I have a large double glazing unit (1220mm x 610mm) that I would like to use in a new external door I'm making out of red grandis hard wood.
I plan on rebating the glazing surround, leaving the "frame" part of the rebated section on the inside of the door and then adding beading to the outside to hold the glass in.
My question is about the thickness of the rebate and beading. I'm being cautious and have a 15mm rebate and left 20mm for the beading – is this too much? The overall door width ends up at 60mm, and I think that might be far too thick / heavy.
What is the smallest recommended for an external door with 25mm double glazing?
These pictures might help explain it: