Refinishing Hardwood Floors

Refinishing hardwood floors is not a difficult job, but you do need some experience working with power tools and enough patience to be thorough. If you have an older home and the hardwood floors have been under carpeting for a decade or three, you will find that they will have a depth and character not seen in newer hardwood flooring. It is worth the mess and work to restore them, as they can add significantly to the charm and value of your home.

Tools Required
Shop vacuum
Plastic sheeting
Masking tape
Drum sander
Edge sander
Palm sander
Paint applicators
Ear protection
Respirator
Stain
Varnish
Sealer
Old towels and rags

Preparing the Room
Remove everything from the room, including window coverings and blinds. Even with a dust collecting bag on the sander, you will still create a lot of sanding dust. For this reason, tape sheets of plastic over openings and doorways wherever it is practical to do so. Remove vent face plates and seal those with plastic or old towels to prevent dust getting sucked into your ductwork.

There is no need to remove the baseboards, but you will probably want to replace the quarter round shoe molding. Decide whether you want it to match the floor stain or painted baseboards. Whichever route you decide upon, get enough to go around the room and finish or paint it before installing it.

Check your floors for nailheads above the surface and staples from carpet padding, since these will tear expensive pieces of sandpaper immediately. If there are any loose or defective boards, now is the time to replace them. This can get tricky, because it's almost impossible to match new flooring to older flooring and you may encounter variations in thickness or width with newer flooring materials. If you're dealing with outdated flooring and you simply must attempt to match it, look for a lumber yard in your area that can custom mill pieces of wood to replace the damaged boards. This can be expensive, but you'll get the best results.

Don't try to fill all the cracks. You can leave all the joints unfilled, or just fill the especially wide ones. If you plan on staining the floor, use wood putty that will accept a stain. If you are going to leave the floors natural, choose a filler that will best match the finished wood.

Vacuum the floor thoroughly before you start, and each time you switch to a finer grit sandpaper.

Sanding Hardwood Floors
You will probably need to rent at least the drum sander and the edge sander. Ask the rental yard for instructions on how to use these tools so you don't make gouges and scratched swirls in the wood. Ear protection is a good idea because the sanders are incredibly noisy. Use an OSHA approved respirator, especially if the floors are older, to avoid breathing in lead dust.

The rental yard will have the sandpaper you need. Give them the rough dimensions of the room so they know how much of each grit to sell you. If the floors have a lot of built up varnish, you may need to start with 20-grit paper. Otherwise, using 60 grit for your first pass will remove most of the old finish. You will finish up with 120-grit paper.

The drum sander works very quickly and efficiently. To get a feel for it, start in a usually covered part of the floor or an inconspicuous area. Never stop the machine without lifting the drum from the floor first, because it takes just seconds to gouge the wood. Always move the machine in the direction of the floor's grain.

Do as much area as you can with the floor sander. Use an edging sander and the palm sander along the edges and in corners. If the floor is not in terrible shape, you may be able to do all the edges with your palm sander, switching from heavy- to fine-grit sandpaper as you go. If there are many layers of old finish to get up, it will be worth your while to rent a more powerful edging sander.

Staining the Floor
You'll probably want to stain your floor before finishing it. The most common combination is an oil-based stain, followed by several coats of acrylic (water-based) varnish. There are also water-based and gel-type stains, but many refinishers find that they do not give the depth and richness of color that an oil stain creates.

Try to stain on a day when you can open windows and get some fans going to control the fumes. Work as quickly as you can to prevent the stain from setting up too fast. It's often helpful to have two people: one applying the stain liberally and the other following behind with rags or old towels to wipe down the excess. Don't use rags that will shed lint. You can buy boxes of rags from your flooring supply outlet. Work with the grain of the wood and stand back frequently to check for areas you missed.

Follow the directions on the can for drying time. This will usually be overnight. Don't let anyone walk on the floor while it is drying.

Finishing Your Floor
You can use oil-based polyurethane varnish or water-based urethane. The water-based products are very durable, dry faster and don't smell nearly as bad. A disadvantage is that they are thinner than oil-based products and may require an extra coat. You can often do two coats in one day with good drying conditions.

The only other disadvantage to using water-based urethane finishes is that the water in the product will raise the grain of the wood on the first-coat application. This means you will need to lightly sand the floor and clean up all sanding debris very carefully between the first and second coats. If you want to avoid doing this, ask your supplier about alcohol-based clear sealers. Used as the first coat over the stain, these will not raise the grain.

Use best quality applicators: natural bristle and rollers for oil-based products and synthetic for water-based urethane. Do the edges first. Always work with the grain of the wood. Do not attempt to do the whole width of the room at a time. Instead, work in three- to four-foot sections using one of the floorboards as a natural break point to avoid brush or roller marks.

With an oil-based finish, you may be able to finish the job with two coats if you are skillful. A water based finish will take you a minimum of three and possibly four coats, depending how careful you are about laying on an even, flowing coat. Water-based urethane can take days to fully cure, so it is best to wait about three days before putting rugs and furniture back on your newly refinished floor, even though it will be safe to walk on it within hours.

Once the floor is done, the last step is attaching your new shoe molding.