Rcomendations from The Marbel Institue
"If your countertop overhang is more than 6" (using 3/4" stone), or 10" (using 1-1/4" stone), corbels or brackets are required to properly support your countertop."
Unsupported countertop overhangs can crack and fail, ruining your expensive counter top, the flooring beneath and potentially harming someone if it breaks off.
