Planning to use a slab of limestone, 4" high by 8" deep by 5' long, as a floating mantel shelf for a fireplace remodel. The existing fireplace is red (Chicago) brick.
I'm resurfacing with ledgestone overlay. I removed the cheap floating mantel (wood) and plan to hang this limestone. My question is how I should hang it.
I originally planned to use some size of rebar as dowels epoxied into predrilled holes in the brick and the back of the limestone slab. While rebar is strong it tension, I fear pullout or bending that would allow the slab to eventually slip off the supports.
Now I am considering using lag bolts into the brick, cutting off the heads and epoxying into predrilled holes in the slab. Any thoughts on this, or the size of lags, or completely different method for attachment?