A: A screen and coat will remove light surface scratches and clean any dirt embedded into the surface. It will also protect the wood from further scratching. If you choose a high gloss finish, it will also make the floor very shiny and new looking.
A screen and coat will NOT remove deep stains, scratches or rust spots. Also, it requires that there is no wax buildup on the floor. This means that if the floor was ever waxed or even cleaned with wax products, the polyurethane would not dry properly. This is not usually the case, but of course we would test to make sure we can screen and coat. In the event that the floor has wax, your other option would be a complete sand and refinish.
A sand and refinish involves sanding off all existing finish and going down to the bare wood. The floor is then sanded with a fine grit to remove all scratches from the heavy sanding process. From there, we apply the finish. For oil based finish, we apply a sealer and two coats of polyurethane. If a stain is desired, it would be used in place of the sealer. For water based finish, we would apply a sealer and three coats of water based polyurethane. If you want to use a stain with a water based finish, it can be used, but it would have to be oil based stain and would need a couple of extra days to dry before the finish can be applied.
A sand and finish will remove most, if not all, scratches in the wood unless they are too deep. All surface scratches, dirt and stains would be removed. Water or urine stains are another story. If the stains are too deep, they will not come out. Other than that, the floor looks nearly brand new after a sand and finish. We offer a 7 year limited warranty against the finish chipping, cracking, or peeling under normal residential use.
The natural color of a finished floor is comparable to a honey color. The floors do amber over time though. A screen and coat does not change the color of a floor. A sand and refinish will remove any existing stain.