Last updated in July 2016
Wood floors can’t be beat for durability, but kids, pets, furniture, and everyday dirt can spoil a floor’s appearance or cause damage, and sunlight can yellow or fade floor finishes. At some point you’ll need to refinish your floors. That’s when things get messy. And smelly. And inconvenient. And expensive.
Because refinishing work is a dirty and painstaking process, even brave do-it-yourselfers usually hire pros for it. Despite the fact that many companies advertise “dustless” refinishing methods, sanding produces dust, even if performed by the most careful pro. In addition, most finishes are (to put it mildly) smelly. Most also emit volatile organic compounds (VOCs) that linger for days and are (to put it really mildly) bad for your health and the environment.
It’s time to have your floors sanded and refinished if—
- Bare wood is exposed in several areas.
- There are stains you can’t live with; they’ll require sanding or, in some cases, replacing the stained boards.
- The surface has yellowed or become discolored to an unacceptable point.
- You’d like to stain your floors a different color.
In these cases, sanding and refinishing is the only way to restore your floors’ uniform appearance. Although companies may make slightly different recommendations, the process of sanding and refinishing floors usually requires—
- Multiple sandings—usually three separate passes. The first pass uses coarse paper to remove the old finish; then one or two more passes using finer sandpaper to produce an even and smooth result.
- Repairing defects. Refinishers will drive any exposed nail heads below the surface, remove staples left over from carpeting, and fill holes and gouges with wood filler. If necessary, they can also replace boards that can’t be salvaged by refinishing.
- Cleaning away dust. Refinishers should make every effort to minimize dust during sanding, and then diligently vacuum and wipe down the entire area.
- Applying stain or a sealer. To help you choose a stain color, the refinisher can stain small areas—one or two square feet—with sample tints. Once you’ve made your choice, the other samples are sanded away. If you prefer the natural wood color, the refinisher may apply a natural stain—which retains the bare wood’s color—or a clear sealant. Some refinishers will recommend applying the surface coat directly to the bare wood without a sealant or natural stain, depending on the type of finish used.
- Applying a surface finish. Refinishers usually use polyurethane, applying at least two coats and often three. The refinisher should buff the floors at least once in between applying the first and second coats.
Bear in mind that floors can be sanded a finite number of times. Sanding removes wood, and repeated sandings will expose the interlocking grooves between boards. Solid-wood floors are generally 3/4-inch thick when new and will hold up to sanding three or more times. Engineered hardwood floors can also be sanded and refinished but typically hold up for only one sanding. Engineered floors layer hardwood—typically 3/8-inch wood—on top of a manufactured plywood-like laminate. If you’re not sure what type of floor you have, remove the baseboard molding or check around floor grates.
Types of Finishes
Surface finishes are the most common; they coat the surface of the floor and create a seal that protects the wood beneath it. Surface finishes are most commonly polyurethane.
Floors installed in the 1960s or earlier might still have a shellac or varnish finish, neither of which is used anymore.
The various surface finishes have different qualities but work the same way: Once applied, they dry and harden on top of the wood. You might think of it as a clear coat—when you touch the floor you touch the finish, not the wood itself.
You can ascertain that you have a surface finish by looking at existing scratches—or making a small scratch with a coin edge in an out-of-the way area. If a scratch produces a white line, you have a surface finish.
Penetrating finishes are much less common and substantially different from surface finishes. First, an oil is applied to bare wood, penetrating and sealing the surface. If the floors are to be stained, the stain is mixed into the oil base, and the floor is then waxed and buffed. The wax provides sheen and protection, and must be reapplied periodically. When you touch a floor with a penetrating finish, it will feel like you’re touching the wood itself. It’s less protective than surface finishes, but looks and feels more like the natural wood. Wax is making a bit of a comeback, as it is nontoxic and emits very low VOCs.
If your floor’s finish has worn through to bare wood in only a small area, a refinisher may be able to restore the area without sanding and refinishing the entire floor. Although spot repairs can save you most of the cost and mess of a full sanding and refinishing job, you may sacrifice something in terms of appearance, since it’s difficult—and sometimes impossible—to match exactly the appearance of a refinished small area to the rest of the floor. For this reason, spot treatments should usually be limited to areas that measure less than two square feet or so. Because surface finishes all tend to yellow over time, a newer finish is more likely to enjoy good results with a spot refinishing job, and floors left natural are also much easier to match than stained floors.
If you have a surface finish, no bare wood is exposed, and your floors are in generally good shape, consider recoating. Recoating skips the sanding, takes less time, and can cost less than half the price of a full sanding and refinishing job.
During recoating the refinisher will “screen” your floor, using a buffing machine with a fine-meshed screen—not sandpaper—to abrade the old finish. The abrasion allows a fresh coat of surface finish to adhere. The refinisher will then apply one or more coats of surface finish.
Choosing Finish Types
Polyurethane surface finishes are the most popular and most practical, as they are durable and easy to maintain. If you choose polyurethane, you’ll need to decide between an oil-based and a water-based product. Refinishers tend to be loyal to one type or the other, as well as to particular brands, and each has pros and cons.
Water-based polyurethane products offer several advantages. They dry in as little as two hours, allowing refinishers to apply multiple coats in a single day, which means workers can complete the job more quickly. They emit fewer VOCs, so they smell less, and the odor dissipates more quickly.
Water-based polyurethane appears clearer when applied (oil-based products may have a slight amber tint) and resists further yellowing—or “ambering”—better than oil-based products. Some consumers may not want the amber coloration, but others believe it gives the floor a sense of warmth.
One advantage of oil-based products is that they are easier to apply in a smooth, consistent finish, without applicator marks. And oil-based products generally have more solids, so the job usually can be performed with fewer coats than water-based.
Since both oil-based and water-based finishes can produce fully satisfactory results, your refinisher’s preference may determine your decision.
If you are especially concerned about VOCs and need to have your floors sanded down to bare wood, penetrating finishes are another option. But be aware that wax is less protective than polyurethane and requires regular—usually annual—maintenance, namely cleaning with a special product, buffing, and waxing. In contrast, a surface finish like polyurethane is not likely to require recoating for at least three years, and can last 10 years or more without any maintenance but cleaning.
Some soy-based polyurethane products and other alternatives virtually eliminate VOCs. But because they are relatively new to the market, refinishers tend to be leery of them; refinishers who had used them told us they’re difficult to work with. These products can also cost two to three times more than conventional products—possibly contributing an extra five to 10 percent to the overall cost of sanding and refinishing jobs.
Choosing a Refinishing Service
Carefully choose a refinishing service for your job. Start by reviewing the ratings available here at Checkbook.org. You’ll see that in addition to bearing a messy, smelly refinishing process, many homeowners endure lousy service. Roughly one in five customer reviews is negative, a lower satisfaction rate than most other types of home improvement services. Even more alarming: Most complaints relate to sloppy work, sometimes so sloppy that flooring was ruined.
It also pays big to shop around for a good price. Most companies can provide price estimates via phone or email based on the type of flooring you have, its general condition, the square footage and configuration of the area to be refinished, type of stain, and type of finish.
After gathering phone or email estimates, invite one or two of the lowest-priced companies to drop by and provide a written final price quote and proposal.
You’ll find that companies are apt to quote on their preferred products and practices—which will not necessarily be precisely the same from company to company. But gathering prices lets you identify companies that charge reasonable fees. You will find substantial price differences among firms you call.
Our undercover shoppers obtained quotes from a sample of area refinishers for sanding and refinishing two rooms totaling 500 square feet. Companies were asked to quote their prices for applying oil-based and water-based polyurethane finishes. The prices we obtained are shown on the table at the end of this article. As you can see, we found enormous differences—for example, from $1,000 to $1,750 or more for a water-based finish.
Before work begins, take time to discuss several points with your refinisher:
- Ask about stained or damaged areas. Some stains (pet stains are notorious) can be impossible to remove, even with sanding. They require deeper sanding, which removes more of the wood. You can have damaged wood replaced, but that raises the price. Ask for a recommendation and an estimated price for dealing with it. You may decide you can live with imperfections.
- Specify whether closet floors are to be refinished.
- Ask about baseboard/quarter-round moldings. Some refinishers prefer to sand right up to the moldings and leave them as they are, rather than remove them. Because this can leave scratches and marks on the molding, and a small visible edge of unsanded flooring below the molding, you might want to insist on having quarter-round moldings removed and replaced (or new ones installed if you have none now). Specify what you want done and who is to do it.
- Ask about stain selection, especially if you want it to match another area. Before the work begins, the company should apply stain samples for your approval. If no stain will be used (for a natural finish), ask whether it will use a clear stain or a sealer coat before applying the surface finish.
- Ask what finish the company recommends, and how many coats will be applied. Discuss the rationale for the recommendation. Many companies prefer one method over another. For polyurethane, discuss and specify whether you want gloss, semi-gloss, or a satin finish. Gloss is the shiniest, but shows scratches and other nicks more than the others.
- Ask for Material Safety Data Sheets for all solvents. The refinisher is required to provide them. These sheets indicate VOC levels and provide other information you can use to compare products other companies recommend. Generally, the higher the solids level the more durable. The lower the VOCs the better. If you are particularly concerned about VOCs and odors, ask if the company has experience with, and can recommend, low- or no-VOC products.
- Discuss how the company handles dust and cleanup. Commercial sanding equipment should be equipped with vacuums and collector bags. Some companies use “dustless systems,” which employ large external vacuum units connected to sanding equipment with hoses. These systems help, but there’s really no such thing as dustless floor refinishing. The key to minimizing dust is worker diligence while sanding and afterward during cleanup.
- Discuss preparation. Some companies will take up carpeting or move furniture—but remember that floor refinishers are unlikely to be insured for damage they cause while moving furniture and belongings.
- Ask whether the company will use plastic to cover heating/cooling vents and seal off the room from other areas in your home. It should.
- Ask for a work schedule, so you’ll know when rooms are off-limits and how long the work will take.
- Ask for a guarantee. At a minimum, request a year on workmanship and finish, against defects like cracking, peeling, bubbling, and clouding.
- Ask about payment terms. It’s best to pay in full after the work is complete.
- Ask about insurance. Make sure the company can provide proof of workers’ compensation and general liability insurance. And ask whether the company’s workers are company employees or subcontractors. If they are subcontractors, get proof of insurance for them, too.
- Get a written, fixed-price contract. The contract should state a price and detail all discussed and agreed-to terms—type of finish, number of coats, stain (if any) to be used, how moldings will be treated, dust protection systems to be used, preparations the firm will make, work schedule, payment schedule, guarantee, etc.
If you are refinishing only one or two rooms, you can probably live around the inconvenience. But if the work takes place in a large common area, or includes a stairway, get outta there. And you might not be comfortable returning for several days or even a week, depending on the type of finish. Once the first coat of finish is applied, your family and pets won’t be able to walk across the floor until the last coat has dried. Also, the heating and cooling system will be turned off during sanding to avoid circulating dust.
After the last coat of finish is applied, make sure the refinisher specifies when you can walk on the new finish, and if you are moving your own furniture, how long before you can replace furniture and rugs. Before replacing furniture, install felt pads or glides on legs. You won’t want to scratch your newly refinished floors.
When the finish has dried, inspect the entire area. Look for imperfections like bubbling or an orange-peel effect. Bring problems to the company’s attention immediately.
Illustrative Floor Refinishing PricesCompanies were asked to quote prices to refinish 500 square feet of flooring and coat using a natural finish (no staining). Among several other details, companies were informed that the flooring is solid oak, tongue-in-groove strip, and in overall good shape.
|Price quoted for oil-based finish||Price quoted for water-based finish|
|Amazing Hardwood Floor Svc, San Lorenzo, 510-523-5346||$1,750||$1,950|
|Amber Flooring, Emeryville, 510-652-6161||$1,500||$1,600|
|American Hardwood Floor, San Leandro, 510-773-0347||$1,700||$1,700|
|Bay Floor Crafters, San Francisco, 415-694-0827||No quote||$1,500|
|Big Oak Hardwood Floor, San Mateo, 650-591-8651||$2,300||$2,500|
|Bruce Williams Wood Floors, Oakland, 510-652-8121||$1,750||$1,750|
|California Carpet & Rugs, San Francisco, 415-487-3636||No quote||$2,500|
|Caribbean Floor, Redwood City, 650-369-8755||$3,750||$3,750|
|Clark’s Hardwood Floors, Campbell, 408-866-5485||$2,500||$2,500|
|Elegant Floors, Sunnyvale, 650-961-1339||$1,750-$2,250||$1,750-$2,250|
|Glenn Allen Hardwood Systems, Concord, 925-383-6596||$1,750||$1,750|
|Johnson Brothers Flooring, Lafayette, 925-299-9105||No quote||$1,325|
|Lee Floor Sanding, Oakland, 888-318-0888||$1,250||$1,450|
|Marin Hardwood Floors, Kentfield, 415-456-1639||$2,250||$2,250|
|Mattingly & Sons, Concord, 925-686-2955||$2,250||$2,250|
|New Method Floor, Oakland, 510-530-3636||$2,300||$2,300|
|Prestige Hardwood Floors, Walnut Creek, 925-200-2332||$1,750||$1,750|
|Seuss Flooring, Moraga, 925-376-3000||$3,000||$3,000|
|Slaughterbeck Floors, Campbell, 408-379-5813||$2,500||$3,250|
|T & T Floors, Oakland, 510-536-8333||$1,200||$1,400|
|Town & Country Flooring, Redwood City, 650-329-8926||$2,250-$2,500||$2,500|
|Tulip Hardwood Floors, Richmond, 510-558-2030||$2,000||$2,000|
|Van Briggle Floors, Campbell, 408-371-2003||$2,250||$2,500|