Crown cornice and pelmet
This is a built-up crown cornice according to my own design which incorporates a hidden picture hanging rail. The vertical dimension of the completed cornice will match the dimension of the original stensiling around the top of the wall, which is 200mm (8 inches).
1. Cornice baseboards installed.
Starting with the flat 18x185 base for the pelmet, the full length piece was positioned flat up against the ceiling and fixed in place at each joist with long screws. Curtain rails will be attached to this piece. The baseboards for each side wall were then installed butting up to the pelmet base leaving a gap to the ceiling as seen in image 84. Finally the baseboards for the remaining wall and the vertical side of the pelmet were installed.
Next came the crown molding, which is an extruded paper wrapped plaster product. Each wall used a single length mitred at each corner and fixed using cornice adhesive. With the help of the movable scaffold and a couple of telescopic supports and some temporary nails it became a one man operation, albeit long and stressful because the process is not a forgiving one. There were a few little mistakes and one big one that snapped a length in two as I was dry fitting it to check the cut length. Fortunately this was on the longer of the two wall dimensions and I was able to trim the snapped edges and fit them neatly on the shorter final wall.
To finish the profile, the rounded flat strap molding was installed to cover the baseboard anchor points.
3. Extra hands
4. Finished crown, primed
After reviewing online photos of full-width pelmets and curtain recesses I decided to trim off the baseboards inside the pelmet box (compare images 2 and 5). This was a deviation from the original design. Apart from a cleaner architectural appearance it also simplified the coving inside the box.
5. Finished pelmet, primed
6. Crown cornice as part of the finished ceiling
I found a reasonably priced hanging cable product that fits my rails and comes in either clear nylon or stainless steel. The hook is adjustable and self clamping. They're rated for 10kg each.
Image 7 shows it suspending a framed painting. Notice that the rail is recessed enough to also hide the tail of the metal anchor.
Image 8 is a close-up of the anchor attachment sitting in the rail. The gap in the rail to it's right allows the anchor to be inserted and slid to where it needs to be.
7. Trial of concealed hanging rail system
8. Close-up of the anchor in the rail