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How to Get Rid of Cat Urine Smells in a Basement

Chelsie Frasier

By Chelsie Frasier

cat pee at the carpet

There’s nothing worse than the foul smell of cat urine in your basement. No matter how much you scrub and clean, the smell just doesn’t seem to go away. There are ways to get rid of this odor in your concrete floor, as well as ways to seal the floor to block any odors that you can’t get out.

Removing cat urine odors in concrete is a two-stage process. For areas with heavy odors, an additional stage may be required. If there’s no drain in your basement, it will help to have a wet vac available to draw bacteria out of the concrete. If you’re in a pinch, you can also use a carpet cleaner for vacuuming up liquid.

Normal Cleaning Won’t Remove Urine Odors

cleaning floor carpet with spray rubber gloves
Image credit: Syda Productions, Shutterstock

You may have tried traditional cleaning methods to remove the smell of cat urine to no avail. The stains may be gone, but the smell remains no matter how hard you try.

Concrete is essentially a sponge. It’s porous, so if a liquid is allowed to sit on it for a period of time, it gets absorbed. This is why it’s so hard to get stains and smells out of concrete floors.

Urine contains uric acid crystals that bond to the concrete when the urine dries. Unfortunately, the crystals work their way deep into the pores of the concrete. The longer the urine is left to soak into the floor, the deeper it soaks in.

The problem is that uric acid crystals (which are causing the smell) are insoluble. They don’t bind to regular cleaning solutions or soaps, so they stay in the concrete regardless of how long you’ve scrubbed. While the smell may temporarily dissipate, it comes back stronger than ever any time moisture is introduced. Basements are particularly susceptible to this because they are underground, meaning the concrete is constantly exposed to moisture.

When moisture or humidity is introduced, the uric acid crystals release a gas, which is the cat urine odor that you smell. The best way to stop this from happening is to use an enzymatic cleaner designed to break down and attack uric acid crystals.

Steps to Remove Cat Urine Odors From Concrete

woman cleaning the floor
Image Credit: VGstockstudio, shutterstock
  • Use a blacklight or UV light to determine where the urine is located in the concrete.
  • Clean affected areas with an antibacterial cleaner, like TSP, to remove any bacteria.
  • Let the concrete dry fully.
  • Treat affected areas with an enzymatic pet odor remover.

Clean Cat Urine Stains With TSP (Tri-Sodium Phosphate)

What you need:

  • TSP
  • Bucket
  • Hot water
  • Rubber gloves
  • Goggles or another form of eye protection
  • Bristled brush or deck brush
  • Wet vac or carpet cleaner

In addition to removing the smell, cat urine should be cleaned up to remove any bacteria or parasites that might be lingering. Enzymatic cleaners are great for removing the smell, but they don’t remove bacteria.

Once you know where the urine stains are, scrub the area with a strong solution of ½ cup of tri-sodium phosphate (TSP) and 1 gallon of hot water. Since this is a strong concentration, be sure to wear gloves and eye protection while cleaning. Pour the solution on the affected area, and scrub with a nylon-bristled brush, like a deck brush. Let the TSP solution soak into the concrete for at least 10 minutes.

Once the concrete has absorbed the TSP, you can rinse with hot water and vacuum up all the remaining liquid with a wet vac or carpet cleaner. Run over the area with the vacuum at least twice to make sure you get it all.

The reason for using TSP is that it removes the stain, any remnant bacteria, and any other residue left behind in cat urine. Once you have completed cleaning with TSP, the only thing left behind will be uric acid crystals, which you can clean up using enzymatic pet odor removal.

foor cleaning
Image Credit: Lucy Lulu, Shutterstock

Applying Enzymatic Cleaner to Concrete

What you need:

  • Liquid enzymatic cleaner

Enzymatic cleaners work by using non-harmful bacteria to digest odors, stains, and waste. The bacteria in the cleaner breaks down small molecules of uric acid crystals into even smaller bits. The bacteria then digest the bits and break them down into carbon dioxide and water.

Enzymatic cleaners are available in powder form and liquid form. Since you’re working with concrete rather than carpet, using one available in liquid form will be better than a powder or spray.

Do note that enzymatic cleaners need air exchange in order to work. Since concrete absorbs uric acid crystals deep into the floor, it will take more time for the cleaner to work than it would if you were working with a non-porous surface. Particularly bad smells may require multiple treatments to fully get rid of. Occasionally, you will have to let the enzymatic cleaner soak into the concrete for days or even weeks.

Sealing Concrete From Cat Urine Odors

In certain instances, you may have to seal the odor into your concrete to prevent it from working its way back to the surface. Even if you have removed the urine odor, this step will prevent further odors from creeping up.

The only type of sealer that works on cat urine odors is garage floor coating. It is film-forming and doesn’t breathe. Any sealer that enables your concrete to breathe will allow odor to escape, such as acrylic and penetrating sealers.

Applying garage floor coating is a complicated process that requires grinding or acid etching your concrete before application. Once the coating is applied, however, no cat urine odors will be able to escape the concrete.


Feature Image Credit: Pixel-Shot, Shutterstock

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