Screen-and-Recoat vs. Full Sand-and-Finish

It means abrading the existing finish just enough that a new coat will bond to it, without sanding into the wood. A fine abrasive screen on a floor buffer is the classic tool; finish manufacturers' recoat instructions also call for fine-grit screens, conditioning pads, diamond abrasive discs or abrasive brushes, depending on the system. The National Wood Flooring Association's consumer term for the whole job is a maintenance coat.

There is no universal interval — it depends on traffic, whether shoes come off, whether grit gets tracked in, and what finish is on the floor. A National Wood Flooring Association consumer fact sheet charts a maintenance coat every three to five years and a full sand and refinish every few decades, while noting that schedules vary with use, wear and lifestyle. The useful trigger is condition rather than time: recoat while the finish is dulled but still intact everywhere.

Sometimes — start with the flooring manufacturer's warranty. One prefinished-flooring maker states that adding a polyurethane coat voids its warranty and can leave an uneven finish; another lists a maintenance coat among its care options; and finish makers publish recoat systems specifically for factory finishes, including aluminum-oxide ones. Whatever the system, test the complete process in an inconspicuous area before coating the floor.

Scratches confined to the finish, yes — the new coat fills and levels them. Scratches into the wood, no. They will still be visible, now under a layer of fresh finish, which is the outcome that leads people to conclude a recoat did not work when in fact the floor needed a full sand.

Yes, and it is one of the more useful things a recoat does. Moving from gloss to satin or matte changes how a floor reads considerably, and it also hides fine scratching better, since lower-sheen finishes scatter light rather than reflecting it in a way that highlights every mark.

With simple checks that belong in a professional's pre-recoat inspection. One finish maker's paste-wax check rubs a little mineral spirits on a clean white cloth in a low-traffic area; film or discoloration on the cloth means wax is likely, and its recoat system should not be used. Its acrylic-polish check places a few drops of a corrosive test solution on the floor, waits 30 seconds, and looks for a change in sheen that shows an acrylic coating has to come off before any new finish.

As long as the finish needs — a recoat does not shorten cure. Data sheets for common waterborne floor finishes allow walking after about 24 hours and list full cure at three to seven days, depending on the product, and ask for rugs to stay off until the finish has fully cured or for at least two weeks. One finish maker's homeowner schedule puts furniture back at two to three days and rugs at two weeks.

Less than people fear when it is done well, and no published count of possible sandings was found. The National Wood Flooring Association says a professional refinisher removes very little wood to make repairs — generally 1/32 inch or less — and that the number of times a floor can be sanded depends on the contractor's skill, the equipment, the wear-layer thickness, flatness and condition. Its voluntary Certified Refinishable program for engineered flooring requires at least a 2.5 mm wear layer on factory-finished products and 3.2 mm on unfinished ones.

Yes. The architectural-coating rules in the Sacramento Metropolitan, Placer County, El Dorado County, Yolo-Solano and Bay Area air districts regulate the product by category, and clear floor finishes fall under wood coatings at 275 grams per liter. Sacramento's rule applies to anyone who sells, makes or applies the coating in the district, and its exemptions cover aerosols, containers of one liter or less and colorants, not maintenance coats; none of the other four rules has a recoat exemption. Healdsburg's district sets limits by product type instead.