I ve seem people saying that a plywood backer is important and some other people saying that it is more trouble than it is worth and the cabinets provide.
Installing plywood for granite countertops.
Maintenance clean your new countertops using only granite and quartz cleaner which you can purchase at most fabrications shops.
They put the stone directly on the cabinets.
Forum responses cabinet and millwork installation forum from contributor k.
Also what is the best way to support the bar that has a 10 inch overhang.
Attach the plywood to the cabinets by drilling screws through the cabinet.
I will have the following run of cabinets which will be screwed together and to the back wall and will install a 20mm 3 4 thick granite countertop over it with sink and cooktop range.
Insert screws upwards to secure the plywood to the countertop.
There is no plywood under the granite.
When installing granite countertops you will not need an underlayment of plywood if the granite has a thickness of 3 centimeters about 1 1 4 inches.
Is it normal not to use a plywood underlayment.
Get underneath your countertops and position an electric drill at one corner of your cabinet braces.
I had some 3cm granite installed in a kitchen.
The plywood supports the granite and gives enough clearance for the bull nose edging to clear the drawers and doors.
However for granite with a thickness of 2 centimeters about 3 4 inches you will definitely need to use plywood for support.
Make sure the plywood does not overhang the outside dimension of the cabinet.