Refinishing Wood Floors — Exacting but Rewarding

Few improvements to a home are as satisfying as newly finished hardwood floors. Rich, natural wood tones in a floor enhance any room and bring out a home’s best features. Synthetic floor finishes on the market today offer long life and easy maintenance, with the result that wood floors no longer need daily attention.

Wood floors installed in new homes are sanded to prepare them for sealing, staining, and finishing; floors newly installed in older homes get the same treatment. But the most common reason for refinishing is simply to rejuvenate a worn and dam aged floor, or perhaps to give new life to one that’s been hidden under carpeting for many years.

Refinishing a wood floor is a project that many homeowners consider doing themselves, if only to save the cost of having the job done by a professional.

The specific equipment needed — a drum sander, a disk sander, and a buffer — can be rented. Still, the work requires considerable patience and care; a single misstep can cause irreparable damage. And a re finishing project is likely to be time-consuming, messy, and disruptive to your general household comfort.

So before undertaking a complete sanding and refinishing job, investigate the wood re conditioning products available at hardware stores and home improvement centers. If you do decide that a thorough refinishing is in order, you have a third alternative to doing the complete job yourself or paying to have it done.

Sharing the work. Part of the cost of a professional refinishing job covers the preparatory work that must be completed before the actual sanding begins. But this is work that you can pretty easily do yourself.

In general, it will involve just taking up molding from around the baseboards, removing floor grates and other fixtures, and generally cleaning the surface of the floor. It might also include driving protruding nails below the surface with a nailset and filling the nail holes and any other gouges or dents with wood putty.

Fig. 97-0

So as an alternative to having the complete job done for you or doing it all yourself, get a couple of professional estimates for sanding and finishing only. The estimates, or “quotes,” should cover all materials and labor necessary to complete the job; you can get everything ready before the professional appears.

Inspect and repair floors before refinishing

Before you get on with the serious business of refinishing a floor, all floor problems should be corrected first — not only surface blemishes like damaged boards, but structural problems as well. The whole floor area, from below as well as from above, should be given a good examination (see “Locating the cause”).

Sagging floors, squeaks, and loose subflooring are problems that are likely to get worse in the future. There’s no better time to correct such problems than just before your floors are refinished. You’ll find suggested remedies.

Choosing a finish

Floor finishing materials are of two general types — penetrating sealers and surface finishes.

Penetrating sealers actually penetrate the pores and become an integral part of the wood. The finish wears only as the wood wears. It can be retouched in heavy traffic areas without creating a patched appearance.

These sealers can be used clear or tinted, or purchased in premixed stain colors. Normally, two coats are required. Buffing a penetrating sealer while still wet will result in a satin sheen. A final coat of paste or liquid wax — but not a water-base wax — is recommended.

Some types of wood require a sealer before the finish coat; discuss this with your paint dealer. If you do plan to use a sealer as a first coat under a surface finish, check with your dealer to make sure the two products are compatible.

Surface finishes provide a clear coating over stained or sealed wood. In general, polyurethanes have replaced traditional finishes like varnish, shellac, and lacquer. Polyurethanes are blends of synthetic resins, plastic compounds, and other film-forming ingredients that produce an extremely durable, moisture-resistant surface. High gloss or satin polyurethane finishes are available.

Though some makers of urethanes claim that no waxing is necessary, hardwood flooring manufacturers believe that waxing over a polyurethane finish will produce a better appearance and give longer wear.

If you’re going to refinish a softwood floor, it may be necessary to seal it before staining, or to use a sealer mixed with stain, to achieve a uniform color. Ask your dealer what products to use and how to use them.

If you’re refinishing a wood block floor made of prefinished tiles, ask the supplier or manufacturer to recommend compatible sealers and finishes.

Many tiles are made with rounded or beveled edges — making it impossible to remove the old finish between tiles by machine sanding. If you’re re finishing such tiles, you’ll want to choose a finish that will match or blend with the old finish, which will remain on the tile edges.

Tools and supplies

The basic heavy-duty equipment you’ll need to refinish a floor is available at most equipment rental companies. Often used by people who aren’t wholly familiar with its operation, this machinery is sometimes abused. Take care to check over all equipment you rent, and ask that it be tested before hauling it home.

Floor sander. The workhorse you’ll need is the basic drum sander, designed specifically for stripping old finishes off wood floors and producing a finely sanded surface ready for sealing and finishing.

Drum sanders come in several commercial models, but look for one that has a tilt-up lever that makes it possible to raise the drum off the floor without having to lift the machine. Be sure to get a machine with a dust bag. This won’t eliminate dust, but it will cut down the quantity. Check to see that the machine operates on 110 volts and doesn’t require 220-volt outlets. Most sanders have three-prong plugs, so if you don’t have outlets that take three-prong plugs, you’ll need an adapter. If you have to use an adapter, make sure it’s grounded properly.

Fig. 98-0

Before you take the sander home, ask the rental agent to show you how to load the drum and make sure he provides the wrenches needed; it’s a relatively simple procedure if you have the right wrenches and know which wrench to turn in what direction. Also ask for tips on operating the machine. De spite its size, a drum sander is a delicate piece of equipment to operate.

Fig. 98-1: Use wrench to open slot in drum (sander must be unplugged); wrap sandpaper around drum, tucking ends into slot so paper is tight. To close slot and secure sand paper, turn wrench in opposite direction.

Edging sander and hand scraper. An edging machine is a type of disk sander necessary for reaching areas (next to walls, for ex ample) that can’t be reached with a drum sander. You’ll also need a hand scraper for cleaning out corners and reaching into other tight areas — such as around radiators.

Fig. 98-2

Buffer. A professional floor buffer, the type with a single large revolving pad, is needed to buff the floor with steel wool after the stain and/or sealer have been applied.

Fig. 98-3

Sandpaper. Because three sandings — called “cuts”—are required to remove an old finish, you’ll need three grades of sand paper. Depending on the finish you’re removing, the first sanding should be done with 40-grit to 20-grit paper (the lower the number, the coarser the paper).

A 20-grit paper should be used to remove old paint, or where a floor is particularly rough. A 30-grit paper is about right for removing old shellac or varnish. A 40-grit paper is good for sanding a herringbone or wood block (parquet) floor, or a wood strip floor in good condition.

A 60-grit paper is needed for the second sanding, and 80 or 100-grit paper for the final sanding.

To sand the floor of an average room, about 14 by 16 feet, you’ll need about two sheets of each grade of paper and four edger disks of each grade. Worn paper won’t work as a substitute for a finer grade.

Other helpful supplies. When sanding a floor, you may need a hammer and nailset to drive down protruding nailheads, and wood putty to fill holes, dents, and gouges. Choose putty that will blend with the finish to be used or will take a stain. Professionals use a product called “goop-on” for filling.

Sanding a floor is a very dusty and noisy job. Anyone operating a power sander should wear a mask. Earplugs or ear muffs will help prevent a throbbing head and possible ear damage.

The dust kicked up by sanding manages to escape through unbelievably fine openings, so you’ll want to seal doors to other rooms with masking tape or sheet plastic. Taking such care before sanding will save you a good deal of housecleaning later.

You’ll also want to wear soft sole, non-marring shoes—and make sure that no one walks on your newly sanded floor. With the pores of the wood exposed, an unprotected floor will soil easily.

Sanding a strip or plank floor

As you prepare to get down to the work of sanding your floor, keep in mind that the first coat of the new finish should be applied the same day the sanding is completed. This will prevent moisture in the air from raising the grain in the raw wood, and dirt from marring the exposed floor. So plan your time accordingly.

To prepare the floor for sanding, take up the molding along the baseboards. If you remove the pieces of molding in sequence and number each piece with chalk or a pencil as you go, it will be easier to replace them when the floor has been refinished. Also remove all floor grates, door stops, and any other fixtures. Set any protruding nails below the surface of the floor, and fill the nail holes—and any other dents or gouges that you see — with wood putty. Finally, sweep the floor clear of dirt and debris.

In sanding strip or plank flooring, you’ll always go with the grain—unless you’re faced with an exceptionally rough floor or a floor with cupped boards. In such cases, the first cut (sanding) should be made on the diagonal; otherwise, the procedure is the same.

A floor sander going at full tilt can be an intimidating piece of equipment; handling it is not an easy job. But if you follow a few basic rules, you’ll quickly gain confidence and get the up per hand. Keep in mind that the objective is to take of I the mini mum amount of wood possible while removing all of the old finish.

Making sure that the drum sander is unplugged, begin by loading the drum with the coarse-grade paper you’ve selected (see illustrations on facing page). When the paper is in place, plug in the sander and prepare for the moment of truth.

The first sanding. When you’re ready to make your first pass across the floor, lower the drum slowly and move out, literally, the instant it touches the floor. Do not allow the drum to bite into the floor before beginning to move. If you do, you’ll gouge the floor, leaving a permanent reminder of your error.

The forward rotation of the drum will pull the machine for ward. Keep it in hand and move forward at a steady pace. As you approach the end of your first run, be ready to lift the drum off the floor while the sander is still moving forward. If you try to stop the sander, then lift the drum, you won’t be able to act quickly enough to avoid taking a hunk out of the floor.

When you’ve completed one pass, shift the sander over to be gin the next pass, with the drum overlapping the last cut by 2 or 3 inches. On the return trip, you’ll have to pull the sander back wards; go at the same steady rate.

When you’ve finished sanding as much of the floor as you can with the drum sander, it’s time to load the disk sander with the same coarse-grade sand paper and sand the areas the drum sander was unable to reach. Work on these areas until the disk has removed about the same amount of material as was removed by the drum sander.

When you’ve completed the first sanding, set any protruding nails and fill all nail holes, dents, and gouges.

The second sanding. Load the drum sander with a medium-grade sandpaper and make a second cut over the whole floor. Then, with medium-grade pa per on the disk sander, go over the edges once again.

If after the second sanding you discover exposed nail heads or uncover holes that need filling, set the nail heads and fill all holes with wood putty.

Between the second and final sandings, clean out any spots you were unable to reach with either of the power sanders during the first two sandings. Corners, areas around pipes and radiators, and door jambs have to be scraped by hand. When using a scraper, pull toward you while exerting downward pres sure. If possible, scrape with the grain. Keep a file handy—the scraper should be sharpened frequently to make it an effective tool.

When you’ve scraped away the old finish, wrap medium-grade sandpaper around a block of wood and go over the scraped areas. Finish off with a fine sandpaper of the same grade you plan to use for the final floor sanding.

Fig. 99-0

The final sanding. Using fine-grit sandpaper, go over the entire floor one last time with the drum and disk sanders.

Sanding wood block floors

Wood block flooring—whether of tiles or inlaid wood mosaic—is commonly called parquet, and it comes in a variety of styles and types of wood. The basic directions for sanding a strip or plank floor apply also to a wood block floor. The only difference is that with wood block flooring, all three sandings should be done in a diagonal pattern. This compensates for the fact that the wood grains in these floors run in several different directions.

Make the first pass with the drum sander from one corner of the room diagonally across the room at a 45° angle. The second sanding—the one with medium-grade sandpaper—runs across the other diagonal of the room to produce a crisscross pattern. The final fine sanding follows the direction of the first sanding.

Fig. 100-0

When the final sanding has been completed, clean up the wood dust with a vacuum cleaner. Make a final sweep of the floor with a barely moist mop or, better yet, a tack cloth.

Check the surface carefully for any blemishes that may have escaped notice earlier, and take care of them now. If any nail holes are showing, fill them with wood putty selected to match the final

Cleanup is crucial

When the final sanding has been completed, clean up the wood dust with a vacuum cleaner. Make a final sweep of the floor with a barely moist mop or, better yet, a tack cloth. In disposing of the debris from the dust bags of the power sanders, do not dump the dust directly into a closed garbage can. The dust will be warm and will contain wax and varnish residue—it could catch fire. Allow it to cool before disposing of it in closed containers.

Applying the finish

When you have a perfectly clean and exposed floor under your clean feet, you can go ahead and begin the process of applying the final floor finish.

Remember: the first coat should be applied the same day the final sanding is finished. This will keep the exposed wood from getting dirty and absorbing moisture that may raise the grain.

There’s no general agreement as to which finishing products are best. You can decide whether or not to use a stain, and exactly what type of finishing coat to apply, according to the specific results you want.

Regardless of what products you’ve selected, read through the manufacturer’s directions care fully before applying any finish. It’s wise to test the products you’ve chosen in a closet or out- of-the-way place before applying them to the entire floor.

We found no single preferred procedure for finishing a floor. Among professionals, the method will vary according to the products being used and the person doing the job. What follows is a step-by-step description of one typical procedure. It involves using a stain and then applying either a penetrating sealer or a hard surface finish (the characteristics of the two are different).

Applying a stain. Pour all the stain you’ll be using into a bucket and mix it thoroughly. Dip a clean, dry rag (of lint-free fabric) into the stain and spread it liberally over the floor. Near the walls, apply the stain with a clean brush.

Wait 5 or 10 minutes to allow the stain to penetrate the pores of the wood; then use clean rags to wipe up any excess stain. Let the floor dry overnight.

When the stain has dried, buff the floor with #2 steel wool. Follow this with a particularly thorough vacuuming of the floor. Now the floor’s ready for a coat of either penetrating sealer or hard finish.

Applying a penetrating sealer. In general, a penetrating sealer is a free-flowing liquid that can be applied with a clean rag, brush, or roller. The manufacturers of specific products may have specific recommendations.

Apply sealer liberally, allowing it to flow into the pores of the wood. Stat in a corner or next to a wall to avoid having to walk over wet sealer. After the sealer has had ample time to penetrate (check the manufacturer’s instructions), wipe up any excess with dry rags and let the sealer dry for the length of time recommended by the manufacturer. Drying time may be affected by humidity and temperature.

Decide how many coats of sealer you should apply to a newly refinished wood floor ac cording to the sealer manufacturer’s suggestions and the results you want to achieve.

Applying surface finishes. Typical surface finishes — polyurethane, varnish, lacquer, and shellac — are applied like paint. They produce a surface with a different texture from that left by penetrating sealers.

Polyurethane has become the dominant floor finish used today because it provides a hard, plastic-like finish that is much easier to take care of than other surface finishes.

To apply polyurethane, use a clean brush to put down a coat of finish along the walls and around obstacles. Then use a long-handled paint roller with a mohair roller to apply the finish evenly over the rest of the floor. Work with the grain when possible. Typically, two coats are required. Allow the first coat to dry (follow the manufacturer’s recommendations); then use a floor buffer equipped with #2 steel wool to smooth the surface. Corners and hard-to-reach areas should be smoothed by hand.

Clean the floor thoroughly with a vacuum cleaner. Then go over it with a barely damp mop or rag to pick up fragments of steel wool and dust. Be thorough—any dirt left on the surface will be sealed in when you apply the second coat of polyurethane.

When the floor is clean and dry, apply a second coat of finish, working across the grain when possible.

No longer widely used, varnish, shellac, or lacquer are applied in much the same manner as polyurethane. Check the directions of the manufacturer before applying any of these special finishes.

The “finishing” touches. Allow the floor sufficient time to dry—plan on about 72 hours—then replace the molding, grates, and other fixtures that were removed.

If you’ve used a penetrating sealer, the floor will require waxing. Select a wax made for floors, and follow the manufacturer’s recommendations for applying it. Polyurethane is sold as a finish that needs no wax, but many homeowners prefer the look obtained by applying a coat of wax.

For additional information on caring for your newly finished floor, see “Caring for a Wood Floor”.

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Saturday, 2008-12-13 20:06