The property you are considering buying has the potential to make you a lot of money. Only it has one major problem, and this problem is the reason you are able to buy this property at such a bargain. The problem is odor, odor left behind by a host of pets.
Should you seal or paint the floors and walls to trap the odors? Will that solve the problem for you? Unfortunately, the answer is no.
Sealers are intended to block stains on walls from bleeding through and staining new paint applied to a wall. They are not designed to seal or block gases (odors) from escaping or passing through. Some-but not most-paints do produce a continuous membrane finish that is not gas permeable. Consider, however, that only one of many sides of an object like a piece of drywall or flooring is being painted, this approach offers limited odor control and success.
Both fire and tobacco smoke are exceptions. But even long-term contamination of walls and ceilings with tobacco smoke can be sealed in only after most of the tobacco tars have been washed away with Tri-Sodium Phosphate (TSP). The remaining tobacco smoke odor can be eliminated with chlorine dioxide gas. It is a small packet of powders that when exposed to water vapor, produces a gas called chlorine dioxide. This gas oxidizes the smoke residue and removes the odor completely in as little as 24 to 48 hours.
Sealing urine odors into flooring can work on plywood flooring, but a careful analysis of the process reveals some serious flaws. Sealing sheet flooring actually reduces the amount of water and water vapor getting to the urea salt (produced by the urine residue) so that the salt does not produce the odor in the form of mercaptan gas.
When the floor is put back in to service, however, small movements of the surface caused by occupant traffic and furniture will cause the sealers to crack and leak water vapor in and mercaptan gas out. The cracks are large enough to allow water vapor and mercaptan gas to escape, but too small to allow this and water liquid to get in to work on the urea salt. Also, floor boards have six sides. Sealing one side is not enough to fix the problem.
Using sealers or paint to seal concrete floors is more effective, but most sealers and paint are gas permeable. Additionally, scratches and wear spots in the sealer or paint will cause mercaptan gas to leak past the seal again, creating the problem mentioned above.
Heavily contaminated wood and concrete flooring present yet another problem. When the urea salt gets wet from water drawn from the wood or concrete, it expands and will actually lift sealers and paint off the floor. When these blisters burst, the odor returns.
So if sealing and painting doesn't work, what does?