How to Replace a Floorboard
Although the tongue-and-groove joints that unite the boards in a wood floor may seem to preclude replacing just one board, the process is pretty straightforward. Since the board to be replaced is toast anyway, removing it piecemeal makes that part of the process simple. Then it’s a matter of removing the lip that forms the bottom of the replacement board’s groove so it will fit over the tongue of the existing flooring. The new board is then fit in place and secured with glue. This type of repair is usually part of a floor refinishing project because the new board has to be sanded even with the surrounding boards and finished to match.
You might think that finding a replacement board would simply entail visiting a lumberyard and buying one. It’s rarely that simple, though. Even common 3/4-in. by 2-1/4-in. red oak is sold in 20-sq.-ft. bundles for about $2 per sq. ft. If your flooring is anything other than 2-1/4-in. red oak, you’ll probably have to buy it from a specialty supplier or have a piece milled.
If you’re lucky, though, you may have a solution at hand. The original builder may have left a few pieces of flooring up in the attic. It’s worth a look, but if you aren’t that lucky, don’t give up. Odds are you can carefully remove a piece from inside a closet. Choose one from the edge so that you can get it out without having to split it in half, then replace it with whatever flooring you can scrounge or make.
Watch where you make that cut
Careful installers pay attention to where they place the joints in a floor. A few things to avoid are butt joints closer than 6 in. to each other, evenly spaced joints that resemble stair steps, and patterns where three joints in consecutive rows resemble the letter H. When replacing a board, be careful to avoid creating one of these situations. A good rule of thumb is to not have any joints that are closer than the width of a floorboard over three neighboring courses.
Photos: Justin Fink
Cut long boards. Remove a damaged short board entirely. With longer boards, it’s less work just to remove 1 ft. or so of a bad section. Mark a square line across the board, and chisel a series of cuts about 1/4 in. into the board.
Chop out the waste. Chiseling the damaged board toward the initial square cut, remove 1/4 in. of wood at a time. Repeat these first two steps until you’ve cut all the way through the board. You also can make the cut with a multitool.
Split the bad board. Drive in the chisel parallel to the grain in several places. When the board splits, lever out the chunks with the chisel.
Vacuum out the debris. If there’s a layer of tar paper or rosin paper below the flooring, remove it to expose the subfloor before vacuuming up wood debris.
Break the bottom of the groove. Lay the replacement board on a clean section of floor, and use a hammer to break the bottom lip that forms the groove.
Remove the bottom lip. Clean up the broken edge with a knife or plane to ensure that the new board fits over the tongue of the abutting flooring.
Construction adhesive seals the deal. Put two beads of adhesive on the subfloor, and another along the tongue of the abutting board. Leave the other edge unglued to allow for seasonal movement.
Slip in the replacement board. Engage the replacement board’s tongue with the abutting groove, and push the groove edge down.
Tap it home. Strike the replacement board with a heavy hammer, being sure that the hammer face hits squarely to minimize marring. If the board doesn’t seat well, drive a couple of 6d finish nails into it to hold it down.
Closely spaced joints