Is refinishing my only option for damaged wood floors?
Q: Our very old wood floors are in good shape and were refinished right before we bought our house 10 years ago. But now there is very noticeable wear in a few spots, chiefly in the entryway. How should we address this?
A: It depends on whether the finish is just worn, meaning it looks dull, or it has worn through, meaning dirt from shoes is getting ground into the wood itself. And, of course, it depends on your budget and what degree of perfection you want.
When the finish is worn through, the best option is to refinish, a process that involves sanding off the old finish and enough wood to erase scratches and dents, repairing any other damage, then applying stain (if desired) and multiple layers of clear finish. The steps take time, so the process is expensive.
But if the finish is just dull, refinishing probably isn’t the best option. Most old wood floors are made from solid boards with interlocking tongue-and-groove edges. The boards are held down by nails driven at an angle through the tongues so no metal shows on the top of the floor. However, the nailheads are only about a quarter-inch below the surface when the floor is first installed (and even less if the flooring is an engineered type, with a thinner wear layer). Each time the floor is refinished, a little of the wood, maybe 1/32 inch, gets turned into sawdust. After the floor has been refinished several times, maybe four or five, the nailheads are too close to the surface to sand any further. At that point, the floor needs to be painted, covered with carpet or other flooring, or replaced. So refinishing isn’t just expensive; it also shortens the life of the floors, meaning it really ought to be done only when needed.
Paying attention to the finish and noticing when it just begins to become dull gives you a better, less costly option. Instead of sanding off the finish and starting over, you can simply restore the finish by adding another layer. To get new finish to grip better, a recoating company needs to clean the floor thoroughly and create miniature scratches on the old finish using chemicals or a machine with an abrasive screen (rather than sandpaper).
Many companies that refinish wood floors also offer recoating. Companies with terms such as “one-day” or “sandless” in their names emphasize this service, although they may also offer the full treatment. But the advertising pitch is correct: If a floor just needs to be recoated, the whole process might take only a day, and it won’t fill the house with sawdust. Greg Johnson, one of the owners of Sandless in Seattle, said his company needs to assess a floor in person before committing to a process, but if a floor is in good enough condition for recoating, it might cost around $2 a square foot. Full refinishing runs $10 to $12 a square foot.
There is a big caveat, though: If you have used dusting sprays that contain silicone, the residue could keep new finish from sticking and curing correctly. To remove silicone overspray, General Finishes, a manufacturer of floor finishes, says to scrub with Spic and Span Multi-Purpose Cleaner ($3.59 for a 32-ounce spray bottle at Ace Hardware) and warm water using a gray (ultrafine) scrub pad. Then wipe off residue with denatured alcohol and, after the floor dries, apply three coats of dewaxed shellac (Zinsser Bulls Eye SealCoat is $22.99 a quart at Ace), allowing drying time between each coat.
After all that, apply floor finish to a test area, let the finish dry, then see if it scrapes off when you rub it with the edge of a blunt butter knife or a nickel. (A nickel, or a penny, works well because it has a smooth edge. A dime or a quarter has ridges.) If the finish peels up, or if it dries with little “fish-eye” bare spots, there is still silicone and new finish isn’t an option. Resanding the floor would probably remove it, but even then, there are no guarantees that new finish will stick. You say you’ve noticed wear mostly in an entry. If you’ve used dusting sprays with silicone there, perhaps all you need is an area rug big enough to hide the worn spots, at least until more sections of the floor start to show wear.
Even though professional floor-finishers caution that it’s nearly impossible to recoat a section of a floor so it blends in perfectly, there’s no rule against doing it if you are willing to see some unevenness, especially at first. Just be sure to scuff up the old finish until it’s dull, using fine sandpaper or a scrub pad, and wipe off all the residue. Recoat entire boards. To keep from smearing finish onto adjoining boards, mask them off with painter’s tape.
Whether you are recoating the whole floor or just tackling a section, it probably makes sense to use a water-based — rather than oil-based — floor finish, even if the old finish was oil-based. Oil-based floor finishes make wood look more amber, while water-based finishes dry clear. But if there is an oil finish underneath, a clear coat on top won’t affect the color. And, in general, it’s OK to apply a water-based floor finish over an oil-based finish, but not the other way around because of differences in how stiff they are. Plus, water-based finishes dry faster and smell less.
If you spot-recoat, expect the sheen to be a little different from on the surrounding floor, even if you are able to find the same product that was used initially. Over time, the sheen will probably even out as the new finish acquires scuff marks mimicking those on the rest the floor.