The crown moulding does not have to be at a 45 degree angle.
Crown molding different ceiling heights.
For 9 foot ceilings 3 to 7 inches and for 10 foot ceilings 3 to 8 inches.
Some suggested crown mouldings for 9 foot ceilings.
The continuous header idea is an additional bridge the same height as the moulding on the 42 unit which is attached to the ceiling with the same continuous crown on it spanning across the lower 30 unit.
Adjust upward for larger rooms.
These larger crowns are often built up using 2 or more moulding profiles and are also referred to as a cornice.
The height of the room as you can probably imagine the height of the ceilings in a room really play a role in whether or not crown molding is good choice.
According to houzz this tip can come in handy for ceilings 10 feet tall or higher consider a rule of thumb allowing 1 of width for each foot of ceiling height.
For standard 8 foot high ceilings the crown cornice height should be 2 to 6 inches.
There are of course more variations but these three examples cover the basic design aspects that you need to consider during the planning stages.
Webber this crown is paired with crisply milled dentil molding and beaded baseboard.
I m going to show three examples of ways to deal with crown moulding at different heights.
You can alter the angle to get a lesser projection with good looking results.
Nine to 10 feet estimate crown molding width by permitting 1 2 inch of rise for each foot of ceiling height in a room with ceilings measuring 9 to 10 feet.