Tile is likely out.

Would LVP survive a 1st and second floor that are NOT completely flat? Am I stuck with carpet in this house?

100 yo house? Would you possibly have hardwood floors under that carpet? Seems likely. If so, I would consider planing/sanding & refinish, making them flat in the process.

Check with your local tool rental to see what they have that will grind down the high spots on your old floor.

Look up the installation specs for whatever flooring you are looking at. Those specs will say how flat subfloor needs to be. Filling the low spots is generally easier than sanding the high spots.

The new layer will only be as good as the one below it.

The idea to check the flooring below the carpet is a good one, many years back people put carpet down vs the old flooring, if it's good (the sub floor) you can refinish it and put down nice rugs.

If the floor is going to need a lot of work to get flat and it's not one you can refurbish, you'd be best to put down a new substrate to get a smooth level finish.

Otherwise, Carpet and a really good pad.

I had an old farmhouse with wavy floors and lvp worked great. I rented out to a family with 4 teenagers and a dog. Bought at Home Depot medium price range.

Do you have hardwood? If so, have it professionally refinished.

My first house was built in the 1930's. We had several layers of linoleum we stripped and then had the original hardwood refinished. It was white oak and beyond gorgeous with patterns no one today would take the time to install.

My current house was built in 1962. I did the same thing - removed the old carpet and linoleum. It had beautiful mix of white and red oak underneath we had refinished.

See what is under whatever is there. Chances are a beautiful floor is underneath waiting for you to rescue it.

This message has been edited. Last edited by: KevH,

Yes if you go with a premium underlayment. I agree with everyone else and first see what's under there and if real hardwood just have it refinished.