How to Remove Polyurethane From a Hardwood Floor Without Damaging It

Before refinishing your hardwood floor, first remove the old polyurethane.

Because new hardwood floors can be so expensive, you may choose to refinish your existing hardwood flooring. Sanding a hardwood floor to remove polyurethane means buying or renting a floor sander and investing time, but the process pays off when your old polyurethane finish is gone, paving the way for gorgeous refinished floors.

Things You'll Need

• Utility knife
• 3 pry bars
• Vacuum
• Floor sander
• Sandpaper discs, 36-grit, 50-grit and 80-grit
• Cloth
• Mineral spirits

Instructions

1. Score the seal between the painted wall and trim or baseboard with a utility knife to begin removal of the baseboard and trim.

2. Wedge the end of a pry bar between the baseboard or trim and the wall. Gently nudge it outward slightly and leave it in place. Move down the wall several feet and place the end of another pry bar between the baseboard or trim and wall. Nudge it outward as well, then place a third pry bar in the same manner yet a few more feet beyond that.

3. Pull the trim or baseboard away from the wall carefully and, as you free each portion from the wall, move the pry bars down the wall, continuing the process. This allows for a more gradual pulling away of the trim, rather than taking the chance of pulling it away too drastically and breaking the material.

4. Vacuum the floor to ensure no large pieces of wood or debris are present to gouge the hardwood floor during sanding.

5. Attach 36-grit sandpaper discs to an orbital floor sander following the sander manufacturer's directions.

6. Place the sander in one corner of the room and turn it on. Proceed to sand the floor, moving from one end of the room to the other in sections. This process will take a long time if your floor is particularly uneven or damaged, so be patient as you sand. You may have to make multiple passes over each section to successfully remove the polyurethane finish.

7. Vacuum any remaining dust and sandpaper grit from the floor. The sander should have an internal vacuum, but it may miss pieces of debris, and you want to be sure all potential scratches are prevented.

8. Replace the 36-grit sandpaper discs with 50-grit discs. Sand the floor evenly with the finer-grain discs, then vacuum once again before applying 80-grain discs and sanding the entire floor with them. Vacuum again.

9. Apply mineral spirits to a rag and wipe the floor thoroughly to remove any remaining dust.

Tips & Warnings

• Sand any missed areas around the edges of the room with a hand-held sander.

References

• Hammer Zone: Sanding Hardwood Floors and Applying Polyurethane
• This Old House: How to Refinish Hardwood Floors