Cat pee stains.

[Jan Smith]

Hello,
I hope this is the right place and if not please move it.
I am dealing with task of removing soaked cat urine from hardwood flooring,
so far I tried the hydrogen peroxide method over the last couple of days but very little success so far.
Any tips on how to tackle this before bringing out the sander?
Thank you.

[Paul F Franklin]

Is the problem color staining or odor or both? I assume the flooring is finished; do you know what type of finish is on it?

[Jan Smith]

The stains are the issue, the floor is finished red oak flooring but I am not sure what they used as a finish.
423340

[Mark Daily]

I’ve seen a number of online articles using vinegar instead of peroxide but that is for odor. I don’t know if it will remove the stains but it’s worth a try.

[Jan Smith]

I’ve seen a number of online articles using vinegar instead of peroxide but that is for odor. I don’t know if it will remove the stains but it’s worth a try.
That is worth a try, would bleach be also an option?

Thank you.

[Phil Rose]

My perwonal experience has been with floors under carpet, but in case it helps, here was the process. After removing the carpet, the floor was doused with at least two applications of Nature's Miracle. Expensive but did the trick. We then sealed it all with Polyurethane and recarpeted. I know you cant follow that with beautiful finished flooring, but i would try the Natures Miracle first. The concern is the urine that gets into wood - side and bottom of the nice wood on top, and into the subfloor.

[Jan Smith]

Good call Phil, that reminded me that I have Nature's Miracle leftover from another job somewhere hiding in the shop.
I will try that tomorrow.

[Ellen Benkin]

When I bought my house (30 years ago) the oak hardwood was stained with dog urine. NOTHING took out the stains. I tried all the chemicals available at the time. Sorry about that.

[Tom M King]

You can't get the stain out. That's no joke, and not idle speculation. You can not get that stain out.

New pieces will have to be put in. This from first hand experience in my first, and last, house flipping venture. I bought the house cheap, because others had tried, and made good money on it, but it's not something I wanted to do again. I both replaced parts of the floor, and inlaid 1/4" pieces in some of the smaller spots. If I had known how much was involved when I started, I would have just ripped the whole floor out, and replaced it.

[Nathan Johnson]

That is worth a try, would bleach be also an option?

Thank you.


Do NOT use bleach. When the bleach mixes with the ammonia in the cat urine, it creates extremely toxic vapor.
I made this mistake trying to clean cat urine from a cement slab after removing carpet in our lower level and nearly ended up in the hospital. I’ve never been that sick or vomited that violently before or since.

I've had some success with vinegar on cat urine odor, but the very best I've found is called Anti Icky Poo.

[Rick Potter]

Way back in the 60's I worked as a carpet cleaner/installer. It was really common back then to put wall to wall carpet down on top of wood floors because of animal stains, and I both used, and talked to many owners who had used, everything trying to get the stains out.

Not gonna happen.

[John TenEyck]

I think you can get the stain out. The tannins in the wood have reacted with the cat pee and turned black. Oxalic acid should remove that. After you have neutralized the cat odor with Nature's Miracle, apply a mix of oxalic acid in really warm water. Wear an activated charcoal respirator both mixing and using it indoors, and eye protection too. You can make it like a soupy paste so it doesn't run all over the place. It might take several applications to remove it all, or it might not remove it at all, but for $5 and a little of your time it's worth a try before ripping out and replacing the wood.

John

[Tom M King]

Oxalic acid will only lighten it the slightest bit. Wood Bleach about the same. You can't sand it out either. Been there.....

Here is a picture of the worst room. We replaced all of this. There were Many more smaller places in other rooms. The house sold for the land cost. Pro floor finishers had redone all the floors, and the house had been shown over 100 times. This room was after we sanded it.

[Lee Schierer]

The stains resemble iron stains on oak. You might want to try https://www.finewoodworking.com/2018/10/10/remove-iron-stains-wood

Before you cut up the floor. You might need to remove the floor finish first to reach the staining.

[Tom M King]

It's much different than iron stain. Find pro floor finishing forums, and see what they have to say about pet stains. You can't get them out. You can't stain over them with the darkest stain known to man, and hide them.

[Jan Smith]

Thanks for the replies, I will talk to the owner tomorrow and see if she wants to do the method Lee posted.

[Tom M King]

Please post the results, with pictures.

[Jan Smith]

It's much different than iron stain. Find pro floor finishing forums, and see what they have to say about pet stains. You can't get them out. You can't stain over them with the darkest stain known to man, and hide them.
Maybe I should get a tape with hardwood flooring printed on it.:p

[Jan Smith]

Oxalic acid will only lighten it the slightest bit. Wood Bleach about the same. You can't sand it out either. Been there.....

Here is a picture of the worst room. We replaced all of this. There were Many more smaller places in other rooms. The house sold for the land cost. Pro floor finishers had redone all the floors, and the house had been shown over 100 times. This room was after we sanded it.
Wow, fortunately for me we are only talking about a small area, I will tell my customer.

Thank you.

[Tom M King]

Here's how I did the smaller areas. First a router hogged out most of the area, and then trimmed up with a chisel. The end joints don't have to be at the same place as the flooring that's down. Just stagger any new end joints.

This was to let in 1/4" pieces. West Systems epoxy was used to glue the inlays down. After we did all the small areas like that, the whole floor was sanded, and refinished with a natural, clear finish. No one could find the repaired spots.

[Tom M King]

To let in a new piece next to a baseboard, make a gauge so you can get the new piece to finish close to where you want the top surface, so you don't have to do a lot of cutting down of the inlaid piece, since you can't give a router good support all around.

You will find more theorists on internet forums, than you will find people who have actually done something.

http://historic-house-restoration.com/images/gaugingproperlevel.JPG

[Mark Daily]

Maybe I should get a tape with hardwood flooring printed on it.:p
Or maybe you can faux paint it to match! Lol:)

[Jan Smith]

Talked to the customer and I told her what I learned here and she wants to try the barkeepers helper method.
I will take pictures of the process.

Thank you.

[Jan Smith]

So far it goes as most here have predicted.
This is stain one after several days of 3% hydro peroxide and one day of barkeepers helper.
No real change as far as I can tell.
https://sawmillcreek.org/attachment.php?attachmentid=423566&d=1578877340Look almost like Wu-Tang Clang was in da houz.
https://sawmillcreek.org/attachment.php?attachmentid=423567&d=1578877361
Sanded the finish off and now its covered with barkeepers helper again plus a rag to keep it moist overnight and if this does not show any improvement by tomorrow I will just refinish it.

2. Stain which is worse.
After several days of 3% hydro peroxide and one night of soaking in of Nature’s Miracle which also more or less did nothing.
https://sawmillcreek.org/attachment.php?attachmentid=423563&d=1578877239

https://sawmillcreek.org/attachment.php?attachmentid=423564&d=1578877289
Now also covered with a healthy does of the barkeepers helper.

Good thing is that the customer is fine if it is a lost cause, she just wanted me to give it a try.

[John TenEyck]

Barkeepers Helper has a low percentage of oxalic acid. It didn't do much for me to remove an iron stain from oak. Pure oxalic acid took it out completely. You should be able to buy it at your local ACE Hardware.

John

[Mel Fulks]

Or maybe you can faux paint it to match! Lol:)

I was just checking to see if that had been suggested. We are wood workers with a number of skills. It's likely that only
a few of us have that one. But I think it is the right one for the problem. It's a perfectly good fix used in "the finest museum houses of our finest patriots". I would attempt it ,...to show my wife ...I can't do it. Then hire someone who does
faux finishes.

[Jan Smith]

https://sawmillcreek.org/attachment.php?attachmentid=423716&d=1579039671

https://sawmillcreek.org/attachment.php?attachmentid=423717&d=1579039690

No real change after two days with Barkeepers Helper.

So while I am at it I will try the pure oxalic acid John recommends.

If that does not work I hope all the different remedies soaked together in the wood will do the trick.😛

[John TenEyck]

Is the finish sanded off on the stained areas? For any liquid treatment to work it has to go onto the bare wood.

John

[Tom M King]

Like I said earlier, been there, tried that, didn't work.

Thanks for posting the pictures, Jan.

[Tom M King]

When I epoxied in the inlays, I first sealed all the edges, since I wasn't sure if penetrating epoxy might be visible after sanding the floor.

For a sealer, I used Bona Naturale. It's an industrial floor finish that, on Oak, you have to examine closely to even tell that anything is on the wood. It will change Pine a little, but not Oak. I used it for the first coat on the floor, and final coats were Bona Traffic HD.

I guess if you only sand small areas, being careful to stop on board edges, you may be able to only finish the repaired areas. Scraping will probably work better than sanding, to stay on a board edge.

The Naturale is only sold in gallons, and the last I bought was something like $115, so you will probably want to use something else to pre-seal the edges.

On that flip house, I burned probably $8000 worth of time trying to find something that would get rid of the stains, with no luck. I tried all the common things, and several others that probably hadn't been tried before. That picture of the room was after sanding, and all sorts of chemical tries. If I had known what to do to start with, I could have saved a week, and a half of time that was wasted.

[Jan Smith]

Is the finish sanded off on the stained areas? For any liquid treatment to work it has to go onto the bare wood.

John
Yes, the finish is sanded off.

[Jan Smith]

@Tom M King, yeah and I would have left it after what you and others said here but it was worth a try to my customer
and after I will have tried oxalic acid I will seal it up no matter what with minwax oil modified poly since that is what I have at hand.

[carey mitchell]

Hydrogen peroxide works - but the drug store stuff, 3%, won't do it. I have had great success with 30%, diluted to 15% with water. You will need to get this from a chemical company. Here are a couple of sources:

https://www.amazon.com/Stabilized-Crystal-Liquid-Peroxide-HC-50409/dp/B00TP1IZDE/ref=sr_1_16?hvadid=3527441749&hvbmt=be&hvdev=c&hvqmt=e&keywords=30+hydrogen+peroxide&qid=1579478927&sr=8-16

https://www.amazon.com/W-Bionics-Percent-Hydrogen-Peroxide/dp/B00016R37Q/ref=sr_1_8?hvadid=3527441749&hvbmt=be&hvdev=c&hvqmt=e&keywords=30+hydrogen+peroxide&qid=1579478841&sr=8-8

Note that the "40 volume" is 12% concentration.

When my son purchased a town house with cat pee everywhere downstairs, it was so strong it made our eyes water (he wondered why the heavy smell of air fresheners when he lloked at it). We removed the carpet and pad (ugh!) and the tack strip was rotted! The concrete slab was saturated. I went by a chemical company that we did business with and picked up 2 gallons of 30%. Diluted to 15% with water and applied with a garden sprayer; it fizzed and bubbled like crazy. Kept applying until fizzing ceased. We left for lunch and upon return, we could smell the carpet on the curb a block away (bet the neighbors loved that) !! Inside, there was no odor at all.

All that said, 30% H2O2 is not to be taken lightly. GOOD rubber gloves, eye protection and at least a dust mask to avoid inhaling the mist are essential. If you get it on your skin (I have some right now, from dealing with an antique dresser with the usual odor) it causes the skin to turn white and sting. This lasts about 1/2 hour and returns to normal. Would not want to try it in the eyes.

[Tom M King]

This was not about odor. It was about stain in Oak flooring.

[Jan Smith]

Both pics are taken after being treated with 10% hydrogen peroxide for a few days with no real effect on the stains.
The floor boards will be removed now.

https://sawmillcreek.org/attachment.php?attachmentid=424300&d=1579739417
https://sawmillcreek.org/attachment.php?attachmentid=424301&d=1579739449

[John TenEyck]

Did you ever try the pure oxalic acid?

John

[Jan Smith]

Did you ever try the pure oxalic acid?

John

No, I was thinking about that but since all I tried did not do anything as some members here correctly predicted tearing out the effected strips is the next step.

[Jan Smith]

To finish this up here are the pics of the fix.
https://sawmillcreek.org/attachment.php?attachmentid=426051&d=1581876178
https://sawmillcreek.org/attachment.php?attachmentid=426050&d=1581876159
Thank you for all the help and next time I know.

[John TenEyck]

That turned out very well. Nice work.

John