On Mon, 12 Apr 2010 09:13:22 -0700, Evodawg wrote:

Have a job coming up where the customer wants to encase his coved doorways
that separate one room from another. The doorways are already coved in
drywall and measure about 8' across, the radius is fairly large. What would
you guys use to encase this upper section of the doorway. Plywood kerf in
back or bent 1/8 - 1/4" Masonite? The encasement will be painted..


IMO kerfing works much better when the kerfs are on the inside of the
curve. The remaining material pushes against each other to keep the
piece from breaking at the kerfs.
Since your openings have a pretty large radius and assuming the radius
on the sheetrock is round enough, I would use two or three layers of
1/4" fiber filled plywood. It will make the bend easily. I would
install the round first and then you can cut the angle on your legs.
This will give you 3/4" material to cover the ends so the round piece
doesn't really have to be fit very closely.
Having been down this road before, I would also suggest removing the
existing drywall corners if the new casing will cover. Usually there
is so much mud build-up that it can be difficult to get the new casing
to lay down.

Mike O.