Palimpsest, Thanks for clarifying the visual aspect. Using the same dimensions for moulding makes sense now. I'll have to take off the crown from the bookcases in order to get the new moulding to fit, but that's ok. I think I'll be okay with having medium dark poplar crown covering dark mahogany bookcases. But what do you think? My mock-up is equivocal insofar as covering the bookcases looks better than coping the new crown to meet the bookcase crowns. I won't replace the base moulding on the bookcases because of the current height and presence of airvents. You've been a great help. If you have any other comments or suggestions, please advise.

Search engine "crown moulding installation" and determine what route is best for your application. No one here can fully explain in detail without really seeing your project as there are various ways to install crown moulding. Some of the variables include size of the trim, ceiling being flat or pitched,( such as a vaulted ceiling), and where, in your case, you need a return for an exposed end, etc. etc. etc.

There is no neat and easy way to run crown there. It would involve splitting the horizontal and vertical portions of each turn into separate transitions. Same goes for turning the main wall run into the raking run. It can be turned in steps or with blocks, but neither is preferable. The old-time Audels-approved way was to have a different profile of crown made for the horizontals and the rakes, which would indeed miter to each other perfectly at the corners, even though they were different profiles and sizes. It's the change of plane in two directions simultaneously that are hard to deal with. Turn any corner in one plane, fine, but add a incline angle to the mix and you're beyond what the molding can do. Casey

hollysprings; Thanks for the reply, I'm not using standard pre mix drywall compound. I'm using a professional grade sheetrock 90 which is premium setting type compound which is not premixed, low shrinkage, crack resistance, much harder set then standard pre mix and feature exceptional bond strength (virtually unaffected by humidity). Most of my previous sentence was a direct quote. I've used this compound on several other reno's and have never had any issues in years, even with large fills. Trebruchet; Thanks for the reply. I've tapped with fiberglass mesh, but my main concern is how far back will you be able to see with a 1" gap along the top of the crown since this compound is hard to work with and my arms are sore after many days of working with the ceiling. I wish I had the option of trial and error once the cabs were up, but I can't afford to have drywall compound everywhere once the cabs are installed plus I can't get into the 5" opening (space between top of upper cabinet and ceiling) to do repairs should the finish not be "good enough. Back to my original question, ""How perfect does the drywall repair have to be if I'm installing 5" crown molding but leaving it approximately 1" from the ceiling. In other words, how far back will you see in a 8' ceiling kitchen?