I want to hang a 4ftx3ft mirror (drywall) and frame it with some trim I found (not mdf). I was thinking I would just route the trim, attach the bottom piece to the wall with some finishing nails, rest the mirror in the routed lip, and attach the remaining trim/frame to the wall which would then hold the mirror in place. The trim/frame will be painted.
I have two questions,
In general is holding the mirror to the wall this way bad, Should I use adhesive or the low profile mirror clamps. Both cases I'll still route the trim.
Will I get gaps at the corners because the trim will shrink/expand? Will it be more than some painters putty or paintable caulk can't handle?