I am installing some 3/4"H x 2 1/4"W red oak in my master closet (about 36 sq ft) as a test run for the rest of my house, and I am having some questions after installing about 1/3 of it. I used the old rule of using the same width of the board as my expansion gap. However, when I am coming to the jambs, the boards don't even reach the trim. This also sparks questions in my mind about trim well. What can I do to avoid having to rip it out and start it over (and in the process severely pi$$ing off the wife)?

When it comes to movement, your "test run" of 36 sq. ft. isn't going to be an accurate test, comparing to the larger footage of the rest of the house. Also doesn't take into consideration seasonal changes, and a number of other variables.

In answer to your question...Under cut the door jambs and casings deep. On the walls...remove the base, and either add a shoe moulding to the base, or cut out the drywall for added space,( if you don't like the shoe moulding look).

The test run really is whether I can actually install the floor without messing it up too badly, not for movement, and the margin for error is razor thin. The wife still has her doubts, but it is going relatively smoothly even though this is my first attempt at installing hardwood.

As for cutting the jambs and trim, how deep would you recommend cutting them? I have removed all of the base trim in the room, and cut all of the jamb and door trim off up to a height matching the width of the wood I am using.

The area where I am struggling the most is the transition from hardwood to carpet. I bought a piece of transition at Home Depot, but that was about the dumbest thing I could do, as I bought a prefinished piece, and it doesn't look like it is going to do the job. Any helpful hints on that?

Check out these videos on youtube for how to undercut. Most of us pros use the Fein supercut or Multimaster to cut our trim and jambs

http://www.youtube.com/watch?v=kS61rCNqAso

http://www.youtube.com/watch?v=oFF6zbD8 ... re=related

http://www.youtube.com/watch?v=gvmug65WFp8

On 90% of the buckling claims I have investigated, the expansion space still existed. The other 10% were isolated areas near a wall, where construction debris had been in the expansion gap.

I personally have never left ¾" expansion on any wood I have installed.
½" is the max I have left.

I do live in a region, that the rH is fairly consistent year around, with a very short winter.