents like mineral spirits will remove some crayon marks or black heel marks if the water based cleaner won’t work. Lacquer thinner will remove nail polish but it will in some cases remove the floor finish too. Blot the spill with a white rag and small amounts of lacquer thinner in this case. There are products like Goof-Off that will remove latex paint splatters, and some old adhesives. And the trick to removing gum off floors is to chill it with a special spray product, so that it will chip off. For deeper stains in the finish you can even remove some more of the stained floor finish with fine 120 grit sandpaper. In a lot of these cases you will have to touch up the finish. So be sure to read the second part of my floor maintenance article to determine just what this floor finish is, so the touch up will blend well. But if you find that the stain is well into the wood itself, read on, I will describe the 3 kinds of wood bleaches and their best applications.

How you remove or rather “bleach out” the stain that you find deep in the wood depends on what caused the stain in the first place.

There are three different kinds of wood bleach and they each act on different stains. For all these bleaches you will need to remove all the finish from the wood surface, either by sanding or chemical stripping. You can read about chemically stripping wood floors also in this web site.

While you are sanding the finish off, this will give you a chance to see how deep the stain is. If you are really lucky you can sand enough wood off so that most if not all of the stain out. Use 80 grit sandpaper, and finish with 100-120 grit. I will usually use a wood scraper for the initial removal, but will always finish up with hand sanding anyway. But you will have to learn how to sharpen a scraper to razor fineness before you use it on your smooth floor. That’s another subject for another time. Use sandpaper if you cannot sharpen a wood scraper well. Hand sanding just takes a little more time, but does the same job.

Most importantly, if you are in the process of sanding the entire floor, you must complete all your sanding down to the finest grit. Then carefully work on the stained areas. If you try to further sand the floor after the bleaching, this may remove enough wood to take the bleached effect out. That’s because bleaching doesn’t really remove the stain, it simply changes the dark discolored wood, to an off white. The bleached areas will however survive a 100 grit screening of the floor as the final step before applying the floor finish.

The first wood bleach is oxalic acid, in liquid or crystal form. This will remove most water and iron rust stains. Apply a strong solution and wait several hours or overnight if needed. Wash off wood surface with lots of water, with a bit of baking soda to neutralize the acid. A lot of deck brighteners have oxalic acid in them. But I like to buy my oxalic acid in it’s pure crystal. In this dry form, it’s highly toxic, that’s why it’s getting harder to obtain these days. Make sure you don’t inhale any of the dry dusty residue on the floor. That’s why you have to wash it off quite well, before you fine sand that spot again.

The next bleach to try is a chlorine bleach. This will remove most dye stains, caused by grape juice, blood or coffee and tea spills. The weakest form of this bleach is regular laundry bleach. It’s worth a try , but it may be ineffective. Better to use swimming pool bleach, called Shock Treatment (dry calcium or sodium hypochlorite). Mix the crystals with hot water, until solution is saturated. Apply to the spot and it should work right away, but try twice if needed and wait overnight. Neutralize the bleached area with vinegar, so it doesn’t ooze chlorine droplets after the wood is finished. Wash it all off with lots of distilled water and let the wood again dry overnight, before refinishing, if it did work. Sometimes even this bleach will take too much color out of the wood, and you will need to replace some of the wood’s tone with a light wood stain, before you replace the finish.

And lastly for organic stains, like urine and feces, your only hope is to use hydrogen peroxide and sodium hydroxide, in a very strong and dangerous concentration ( 27% ). Klean-Srtip is one of these products that’s readily available in North America, and comes with good instructions. Visit their web site at for info on how to use this stuff. You generally have to mix the two parts of these bleaches together, but this contains it own neutralizer, so only a washing up with water may be needed after. Click on the product button at the Klean-Strip site, then the wood bleach link. This last type of bleach will always turn the dark spots to an off white color, which you will then have to blend in with a light colored wood stain to match the color of your finished wood floor.

Incidentally this last bleach is the method we used to use when we wanted a snowy white floor. I used to install a prime grade of maple and bleach any remaining color out of it, and then apply a clear lacquer floor finish. But there are better ways to achieve this effect using a ring porous wood like oak, and white pigment staining it instead. Read more about this in my floor staining article. There is some concern that this type of strong wood bleach weakens and softens the wood surface just a bit. So never bleach the whole floor, just the dark affected areas.

And for really severely urine stained floors you may have to use a darkly colored pigmented wiping stain to color the whole floor, after the bleaching. This may still not blend in very well, but it will look better that no stain treatment at all. Don’t be tempted to skip the bleaching in this case and just pigment stain only, the dark spots will be even more visible unless they are bleached out first. Be sure to read my articles on the sanding and then staining of a wood floor. It is a really very complex job, if you wish an even color, and smooth finish.

All these bleaches are water based, so they will raise the grain and make the wood rough. Be sure to let the wet wood dry overnight. And do be careful when you sand it smooth the next day, so as not to sand out the bleached effect. Do the final sanding with just a little pressure and use 120 grit sandpaper, just until the wood is smooth. Or go over the whole floor gently with a 100 grit screen on a floor buffer, keeping the handle low, to ease the pressure.

The smell that goes along with urine and feces stains could be eliminated first or later, and for that I will refer you to the good folks at the Cleaning center at Don Aslett has written a good book about this very odoriferous subject, called Pet Cleanup Made Easy. You may find you have to use their odor treatments (their X-O treatment works miracles) before and after the bleaching. The odor may be coming from under the floor, on the baseboard and even on or in the wall in some cases.

In the most extreme cases of urine soaked hardwood, we have had to remove the entire hardwood floor and then apply a stain killer paint to the top and bottom (if you have access from below) of the subfloor. Then we laid down a 15 pound roof felt and installed a new hardwood floor. Allowing several days to a week between these tasks helps the odors dry up, and the shellac paint to cure.

This is much the same process I personally had to do when someone died in a room and bled for 20 hours into the hardwood, and softwood subfloor. I had to get this room completely odor free. In this morbid case I removed all of the old hardwood floor. I also had to remove part of the pine subfloor that was blood stained and replaced it with plywood. In addition I painted the floor joists and the top of the ceiling between the joists with the shellac paint before I replaced the subfloor. And then of course I had to install a new hardwood floor. All in all an expensive contract for one small room. I hope you are not tackling such a grim task, but we floor guys are here to fix any wood floor damage, no matter what the cause.

The alternative to bleaching out stains is to repair them out. Click on the wood floor repair article (it’s free). This is a must read before you begin bleaching the wood. You may find that if you have the basic carpentry skills, a wood floor repair of the stained area suits you better. This is what most professional do, as we charge by the hour for repairs. We cannot always experiment with wood bleaches on our client’s floors. We must have a certain and predictable time to completion. And in our case removal and repairs are often the quickest way to go, but not always the cheapest.

I really wrote this article for those who are intimidated by the carpentry involved in floor repair, but wouldn’t mind puttering around touching up a floor finish. I can and will do any floor treatment as a professional floor mechanic. But a lot of times I will simply coach a client through the bleaching process and come back later to finish the floors.

Just remember bleaching doesn’t remove the stain, it just changes it color. You will, in most cases have to re-color the wood with a wood stain, before you apply a floor finish. If you have sanded the entire floor down to the bare wood, and then bleached some areas, you can determine what the final color of the bare wood will be by splashing some mineral spirits on nearby boards. Mineral spirits (paint thinner) will show the color of a clear finish, but will dry up without raising the grain. Good luck, it’s a tricky job, but well worth it to save an old floor.