Do I need to paint floor first?

June 18, 2019 4:51 PM

I am having the carpet torn out of one room and replaced with 3/4" hardwood plank flooring. The carpet has a considerable amount of dog urine damage. One person has told me that the installer should paint the plywood subfloor with Kilz primer first to contain the urine odor.

Does this seem necessary? Has anyone heard of urine odor coming through the flooring from the subfloor? Neither Carpet Exchange nor the installer has ever mentioned anything like this to me.

posted by Rad_Boy to Home & Garden (17 answers total)

You could do this yourself, quickly; painting is very fast if you use a roller and don’t have to care about screwing up carpet. This was the advice I received when I moved into my first house where dogs, cats and rabbits had been allowed to run freely- I could faintly smell the urine that had reached the subfloor even after I removed the carpet and the coat of Kilz I rolled on did indeed solve the problem.
posted by charmedimsure at 4:56 PM on June 18, 2019 [2 favorites]

I've used kilz on concrete subfloor for similar reasons. If the subfloor definitely has urine damage, the odor might come through. Kilz is cheap and you won't be able to go back and do it later.
posted by mmc at 4:57 PM on June 18, 2019

Yes, my understanding is that the subfloor is likely to be in bad shape if there's been a considerable amount of pet urine. Odor-sealing primer now is likely cheaper and easier than either replacing the actual subfloor now or tearing the whole thing up and doing the primer later if you decide too late that you needed it.
posted by Stacey at 4:58 PM on June 18, 2019 [2 favorites]

Ohhhhhh yeaaahhh...urine smell does indeed come through new floor if it is not dealt with. Urine regret and your flooring is a bad pairing.
posted by jadepearl at 5:23 PM on June 18, 2019 [2 favorites]

Speaking from experience, yes, definitely give it a coat or two of Kilz. If it's a plywood subfloor, if you are able to pull up the carpet a week beforehand, give the subfloor where the urine spots might be a good dose of Nature's Miracle or some other enzymatic odor remover. Apply until the surface is damp (you may need a few bottles depending on how widespread the damage is), and let it soak in and then air-dry. Then paint with Kilz.

We had elderly cats who developed the peeing-everywhere-but-the-litterbox syndrome in their late life and we did the above both upstairs (plywood) and downstairs (concrete) and have no residual odor. Ultimately it's impossible to tell if any of it actually made a difference, but as mmc states, for the price and effort it's totally worth it to do now, because you don't want to get a whiff of dog pee after the fact.

I don't know about the installer doing it though - it needs a few hours to dry before you should be putting anything on it. Guess it depends on if they're willing to wait or make two trips.
posted by SquidLips at 5:28 PM on June 18, 2019 [3 favorites]

Builder's felt , roofing felt is heavier, can be used , dampens sound helps stops squeaks forms a barrier between the subfloor and floor , I'd kilz it too . Talk to your installer.
posted by hortense at 5:51 PM on June 18, 2019

Kilz has a reputation for being highly toxic, and here's a question from a Mefite who used it in a situation exactly like yours and thinks it could be responsible for ongoing "headaches/nausea".

I think you should use a non-toxic bacterial culture and enzyme based deodorizer (Bac-out) instead.
posted by jamjam at 6:07 PM on June 18, 2019

Oh no do not do this. BTW that was my question jamjam linked. So bad. I mean, it could have been the laminate, but it's probably the Kilz, and there's NO getting it out; even removing the subfloor is practically impossible because there are just so. many. nails. We ended up removing the laminate, buying some special zero-VOC sealant, and painting that all over the subfloor.

Besides, as SquidLips said:

Ultimately it's impossible to tell if any of it actually made a difference,

What I would try is enzyme solution and/or zero VOC coating, just on the spots that are there.
posted by amtho at 7:18 PM on June 18, 2019

Yes, you need to either Zilz it or use some type of VOC coating. If not, you WILL eventually regret it. If there is significiant damage in one place, or if you have damage that indicates that urine has run under the wall, you need to do some exploration to see if the wallboard has absorbed the odor. Getting the pee smell out of a floor is hard. Don't skimp on the prep, if you do, you will have very expensive regrets.
posted by BlueHorse at 7:42 PM on June 18, 2019

Unless you do something to thoroughly block the odor, any dog in that room will immediately sniff out the urine stains and, most likely, mark the same spot.

FWIW, we've put Kilz under every carpet in our house and are still alive and kicking.
posted by DrGail at 8:09 PM on June 18, 2019 [4 favorites]

I had this problem before Kilz and I used just plain paint with no tint and a bottle of vanilla extract per gallon. worked. did not smell like vanilla, either. friend told me to do this. you could get a piece of plywood and give this method a test run if you doubt it.
posted by cda at 11:13 PM on June 18, 2019 [1 favorite]

I did this when replacing the floor under what turned out to be my elderly cat's favorite pee spot. Kilz (the brand) makes a couple of different formulations, and we used the super-low VOC one all over the house with no problems. (We had nicotine issues on the walls as well.) I'd recommend it.
posted by restless_nomad at 6:44 AM on June 19, 2019

Has anyone heard of urine odor coming through the flooring from the subfloor?

Oh hell yes, absolutely. I have heard of this, I have experienced this (in a close friend's house), this is definitely a thing. Seal them with something like Kilz even if you don't sense a smell coming from the subfloors now, because changes in humidity and such can make the ghost of whiffy dog pee fade in and out.
posted by desuetude at 8:02 AM on June 19, 2019

I would use Nature's Miracle or another enzyme cleaner liberally, let it dry, then use the strongest formula of Killz.
posted by theora55 at 8:02 AM on June 19, 2019

I Kilz painted the subfloor in the master bedroom of my old house before installing nail-down bamboo plank. I used Kilz in that room only to remediate some mildew; I didn't paint the subfloor elsewhere in the house.

The bamboo floor squeaked in that room (only) from the day I installed it until the day I sold the house.
posted by workerant at 8:22 AM on June 19, 2019

I did this - Nature's Miracle, two layers of Kilz, felt soundproofing layer, then flooring. Two years later, everything still smells fine and subsequent cats seem unaware of the history of the place.
posted by mersen at 11:33 AM on June 19, 2019

I used Kilz on our subfloor after ripping out the carpet and pad to prepare for a contractor to install our wood floor. He could still smell the dog urine (we couldn’t) and recommended upgrading our underlayment to Pergo Gold. Apparently it is made for this kind of situation. It didn’t cost much -if any -more than the run of the mill underlayment we had. We just did this in May so I can’t attest to long term efficacy of any of it, but it does seem like treating the floor with something and then using the best underlayment is the best way to go.
posted by ChristineSings at 6:28 PM on June 19, 2019