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How to Remove a Burn Mark from a Hardwood Floor

Ask This Old House carpenter Nathan Gilbert travels to Portland, Oregon to repair an original wood floor that was burned by a face-down hot iron.


  1. Start by sanding down the area around the burn mark in the direction of the grain using 150-grit sandpaper until bare wood is visible again and the burn mark disappears. Sand a decent area around the burn mark to ensure that the floor doesn’t end up being too deep in the one area just around the mark.
  2. Switch to 180-grit sandpaper and repeat the process.
  3. Grab the sanding block and fine tune the area sanded with a piece of 220-grit sandpaper.
  4. Clean the area with a tack cloth until it’s completely dust free.
  5. Pour the polyurethane into a paint bucket. Gently apply the polyurethane to the floor using a paintbrush. Start in the middle and feather it out as you work toward the edges of the sanded floor.
  6. Let the polyurethane dry for an hour and give the floor another light sanding with the 220-grit sandpaper.
  7. Wipe the additional dust down with the tack cloth and then apply the second coat of polyurethane.
  8. Repeat this process for the third coat.


To repair a burn mark in the floor, Nathan recommends sanding down the floor past the burn mark and then refinishing the floor. If the floor has any stain on it, it may be difficult to match to the original.

In this case, Nathan was able to sand down the floors using a Rotex 90 random orbital sander, manufactured by Festool. He did a few wide passes using 150-, 180-, and 220-grit sandpaper. Between passes, Nathan used tack cloth to remove any sawdust that wasn’t picked up by the vacuum. These can be found at home centers.

For the finish, Nathan used a Varathane clear water-based polyurethane in a semi-gloss finish, which is manufactured by Rust-Oleum.

The other materials Nathan used for the project, including the paintbrush and the paint bucket, can be found at home centers.

Expert assistance with this segment was provided by Nathan Gilbert Carpentry.