Male cats tend to be the largest culprits for urine damage. When a male cat is not neutered, they will mark their territory leaving many surface areas damaged. This kind of damage can go unnoticed for days or even months. Once it penetrates flooring, and often sub-flooring, it makes it difficult to remove.
The best option in this case, is to have your cat neutered by a veterinarian- a simple, safe practice that is often included when you adopt a cat from a shelter or rescue.
If your cat is not adopted from a shelter, it would be advisable to make an appointment with your cats vet. The sooner the better, because spraying can get out of hand very quickly!