The property you are considering buying has the potential to make you a lot of money. You only have one major problem, and this problem is the reason you can buy this property at such a low price. The problem is the smell, the smell that a lot of pets leave behind.

Should I seal or paint the floors and walls to trap odors? Will that solve your problem? Unfortunately, the answer is no.

Sealers are meant to block stains on walls so they don’t run off and stain new paint applied to a wall. They are not designed to seal or block gases (odors) from escaping or passing through. Some paints, but not most, produce a continuous membrane finish that is not permeable to gases. Consider, however, that you are only painting one of many sides of an object, such as drywall or a floor, this approach offers limited odor control and success.

Both fire and tobacco smoke are exceptions. But even long-term tobacco smoke contamination of walls and ceilings can be sealed only after most of the tobacco tars have been washed away with trisodium phosphate (TSP). Remaining tobacco smoke odor can be removed 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 smoke residue and completely eliminates odor in just 24 to 48 hours.

Sealing urine odors on the floor can work on plywood floors, but careful analysis of the process reveals some serious flaws. Sealing laminate flooring actually reduces the amount of water and water vapor reaching the urea salt (produced by urine waste) so that the salt does not produce the odor in the form of mercaptan gas.

However, when the floor is returned to service, small surface movements caused by occupant and furniture traffic will cause the sealants to crack and lose water vapor and escape mercaptan gas. The cracks are large enough to allow water vapor and mercaptan gas to escape, but too small to allow this liquid and water to enter to work on the urea salt. Also, floorboards have six sides. Sealing one side is not enough to fix the problem.

Using caulks or paint to seal concrete floors is more effective, but most caulks and paint are gas permeable. Also, scratches and wear spots in the sealant or paint will cause the mercaptan gas to leak back through the seal, creating the problem mentioned above.

Heavily contaminated wood and concrete floors present another problem. When urea salt gets wet with water extracted from wood or concrete, it expands and lifts sealers and paint from the floor. When these blisters burst, the odor returns.

So if sealing and painting don’t work, what does?