While poking around for drywall details the other day, I delved deep into USG's online support site for its Drywall Suspension System (www.usg.com/Online_Tools/DWSS/DomeInput.asp). If you're not put off by the words "some assembly required," this is a tres cool product. Essentially, it's a gridwork of curved metal pieces that hang from your framework by wire. Once you have the dome in place (barrel vaults are also possible), a plasterer comes along and applies lathe and plaster. Sorry, drywall won't work here.
USG has gone to great lengths to simplify the design and assembly process. The Web site includes a fancy online calculator. You just enter in the diameter of the room and the dome height you want. The database then generates a full set of construction specifications, including a parts list of the exact number and size of metal pieces you need, with exact placement of the wire hangers.
Also available on the site: a detailed installation manual in pdf format (in English) that includes various elevations and details. The assembly looks pretty complicated, but with this documentation in hand, you should be able to finish the job without a half-dozen calls to the manufacturer.
USG claims that the system will reduce installation time for plaster domes by as much as 50 percent. "The components are completely integrated for fast, on-site construction," says Dan Jacobs, director of marketing for USG. "We ship them pre-engineered, based on specific architectural designs."