I recently installed 16" porcelain tile in a new laundry room addition. As luck would have it, the room ended up being the same width as 4 tiles, so I had to do very little cutting to complete the job. Everything came out about 1/2" from the wall which I covered with baseboard.
The trade off with going with this layout is that there are 2 locations where I now have about a 1/2" gap that need to filled that won't be covered by baseboard. One is where the floor meets an aluminum sill plate for a garage entry door, and the other is where it joins an existing bamboo floor.
On the bamboo side, I can cut a thin strip (~3/8") of some leftover flooring which will leave me small enough gap to caulk. However, I haven't figured out what route to take where it meets the sill plate. I'm looking for suggestions on how to bridge that gap. It's going to be almost completely hidden by an overhang from the aluminum sweep attached to the door, so the cosmetics are somewhat secondary. I'd like to do something that will hold up well to the invariable expansion and contraction of the aluminum sill plate.
You could use a T-Moulding/Transition Strp
Best Answer
Would a sill extension work for filling the gap at the entry door? Here's the first link I found: http://www.thebuilderssupply.com/Sill-Extensions_c_351.html
And, since you mention that its appearance is secondary, I'll throw out that you might be OK just filling that 1/2" gap with grout. On my first tile job I didn't notice that the edge of my fiberglass tub had a slight belly, and ended up with a gap that went from 1/4" at the middle of the tub (same as my grout spacing), to about 1/2" at the head and foot corners. I filled the gap with grout and it looked surprisingly good. When we moved after about 4 years there was no evidence of any cracking or separation between the tub and the grout; it looked pretty much the same as when I first installed it.
EDIT: Another possibility would be to fill the gap with a length of aluminum bar stock to match the threshold. You could remove the threshold and fasten the bar to its tile-facing edge with countersunk flat head machine screws and nylon-insert locknuts so that the screw heads are hidden in between the tile and the bar. Assuming the cement board is butted right up to the threshold, you'd probably need a 3/8" square bar mounted high on the threshold so it overlaps the cement board.