Looks like Parquet to me Google it.

That is the subfloor that you are seeing in the grate. With parquet on top.

Sophie's on it! The lowest level (the tongue and groove stuff that looks to be 1/2" thick or so) is the subfloor. Not harwdood. Subfloor. These are "planked subfloors". The thin "wood like" substance on top = the parquet (the wood patterned floor lurking under the carpet).

So you have old (thin) parquet sitting on top of old, thick planked (tongue and groove) subfloor planks. Things are looking a little wavy. Parts of the parquet look to be coming loose (at least near the grate). I would say they threw down some carpet to hide the "beat up" parquet. Of course they look great in low traffic areas (like by a wall) but the wear areas would probably be in bad shape.

I don't think you have enough "meat" on the parquet to salvage it if you remove the carpet. It would most likely have to come off or a new 1/2" plywood laid over it and start again. The tongue and groove subfloor was never meant to be "finished". It requires something over top. There is nothing to salvage as it is not "flooring".

The only way to know for sure = remove all the carpet.

Thanks for the comments, all.

Cancork, you gave alot of insight... however - we do have a diagonal subfloor underneath the tongue and groove that can be seen from the crawlspace. So do we have 2 layers of sub-floor?

Good question...A local guy who has seen dozens of these things can help you. Even if you have 2 layers of subfloor, there isn't much on the market that is allowed over top of "planked subflooring"...other than carpet.

At this point in time, it is time to get a professional flooring installer (NWFA Certification is a great help...'coz they know SO MUCH MORE than "Chuck in a Truck") to come in and have a look throughout the home to see what you have.