Are you sure that's baseboard - it looks like door/window trim.

You know, now I'm not sure bc I didn't purchase it myself. I need to ask...

You want to look at 'L' shaped edge trim.

FLOTROAKEDG24.jpg (960×960) (dgheath.co.uk)

Here's a link to a photo of what I'm talking about (ignore the UK address...it's the idea/shape you are interested in). Your wood manufacturer should have a version of this...or a Window, Door and moulding place should have something in a raw wood. If you pay them enough, they will get you a stain that matches your wood. This is pretty standard stuff for any moulding manufacturer. They will have oodles of things for you to look at.

Yep, what you are using and calling baseboard is actually Colonial Casing. Casing is typically 11/16" thick while base trim is 9/16" for this exact reason. I'll let others answer the transition strip question.

@millworkman thanks for clarifying, can we still use it as a baseboard or would you purchase actual baseboards?

@SJ McCarthy thanks!! I will look into this L-edge transition strip. Since we didn't leave enough room for this type of transition strip, is it ok if we cut the wood that is already installed over the underlayment/plywood, without removing it? I don't want to go through the hassle of taking it out and installing the wood all over again. If so, what kind of tools do you recommend?

Get the narrowest edge transition possible. They can get VERY thin. The image you are looking at has an edge (that goes up against the wall) of less than 1/2". Get the wood edge FIRST and then make it work.

As for the tool, you want a floor cutter. She's an expensive one...so be sure you are going to be using it for DECADES to come. It ain't cheap. And it might not be at your local 'tool share shed'...it is very specialized.

@SJ McCarthy , just wondering, do you think something like a Dremel Multi-tool could also saw a pre-existing wood floor? The wood floor is 1/2 inch thick, and I want to be able to control it enough to avoid accidentally sawing the plywood subfloor underneath it.

The answer is: How do YOU feel about a finish that is torn up to the point where it might cause slivers that run longer than the piece that hides the cut?

The floor cutting tool has a depth 'foot' that prevents you from damaging the blade and/or subfloor underneath.

You may be able to rent a floor cutting tool, or even have someone that has one come and cut, that small area in front of the doors that you have. I do know people that have used a dremel, and have done a good job, but, you have to know exactly how to use that dremel, and it takes a special blade, and they are not cheap. By the time you buy the blade, and go through all the hassle of trying to cut it, the guy with the right tool, could have been there, finished it and be gone. Only you can decide just what you want to do.

As for the boards you are tryng to use for baseboard, no, just save them, in case, you ever need to put up new casings somewhere. Buy the baseboards and put them down, so things look right. Your floors are pretty. Take the time, to put up proper baseboards to frame them.