Re: crown molding for upper cabnets
If you're installing full-face cabinets, you're definitely going to want to have some sort of spacer to bump them down from the ceiling. Otherwise the doors will sc**** the ceiling.
What I would do is make the spacer kind of an L-shape, with the horizontal leg of the L attached to the cabinets and the back side of the vertical L. Make the vertical leg about 3/4" shorter than than the space between the top of the door and the ceiling. Attach this leg so there's a gap above the door that's equal to the gap around the door. On the end panel, no gap. The gap above the spacer is irrelevant, as the molding won't attach there anyway, and it will keep you from having to scribe it for a tight fit.
Attach the crown molding to the ceiling. This will ensure that it's tight against the ceiling. A gap against the ceiling is more noticeable than one against the wall (or cabinets). This will also allow a little bit of "float" in case there's any movement of the wall & cabinets relative to the ceiling.
(OK, I haven't done it this way, and I haven't seen it done this way. But I like to be inventive, and this is the way I would do it. I imagine it would work. If someone else can think of a better way, teach us!)
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.