I am getting ready to install black cherry T&G flooring in my home. I will be installing 3/4 cdx plywood over concrete with a 10mil vapor barrier between the plywood and the concrete and felt between the plywood and the cherry. I have 1800 sqft stickered in a bedroom acclimating to the internal environment. My question is regarding the installation of the flooring under the door casing. The casings in my home are very thin, maybe 5/8ths of an inch at it widest point and then narrows down to 3/8ths of an inch at its narrowest point. If I leave a 3/4 inch expansion gap then the edge of the flooring will show. Is the proper method to install the flooring with less than a 3/4 gap just under the door casing but leave the 3/4 expansion gap everywhere else?

Get in there with an undercut saw and a chisel. Take out part of the stud if you have to. I don't worry about it that much out here. But I'm out here in the desert.

I just used a dremel multimax with the half moon blade, used a scrape piece of wood, it was actually better than the jamb saw i rented for my tile floor.

Wait till you try the $99 Bosch Finecut saw. That thing is awesome. I've undercut probably a hundred door casings and I am only on my second thirteen dollar blade.

yeah, those blades are priced completely rediculous. especially those multimax blades.