How to Sand and Repair Hardwood Floors

As homeowners look for ways to spruce up their dwellings, some of them are wondering how to sand and repair hardwood floors. Sanding and/or repairing a hardwood floor is a time-consuming and laborious task that most people elect to have done by a professional. While the task involves considerable effort and some expense, it is not beyond the capability of most do-it-yourselfers. The end results are gratifying, and can significantly improve the visual appeal of any room.

Required tools

Before you begin sanding your hardwood floor, you will need a floor drum sander, an edging or orbital sander, and a buffer with a 150-grit pad (these can be rented). You will also need several grit ratings of sandpaper for both sanding machines, ranging from coarse (36-grit) to fine (100-grit). Next, you're going to need paint thinner, varnish and whatever (if any) stain that you're going to want to apply to the hardwood floor once it has been completely stripped and sanded smooth. If you don't have any at home, some Visqueen and painter's tape or masking tape will also come in handy.

Preparation

The first step in sanding and/or repairing a hardwood floor is to remove everything from the room. This includes all furniture, floor coverings, anything hanging on the walls, and all draperies or curtains. Despite the fact that the drum sander has a vacuum and vacuum collection bag on it, the sanding process can generate considerable dust. It makes quite a mess. The second step involves covering and taping heating and cooling ducts, and all doorways except the one you're using to get materials in and out. You're going to seal that off just prior to starting the sanding process.

Once everything is sealed off, closely inspect the floor for anything that may be protruding above the surface, such as carpet tacks, staples or nail heads. If the sandpaper on the drum sander makes contact with any of these things, it could rip the sandpaper. Remove any base boards or moldings that may be in the way.

Sanding the floor

Starting with 36-grit sandpaper on the drum sander, turn the machine on, and push and/or pull the sander with the direction of the wood grain, never against it. Move the sander in long, moderately slow, even strokes. Keep the sander moving as long as it is turned on; hesitating or pausing for even just a few seconds can cause the sander to gouge into the flooring. If the floor is gouged, it will take several passes with the sander to level it back out.

Once the entire floor has been sanded, including the edges (same grit, orbital sander), change the sandpaper to the next-finest grit and repeat the process. Progress from coarsest to finest -- usually 36-grit, 60-grit, 80-grit, and finally 100-grit sandpaper. When you have progressed through all the steps, the hardwood flooring should be glassy smooth to the touch.

Hardwood floor repair

After sanding, you can remove any boards that need to be replaced. If you are replacing boards, because the boards lock together in a tongue-and-groove fashion, your best bet is to pry a board up at the nearest corner and work your way towards the damaged board(s). If the damage is in the center of the floor, you may opt to cut them out using a circular or radial saw along the length of the damaged area, scoring the ends with a razor knife, and then chiseling out the damaged board ends. When you go to trim the replacement board, you're going to have to trim off a portion of one grooved side so that it can fall tightly into place. Take the damaged board to your lumber yard or lumber supplier to match as closely as possible the type of wood and the grain pattern.

Cut the replacement boards, put them snugly in place and nail the boards in permanently. Make sure you countersink the nail heads below the surface, and fill the indentation with appropriately colored wood putty. Resand the replacement boards and immediate surrounding boards. The floor is now ready to be vacuumed, wiped down and stained or sealed.