You may think that when a polyurethane or varnish finish on a hardwood floor becomes dull, scratched and worn, your only recourse is to call in a professional to sand the floors down to the bare wood and refinish. But there's a simpler approach, well within the capabilities of a do-it-yourselfer--the screen-and-overcoat technique. If your wood floors are prefinished, consult the manufacturer for safety and finish recommendations.
Move all furniture and wall decorations out of the room.
Install a box fan in a window within the room, and open a window across the room and just outside the room. With the fan set to exhaust, the negative pressure keeps dust from moving outside the room.
Just in case, cover furniture in adjoining rooms with lightweight plastic drop cloths.
Install an abrasive pad on the rubberized wheel of a floor polisher to practice in the center of the room until you are comfortable controlling the machine.
Install a 100-grit abrasive screen on the polisher and sand the floor. Go back and forth across the floor in overlapping passes from one end of the room to the other.
Sweep, vacuum and inspect the floor. All the finish should be dull, wear patterns should no longer be noticeable, and any scratches and stains should be gone. Repeat the sanding as necessary.
Using a random-orbit electric sander, sand areas at the perimeter where the polisher missed. Use a rubber sanding block with fine sandpaper (or a sanding sponge), sanding with the grain, on areas the sander couldn't reach.
Sweep, vacuum, dust and then vacuum again to clean the room (floors, walls, baseboards) and eliminate all dust.
Using a soft cloth slightly dampened with mineral spirits, wipe down the entire floor, turning and shaking out the cloth often.
Turn the fan off and vacuum one final time, using the floor brush on large areas and the pointed wand at the perimeter and in cracks.
Using a professional-quality angled sash brush, cut in a band of finish 3 inches (7.5 cm) wide along the baseboard on one wall and about 2 feet (60 cm) down the sides.
Using a professional-quality varnish brush 5 inches (13 cm) wide, apply an even coat of finish. Work across the room, following the direction of the flooring planks, coating about a 2-foot (60-cm) strip at a time. Cut in more along the walls as needed.
In your kitchen, place small, washable area rugs in front of the stove, sink and refrigerator. Heavy traffic, spills and dropped items will be less likely to damage the floor.
Wipe up spills immediately with a dry cloth or paper towel. Use a slightly damp mop or cloth, if necessary, but dry the floor immediately after.
Keep dirt, especially gritty sand, out of the house. Choose exterior mats that are most effective at removing dirt, and add throw rugs inside to catch any remaining dirt. Regularly shake out, hose off or otherwise clean the mats and area rugs.
Set up a convenient place for people to slip off dirty or wet shoes just inside the most commonly used family entrance.
Acknowledge that you can't keep all dirt out. Vacuum often to remove dirt that slips by your defenses.
Protect wood floors from excessive sunlight, which can cause colors to fade or finishes to fail. Exterior awnings, drapes, window tinting or area rugs may all be helpful solutions.
Install and frequently clean fabric glides on chairs, tables and other furniture legs. Pay special attention to clean or vacuum the glides on chairs often, and replace them about once a year, depending on use.