I am stapling a 3/4" x 4" Maple floor down on the second floor of my home. The East and West sides of the house will be installed in different directions due to the joists running different directions (so I have the hardwood running perpendicular to the joists). The transition of the joists happens just to the side of where the stairs come in and where the hall has a natural "L" shape to it.

My question is whether I need to install a transition strip (dotted line in drawing) or some kind of expansion gap where the flooring changes direction. The full length of the run (hallway and both rooms on each side is roughly 37'). The hall and room running along the board length is 23' with a 3/4" gap on one wall. The other side is 14' of hall and room running along the board width and will also have a 3/4" gap at the wall.

For the long run I am installing the end tongue into the groove of the other board to give it a seamless look.

If I need an expansion gap or transition piece where the flooring changes direction is there a way to make this look more "finished" or "seamless" so there isn't a hump in the floor with a T-molding or something like that? I am hoping it won't be an issue since the max length of the floor in one direction is only 23' but then again I only have one expansion on one end on the length ways run of boards.

Background: I have decided not to add an additional layer of plywood so that the flooring will all run the same direction for several reasons. My parent’s home (pier and beam) has a similar layout where there is a transition in the hallway but their lengths aren't as much and I can't tell if there is something below the finished floor that allows some movement.

Tried uploading pictures but no dice - have the following slideshow which might help put things in perspective:

http://s181.photobucket.com/user/stormnorm20/slideshow/Hardwood

If your flooring is close to the yearly average moisture content for your area it will not need extra expansion where it has a change of direction, in my opinion. I would glue flooring, where you have the direction changing, to the sub-floor, then use a moisture barrier like aqua bar over the rest of the area, unless you already decided to use glue with fasteners which would eliminate the moisture barrier.