Thank you for your response! I'm not sure how to determine the amount of meat there is.. the home is heated with a boiler/radiators. Is there another way to find out?

Can you fit a measure in where the pipes for your rads come up through the floor?

There are often transition strips or t-moldings between different floor finishes...like where the wood meets tile, stone, lino, etc. Sometimes a door 'saddle' can be removed to view the cross section. If you can access the basement/crawlspace, you can look 'up' to see what type of subfloor you have...but that won't help you with the floor thickness.

If you have an inspection by a local floor contractor that will also be beneficial. Original Fir floors would be gorgeous if refinished.

The first floor looks to be a strip floor, not tongue and groove. Very common at the time, and very thin--probably only 1/4". Looks really nice and appropriate to the period (but I bet it squeaks like the devil when you walk on it).

Never heard of a floor that old that’s only 1/4” thick

km kane: That kind of flooring from turn-of-the-century was very common and it was thin and flexible and face nailed (generally 2 nails per board at every joist). I doubt there were many standards back then. The strips were usually 1 1/2" or 2" wide and 1/4" to 3/8" thick--5/16" seems to have been common too. More like lath than real boards.

Do a search for oak strip flooring face-nailed. Lots of info. Unfortunately, just searching for strip flooring mostly return returns examples of how to strip floors.

Tatts, very interesting. I‘ve lived in two areas of the country (old east and far north west) where wood floors were common, and never knew of any that were only 1/4” thick. They were, and had to be, at least 3/4“ thick, with a wood slat sub-floor, to support the weight. In these houses with just 1/4” thick boards, how did the joists work? What was the subfloor? I’d love to know where this was the norm! Thanks for the info :)

At the turn of the century, it was not uncommon to have a finished floor perimeter with the expectation that a rug would cover the raw floor in the center.

Quick update.. we removed the carpet in the upstairs. After much time prepping the wood and removing what felt like millions of staples, we sanded and refinished the floors. I know most would not recommend this as a DIY project but it was the most reasonable option we had. The floor is NOT perfect, weathered and worn over the 111 years it's been lived on. I am happy with the result.

Kudos to you, I think it's gorgeous!

Beautiful! I love floors with character, and these have that but are also very nice looking. Congrats on a good find!

You must be thrilled! Looks great.

Very nice! Back to your original question, your wood is most likely floor AND subfloor. It's probably flooring laid right on the joists. That's why you have end joints that line up across the floor at regular intervals (often multiples of 16" or 24"). The ends of the boards are laid on joists.

Gorgeous result!!!

thanks everyone! Now to plan my next project

Looks Great! Great job on the sanding and finishing. Your floors can put a lot pros to shame.

Love it ...much nicer the new wood floors