Pet Urine Stains on Sub-flooring

The product I have used on sub-floors is called Killz. It is not too expensive and one gallon will go a long way. One thing to remember though, it is not "paint", in other words, it is not necessary to have a good coat on. See through is fine as long as it is applied evenly over all affected areas. it will work on walls that have been sprayed as well.

I am in the process of cleaning cat spray out of a pillow top mattress cover. I am going to try some of your ideas, I will let you know what works!

You could put a layer of plastic sheeting between the floor and the pad. I actually did this, but I put the plastic between the carpet and pad so the pad and floor wouldn't get soaked if our dogs or cats had an accident.

Hello,
We just went through this! My husband used shellac. He applied it 4 times with it drying in between applications. This was recommend to us by our carpet installer. It worked great!

Hi. A single wetting of dog urine would not have terrible odor as compared to cat urine. This sub floor must have been peed on repeatedly. I bought a house and tore out the carpets to find a urine stain here and there. I took my pets to a different location. (Send kids out of the house too.) I opened all the windows, and turned on fans.

I carefully poured a bit of pure bleach on the stains, and spread it evenly with a plastic dish brush. Careful, the bubbling you will see is dangerous gases coming off. Good ventilation is extremely important. However, once it was done reacting, and the fans removed the gases from the house and helped dry the wood, the traces of urine were gone. I laid my new flooring over top.

However, if your sub floor is sodden with urine, it will have to be replaced. The fibers of the wood would be compromised, and the floor unstable. I have heard that there is a paint for sealing odors in after a fire that will seal in the scent of urine. I don't know what it is called however. It is pricey.