We had an elderly cat with kidney issues who would sometimes pee in the floor registers. House has one level with a basement.

Sadly he has passed on, but now at least we can clean things up without worrying about any more pee.

There's only about six inches of slope in the ducts underneath the registers, at which point the pee would hit the seam or a nail hole and drip out, so thankfully we don't need to clean long stretches of horizontal duct, just the short bit of duct immediately under each register.

enter image description here

What is a good way to do this? The basement is not finished so we have direct access to the ductwork. I don't think we can easily remove just the angled part, it's nailed to the surrounding subfloor at the top.

  • 1
    Having access to the ducts makes things easier. Ducts might have small screws or tape holding them together or just fiction. If no screws/tape they should come apart with a bit of wiggle/waggle movement. Once apart then simple cleaning of the inside should work.
    – crip659
    Oct 16, 2023 at 19:44

2 Answers 2


Simply unscrew the duct boot (that's the part you can see into from above) from the duct itself, then unscrew/unnail the boot from the floor. Once it's out, you can clean to your heart's content.

If you can't get it clean enough (or your seeing signs of early rusting because the pee is acidic and eating through the galvanized coating), simply replace the boots. Cat pee is bad enough, even worse if it's being warmed and blown around the house... shudder


Apart from the excellent suggestion to remove and wash the ends of the ducts, you should make yourself aware of specifically targeted pet urine odor cleaning products.

Having had a cat with kidney issues, they proved very useful for getting the last bit of odor out of things not so easily washed or replaced.

  • This for sure - cat pee has some specific chemicals in to make it smell strong, for scent marking. You really have to get those broken down, and specific (normally enzymatic) cleaners are the best way to do that.
    – lupe
    Oct 17, 2023 at 8:37
  • But note that the enzymatics can have their own scent, which can be quite strong, so you may need to ventilate the house (open windows, fans) for quite a while if you use those.
    – Huesmann
    Oct 17, 2023 at 12:46
  • I would just saturate the vents with the spray, not unlike the cat did, so that it washes over the same path and drips out onto a bucket or rags in the basement. Seems easier than removing parts.
    – dandavis
    Oct 17, 2023 at 19:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.