Let's talk about... Cat Piss

I love my cats, but damn they’re messy. Food thrown all over the floor, scratching, hairball vomiting, fleas, etc. Our current dilemma is “How the hell do you clean cat piss out of brick?”

We have two cats, both female and neutered, so thankfully the stench isn’t as rank as it could be, but it’s persistent. Typically they’re house trained, but at some unknown point they took to sneaking into an unused fireplace and using the brick surface there, where the mess has soaked in and dried.

I’ve vacuumed the fireplace, mopped it, and repeatedly soaked it in a spray specifically meant to get rid of the odor. It’s better than it was, but the piss-smell yet lingers, especially around 6am when my wife goes to work for some unclear reason.

So, any ideas how me might fix this, short of ripping out the fireplace?


Oh, this is about LITERAL cat piss, not METAPHORICAL cat piss.

Carry on.

The strong smell of cat urine comes from the high level of ammonia in it. Mixing that with bleach may not be advised.

I’ve tried a lot of these products (seriously–a lot), and in my experience, the only one that works worth a damn is Nature’s Miracle. Get the basic “for cats” formula (linked). The other formulations don’t work as well. You need to soak the surface with NM, scrub it and wipe it dry, and then soak it again and leave it wet. When all of the NM has evaporated and the surface is dry again, check for smell. It may take a couple of applications, especially if the smell has been there for a while. Only use the Nature’s Miracle–don’t clean it with soap or anything first, as this can sometimes make the smell harder to get out.

Here’s a thought.

Unused fireplace.

Can you use it? (Does it have a flu, if so, make sure you check the damn thing to be sure it’s open or suffer the consequences!).

Figure out how to have a very hot burning fire.

I dunno for sure, but it would seem like it would work on heating up the brick to the point where the remaining molecules of cat piss and stench are either evaporated, burned off, etc. Perhaps the smell of the burning wood from using the fireplace would also permeate the brick area and I figure that’s a better odor than what you have now.

If it’s a working fireplace you really have nothing to lose by building a few hot fires and seeing if that does the trick.

Bleach again. Bleach + cat urine creates chlorine though, so be … careful. Honestly. A big pool of urine plus straight bleach is going to create quite a choking cloud of the stuff, eye wateringly concentrated. But bleach does work very, very well. It’s also satisfying to see through the chemical reaction the components of urine being “identified” and “neutralized”.

There’s not enough actual ammonia present unless you’re talking about liters of cat piss. Just leave a window open and everything is fine. The other option would be denatured alcohol, douse the brick with it, let it soak in, apply another dousing and light it on fire.

My assistant @ work almost killed herself cleaning her stove. She was using a solution of bleach and ammonia.

For us non-chemists, I’m not sure we fully understand the idea that it’s not ok to start mixing things together like in Breaking Bad.

Luckily her son found her passed out and called 911, but she did some serious damage to her lungs that affects her years later.

So, do be careful, all I’m sayin’.

On account of being very, very far away, I’m going to recommend the soak in alcohol and light on fire method. I’m sure there’s nothing that could go wrong.

I’ve been holding off on nuking it with Bleach, as the ammonia made me hesitant and I wasn’t really sure what would happen. I’m saving that for a last resort.

Thanks for the “Nature’s Miracle” suggestion Ben, I’ll give that a shot. Difficult to scrub much though as it’s soaked into cracks in the brick. :-(

The “Burn it!” option is intriguing, but I’m reluctant to follow through as the fireplace isn’t well designed nor in a good place and it’d be a mess to cleanup itself. I’ll keep it in mind though, as one further last resort after bleach.

Thanks guys!

Zorbx. It works.

If burning the fireplace doesn’t work, burning the cats is always an option.

Also, if the cats keep doing this, consider lighting them on fire at the same time when nobody is looking.

Damnit Mightynute, apparently we were having the same thought at the same time (you are winning).

I’m not sure whether Mightynute’s previous profession makes me more or less inclined to follow through on the “Alcohol + Match” fix…


Clearly, the answer is to move.

I only blew myself up the once. And I don’t recommend C4 as a home cleaning method. Although it’s pretty much guaranteed to sterilize the area.

My father insists that a solution of baking soda and water plus vigorous scrubbing should neutralize any odors. Then again, I think according to him, baking soda and water also neutralizes arthritis, gout, and communism.

Trick question. Cat piss is simply the most permanent smell on earth. Utterly impossible to get rid of completely. We discovered where our cats pissed in the far corner of our downstairs. Ripped out the carpeting (disgusting anyways, but that’s another story) and replaced with tile. I can still smell it to this day. We have not had cats in 7 years.

More seriously, definitely try Nature’s Miracle. I assumed that’s what you meant when you mentioned a product specifically designed for cat smells, but if you weren’t, you really should. It’s the best pet-odor killer on the market by far.