The phrase “screen and recoat” describes the process of sprucing up an existing coat of polyurethane by top-coating it. (This is sometimes referred to as "buff and coat" because the screen is often driven across the floor by a buffer). But the inclusion of the word ‘screen’ is vital because in order to get a new coat to adhere to the old one you must lightly sand or ‘screen’ it.
A screen is just a mesh encrusted with abrasive particles. Because it is a mesh, there are fewer abrasive particles per square inch, making it generally less aggressive than sandpaper (a 120-grit sanding screen, for example, will be less aggressive than 120-grit sandpaper.)
Screens are also used under thick soft pads that further soften the cutting action of the screen. This is desirable because floor screening should only leave enough texture in the floor to allow a new coat of polyurethane to bond; screening should remove only a tiny fraction of the existing finish.
Part of a Regular Maintenance Program
That was a long-winded explanation that only just hinted at the purpose of a screen and recoat. It is simply part of the regular maintenance of a hardwood floor that has been finished by polyurethane. Polyurethane is considered a protective sacrificial coat. Over time, the friction of day-to-day living slowly removes the plastic in the finish.
That layer gets thinner and more scratched each year—as it should—because its job is to keep damage away from the wood below. But if you let that protective coat deteriorate for too long, it will eventually expose bare wood to assaults from doggy toenails, coffee spills and baby drool, causing damage that can only be repaired by sanding the whole floor. This, you do not want. So, every few years, well before the protective coat has grown too thin, you refresh it with another coat. The crucial word is “before;” you have to recoat a floor before you see damage, which is hard for some people because they think they’re leaving money on the table by top-coating what appears to be a perfectly good floor finish.
But polyurethane on floors is kind of like sunscreen on skin: not only do you need to put on a good thick layer before you expose it to the sun; you must re-apply it periodically because it wears off. Once sunburn begins to appear, it is too late to start applying protection. Protection is always less costly than the damage that results from not having it.
Can Any Hardwood Floor Be Screen and Coated?
Alas, no. Some floors are just too far-gone to be saved by a simple recoat. If there is damage at the level of the wood on any part of the floor, including dents, deep scratches, wear spots caused by heavy traffic (look for the telltale gray patches at doorways or in front of the sink), UV discoloration around rugs, and pet stains. While it is physically possible to recoat floors like these, and even have the new coat bond well, the damage will still be visible through the fresh coat of finish, effectively preserved under plastic. Another reason not all floors can be screened and Coated is how they have been cared for. If the floors have been previously cleaned with any store bought product such as Murphy’s Oil Soap, Endust, Mop and Glo, Pine-Sol, Wet Swiffer’s, Pledge etc. You have not created a wax coating over your floors and they cannot be Screen & Coated, as the polyurethane finish will peel. The only thing we recommend using to clean your floors is Bona Hardwood Floor Cleaner.