If you have a urine smell in your home it's most likely coming from your carpet. This video takes you through the first steps of how to remove urine from carpet. Like the first step of any problem you have to figure out where the urine is. There are many ways to locate urine deposits in your carpet. the first and easiest way to find urine is to look for a visible stain in the carpet fibers. Most of the time when urine is deposited in carpet it will result in a discoloration of the carpet itself. Sometimes it might be a yellow stain and other times it might be a darkening of the carpet.
The second way and usually the most successful way to find urine in the carpet is by sniffing it out. Urine crystals release ammonia when the hydrated. On Tampa FL where we have a lot of moisture in the air the urine crystals will usually be quite pungent. The more moisture the more ammonia is released. That's why if urine in the carpet gets wet it smells so bad.
There are more technical ways of finding urine in the carpet, like using a UV flash light or a moisture detector. These are tools that professional carpet cleaners use and not common to most households. If your smelling a urine odor in a room but you are unable to locate the source of the smell it might be time to call a professional carpet cleaner who knows how to remove urine from carpet.