How to Repair Rotted Wood Floors

If an area in your wood floor has rotted, it should be replaced promptly. Not only does a rotting floor represent a safety hazard, but rot can spread to the surrounding floor and underlying structure members.

Step 1: Locate all of the rotted areas of flooring. Mark their location using painter's tape. You should plan on removing whole boards when repairing rot, even when only a partial board is affected.

Step 2: Use a circular saw, set to the depth of the flooring only, to remove the damaged boards. Saw from the center of the board, being careful not to cut off the edges of the boards, which may have a tongue and groove joining.

Step 3: Knock out the center of the boards with a wood chisel and hammer. Also use the chisel to remove the edges of the rotted boards, being careful not to damage the surrounding joinery.

TIP: You may find that the wood floors are not fastened with tongue and groove. If this is the case, you may be able to use a pry bar to lift the boards affected by rot and forgo use of a chisel.

Step 4: Examine the underlying structure of the floor. If the sub floor is affected, you must remove the damaged patches. If the joists are rotted, you should get the opinion of an engineer to determine the safety of the house, then replace the joists. If the underlying structure is sound, you may proceed.

Step 5: Remove any fasteners embedded in the joists or sub floor.

Step 6: Cut a replacement wood board to the appropriate length. If the boards in your wood floor are tongue and groove, you should cut off the bottom lip that forms the complete groove of the board.

Step 7: Slide the wood board into place. For tongue and groove boards, stick the tongue of the new board into the appropriate groove, then use a rubber mallet to tap the board completely into place.

Step 8: Use finishing nails to secure the boards to the underlying sub floor or joists.

Step 9: Stain, seal, and paint as necessary to have the new boards match the old wood floor.