I have a 60 year old house and the original hardwood floors have been covered for at least 25 years and the slats are cupped with the edges of each slat being higher than the center of the slat. What is the best way to sand these floors smooth so that i may put either another layer of hard woods or vinyl slats over the top of these existing floors?

3 Answers 3


Worst case scenario: remove the flooring.

Medium damage throughout: Lay down 3/8" plywood over it, first replacing heavily damaged areas.

Every board is slightly cupped: Have it professionally sanded and refinished. Upright floor sanders can be rented but they are not for novices. A random orbit sander would get it done... eventually.

  • 2
    Just to confirm what Mazura recommends. The floors can be checked if they can take another sanding which I am sure they can. As far as floors go, they are not that old. Commercial floor sanders can take that down with no problem, and what is said about random orbit is true too. It would be a shame to cover them up with vinyl or some other product. That's all I really wanted to add. Refinishing is all it needs, they will be dazzling.
    – Jack
    Oct 27, 2014 at 3:55
  • I visited a house with beautiful floors. I offered a compliment and asked whether they had installed them (since I was in the middle of my own installation project). They said no, they were original to the old (for Seattle) house, and were in terrible condition until they hired someone to re-sand and refinish them. "Dazzling" is a suitable description.
    – Steve
    Nov 9, 2017 at 22:34

You might consider removing the slats and replacing them with sheets of plywood - it's likely to be less work than anything else you will do.

You could use steam to soften the wood, and nail the edges, but that's a ton of work.

You could try a huge floor sander, but they are not made for removing that much wood, and you will be left with very weak slats.

I would remove them, it's less work than the alternatives.


Cupped floorboards are generally caused by water damage. If the cupping is slight, you can sand it with a commercial sander.

If they are too far gone, then it might be better to remove the wood and replace it instead of going over the top of it. If you add another layer to it, then it would throw off the height of the thresholds, doors, moldings, etc.

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