I am facing this same issue right now! I have red paint over top of yellow paint over top of original 200 year old wood floors. I wish I had a magical answer for you. The paint DOES come off, but it takes some doing. I'm using a combination of chemical stripper, heat gun and sander (not all at the same time!)

I'm considering calling a professional....I'm sure what will conceivably take me the rest of my life is a job they could take care of in a matter of a day or two..lol!

Here is what I am dealing with.... this is my staircase...

Good luck, and have patience!!

A professional sanding by someone who knows old floors is worth seeking out. It may take longer than you think though because there may be surprises under the paint such as cupping (? I think this is the correct term when board edges curl upward). My floors appeared relatively flat & level until the sanding started; then it became perfectly obvious that paint was the leveling agent. The floor guy had allocated a weekend to do 2 large rooms - in the end, he totalled about 40 hours!

It was some of the best money I've ever spent!

I know that docks and probably DECKS too, are built with the cup of the wood grain turned down, unless it is the real choice edge grain. If you look at the end of a board and see tat it was installed such that the wood grains turn UP like a BOWL, then it will over time tend to "cup."

The wood is installed to turn the "cup" downward so it will not puddle, but will instead allow water to drain away. I'm not sure how this figures into a set of interior stairs, but it sounds like the same rule would apply.

Hmmm, what kind of hardwood do you have?

Not to hijack the thread...but.......Hubby and I recently uncovered the wood beneath our foyer linoleum, and at the time, I made a comment regarding the 200 year old floors having the cupping and that they did not make sure the grain of the wood was arched downwards...we have a pretty fair amount of cupping. I can't imagine sanding the cupping away to the point of smoothness...it seems like that would remove a good bit of the surface of the wood, potentially exposing the tongue and groove???? How would a situation like that be dealt with regarding the sanding process?

Mocassin, I think the wood upstairs I'm talking about is some sort of Oak. (The wood that is painted). My partner thinks we should just paint over the white a nice reddish brown and worry about refinishing it/sanding it when we have more money. I'm not sure about that.

Which brings me to another curious issue - the hardwood downstairs! We can't figure out what it is! It's super hard and a reddish color when the varnish/stain is off of it. It can't be Oak. The grain is similar to oak in that it is not wide grained but.

I'm thinking maybe it's an exotic wood or something I don't know. It's harder than any wood I've ever experience. I can get a pic if it helps but it probably wouldn't.

Our old house had painted floors

in mustard:
{{!gwi}}
in cream:
{{!gwi}}
in green:
{{!gwi}}

We decided to repaint the cream and mustard floors to something we liked better, and deal with refinishing them later. A professional painter friend did the work, and it nearly drove him mad. Whatever paint the PO used, it took 4 coats to get coverage, the old paint kept showing through.

Finally, the floors looked nice so we let them cure for 12+ hours, then moved in minimal furniture (it had to go somewhere!), and let them cure another 24 hours before we moved anything else in or started using those two rooms. Some paint has come up on the rubber feet of my sewing machine (it was set on the floor a full week after final painting), some has chipped off in the moving of things. Where our paint has come up, it has taken up the PO's paint too and I can see the original floor finish --and it's beautiful.

So right now, I'm PO'd with the POs and wished we'd just refinished :-P Live and learn--we're going to leave the green floor strictly alone for now.

"I'm not sure how this figures into a set of interior stairs, but it sounds like the same rule would apply. "

Wood flooring in a house should never see enough changes in moisture content to cup significantly.

It can show up when the wood floor is flooded with water, but tincture of time will restore it to the original shape.

Chapter 3 of the USDA Wood Handbook (linked below) covers "Physical Properties and Moisture Relations of Wood."

Figure 3-3 shows how the shape of various pieces of wood cuts of wood change shape with changes in moisture content and where they were originally located in a log.

Placing outdoor wood 'bark up' or 'bark down' only works if you have an idea of the present moisture content of the wood, and what the final level will be.

Here is a link that might be useful: USDA Wood Handbook, Chapter 3

Hey Krycek, if the wood looks similar to oak, what would you say to it being red oak? I'd think that is more likely than something exotic since your house is around the same age as mine and similar in style...mine is actually two years older, now that I think of it. :)
Downstairs I have white oak floors and my trim is red oak, upstairs, same trim but floors are a type of pine.