We purchased a house in September of 2003. The Woman had the windows wide open when we first saw it and no smell was apparent. On our closing inspection we noticed a slight smell but planned on taking up all the carpets anyway so figured the smell would go away then.
After removing all the carpets, the smell was actually worse and we found the urine had soaked into the sub floors, sill plate, into the heating grates, and soaked some corners of the drywall. I removed all baseboards (and tossed them), cut out affected drywall, sanded the sub floor, and soaked everything with many gallons of "nature's miracle". I then applied a thick coat of Kilz original oil based sealer. This process has taken care of 99% of the odor but on humid days we still smell the cats.
Does anyone have any additional suggestions out there? I was thinking about an air purifier or sonic breeze or something along those lines.
Thanks