My wife Lauren and I have been renting from her parents for the last year, and currently live in the house where she spent the majority of her teenage years. It’s been a good setup for us. They are giving us an incredible deal, which has allowed us to live in a part of town where Lauren feels safe. You see, Lauren was diagnosed with bipolar disorder several years ago, and the feeling of safety (and lack of triggers for paranoia) are a big deal for her.

After pulling up the carpet, I found that portions of the original MDF particle board underneath were swollen from cat pee from long ago. It was horridly disgusting.
Unfortunately, when Lauren’s family lived here, there was a cat. Who peed. A lot.
I noticed the stench from day one, and it was awful. Before moving in, I rented a carpet cleaner from Home Depot, used a lot of baking soda, and did everything I could to clean the floors. That helped some, but the stench was still there. We had a heavy-duty air purifier going 24×7 which also helped, but it still wasn’t enough. I complained about it almost constantly, but it didn’t seem to bother Lauren. Until….
A few months ago, Lauren’s naturopath told us about the toxic effects that cat pee, in particular, can be to humans – and especially to babies crawling around.
At the time, Lauren and I weren’t pregnant nor were we thinking about having kids in the immediate future, but this was a wake-up call, and we finally decided to talk to her parents about having the upstairs refloored.
Without thinking about the work involved too much or the implications, Lauren and I offered for me to do the work. Huge mistake! As anyone who has done home renovations or remodeling projects knows, the amount of time that you think a project will take is never accurate – and the time commitment winds up being a lot more (and the project often times becomes a lot more complicated along the way).
Just about anything that could go wrong, did go wrong. I had hardly any experience with this type of work either.
As of this blog post, though, the project is nearing completion, I have had friends, my brother (who was once a general contractor), and Lauren’s dad help me on multiple occasions, and I’ve learned quite a bit about redoing floors (including floor joists and frames), drywall, tiling, and more.

A section of the hall, where the cat peed on the wall. I took up some of the flooring too, to be sure I got it all.
Without further ado, here are some of the valuable lessons I’ve learned along the way:
- If cat pee smells even before you start to take up carpet, it’s going to be a lot worse once the carpet is up.
- Vinegar is supposed to help neutralize cat odor. If there’s a lot of pee, though, don’t waste your time. Tear all of the affected parts of the floor and drywall out. Nothing will get rid of the stench.
- No, really, tear everything out. ESPECIALLY if it got onto the drywall. You see, drywall can’t really get wet. If it does, it just absorbs the moisture (think: cat pee. And the integrity – strength, if you will – will decrease).
- Carpenters who originally put down MDF particle board on top of plywood should be defenestrated. They saved maybe a few cents per square feet – but that’s not the proper way to lay subfloor. Also, MDF particle board absorbs liquids too (and swells up. See points #2 and #3).
- Cats sometimes spray their pee vertically (supposedly to mark their territory). When this is done to drywall, over several years, it is disgusting.
- I now know how to replace drywall.
- I know what thickness plywood used for subflooring should be (it’s 3/4 inch, by the way)
- Do not, under any circumstance, cut out (or allow your friends with carpentry experience to cut out) the bathroom floor without actual evidence of a leak or other problem.
- My friend, who meant well, cut out the floor of an entire bathroom, because he wanted to make sure that everything was “fine” underneath. It was. But that also added a significant amount of work to the project, as I had to install new floor joists along the edge of where the cuts were made, to support the new flooring that I would eventually put in.
- I now know how to install floor joists
- Last, but certainly not least: to be able to live in a house without the smell of cat pee is a wonderful thing indeed.
- Bonus: Don’t volunteer to refloor a house that you don’t own without fully knowing what you’re getting into. (Special thanks, though, to my father-in-law who has come out several weekends to help me on this project, and who temporarily reduced my rent to help account for all of the time I was spending on the project).

New floor joists that I installed into the bathroom. Interestingly, there were not supports originally underneath the toilet. I put some in!
As annoying as this project has been, and as much work as I’ve put into this project without a whole lot in return, I can safely say that I am a much more experienced carpenter now, and many of the skills that I self-taught myself along the way will be invaluable to me for the rest of my life.