countertop substrate & cantilever - Woodworking Talk

Tom Connolly · 02-21-2008, 05:52 PM

Hello folks. I am trying to plan my new kitchen cabinets and have many questions, as I am new to woodworking. My plan is to use two 3/4" cabinet grade plywoods, glued and screwed, for the countertop, then apply 1/2" concrete backerboard, then thinset, then granite tiles (12X12). My question now is: how much can I cantilever the countertop over the back of the base without it deflecting? The overhang will serve as a table, with barstool high chairs. Any suggestions?
Thanks

cabinetman · 02-21-2008, 06:09 PM

If you're doubling up the plywood, and lay 3 tiles deep = 36", you would have approximately 12" of overhang. If you screw from underneath both through the back rail and the front rail, it will be stable.

skymaster · 02-21-2008, 07:13 PM

Tom; double 3/4 ply,THINSET,1/2 cement board then THINSET and tile

Tom Connolly · 02-21-2008, 10:39 PM

Thank you gents. Actually, I should have given you my dimensions, too: Countertop will be 42 inches; base will be slightly deeper than usual--27 inches, which leaves me a 1 inch overhang on front, and a 14-inch overhang on the back. I have a piece of 1/8 T iron and thought about using it to achieve better stability. If so, should I dado it in to the lower ply? I have enough for three pieces to be placed over the six ft. width.