Sanding, screening, and finishing: Refinishing Wood Floors

Although oak wood is a durable material, its surface finish determines how good it looks.

Old hardwood floors: What can you do to make them look new again?

If your floor has water stains, scratches, dullness, or whole areas worn bare by household traffic, it’s time to refinish it. This used to require sanding down to bare wood, a dusty, time-consuming process that can be risky if you don’t have the right experience or expensive if you hire a professional. Many floors can be revitalized by screening, but some require this level of work.

How Does Hardwood Floor Screening Work?

Polyurethane is removed with screening, but wood is not removed. Using this relatively inexpensive technique, you can do the work yourself without much risk and avoid the hassle and cleanup associated with floor sanding

Use a 16-inch tool to make overlapping passes. This floor polisher is equipped with 60-, 80-, 100-, and 120-grit screens. Using a 100-grit sandpaper palm sander, sand screen edges by hand. Andrew Kline took the photo

A wood floor can be recoated and screened in a few simple steps.

Sanding disks that are clog-resistant are called screens. An oscillating floor polisher, which measures 16 inches, is used to screen. A drum sander will take off on you, but this one doesn’t. A synthetic-wool pad and the weight of the floor polisher hold the screen in place.

The purpose of screening is to remove the floor finish without cutting into the wood itself, so you should:

Waxed polyurethane floors cannot be screened.

• Use a polyurethane finish on the screen, which sits on top of the floor without penetrating it.
• The wood underneath must not be stained or damaged if the finish is worn, scratched or dull.

What is the cost of screening?

A rental unit costs around $25 per day if you decide to do it yourself. These disks cost between $6 and $10 each, ranging from 60 to 120 grit. Hire a professional floor refinisher if you don’t have the time to do the work yourself or don’t want to deal with that much dust. If the floor needs one or two coats of finish, the cost will range from 90 cents to $1.50 per square foot.

Prior to attaching the screening disk to the machine, use grit sandpaper to remove the rough burrs. Using this method prevents the polished finish from being cut too deeply when the machine is first started. Andrew Kline took the photo

Screening Before You Begin

• Furniture, carpets, and paintings that collect dust should be removed from the room as soon as possible.
• All doorways should be sealed off with plastic sheeting and masking tape, duct registers should be sealed off with plastic, and cabinet doors should be taped shut.
• Place a fan in one of the windows to blow out dust if the weather permits. If you are wearing a respirator, wear it with or without a fan.
• Removing the quarter-round molding along the baseboard and countersinking any flooring nails that stick out should be done temporarily.

Hardwood Floor Screening Tips

1. With a palm sander loaded with 100-grit sandpaper, take the edge off the screen before attaching it. The first time the polisher is used, any high spots on the disk are knocked down so they won’t dig into the finish too deeply.
2. Floor polishers and screens will be used to screen most of the floor. From rough to smooth, use four grits of screening (60-, 80-, 100- and 120-grit). Sanding pads or palm sanders fitted with sandpaper can be used for corners and edges.
3. After you have completed all of your work, sweep walls and vacuum all surfaces to remove dust.
4. To remove remaining floor dust, use a 4-square-foot tack cloth made from cheesecloth ($2) that’s been treated. Sawdust can spontaneously burn, so bag it and leave it outside.

Does polyurethane require sanding?

Floors with wax finishes over polyurethane, finishes that have worn through, or floors that are stained or damaged should be sanded down to bare wood.

Sand your floors before you start

Screening requires the same preparations, although you may need to create a double airlock (plastic on both sides of a door) to contain the dust.

It’s also worth considering whether you want to do the work yourself, especially if it’s a large open area where unevenness in the floor will be apparent.

When operated by an inexperienced person, drum sanders can dig into the floor very quickly, leaving unsightly gouges. In addition to finish application and cleanup, a professional will charge $1.50 to $3 per square foot. Make sure you watch a how-to video before starting the work (try a rental store or the local library).

Sanding floors yourself costs how much?

For around $55 a day, you can rent a drum sander and edger to do the main floor. Both devices can’t reach corners, so you’ll have to use a razor-sharp floor scraper to clean them.