Should I install plywood on top of my bare cabinets before attaching the granite countertop, or can I attach the granite directly to the cabinets?
Asked by Izzie Knight 
7 months ago
Last Updated: May 10, 2024
I have a question about my granite countertop installation! I put in two base cabinets for my island and have a 4’x3’ slab with 10” overhangs. Should I put a piece of plywood on top of the cabinets before attaching the granite with silicone, or can I skip the plywood and attach the granite directly to the cabinets?
The granite is placed directly on top.
Is there a laminated edge on the granite? If there is, you will need a sub top. If not, then you won’t need one. Keep in mind that a 10” overhang with granite may be too much. There are steel supports available that are not visible in this case. You can find them on Amazon. Granite is not as durable as quartz.
It varies. Is the granite a flat piece or does it have a raised edge that makes it appear thicker? If there’s no raised edge, then plywood isn’t necessary. However, if there’s a raised edge, a 5/8 or 3/4 plywood subtop is needed to ensure clearance for the doors and drawers.
Sure, having a 10” overhang should work well. Our fabricators suggest additional support for anything over 12”, but some may argue that 14” is possible without it.
The company installed granite directly on top, using silicone on the edges. This was for an island and sink area.
No need for plywood. Actually, using it can lead to stability problems later on.
Mounting brackets are needed on the cabinets for supporting the overhanging granite.
What is the thickness of the granite?
Not sure about ‘s comment, it says 1 1/4”
Just use general purpose clear silicone around the perimeter, inside and outside the cabinet to secure it. Avoid sandwiching the silicone/glue.
Hey , could you clarify what you meant by ‘don’t sandwich’?
Hey , avoid using silicone or any other material to attach the stone to the cabinet. Once it’s leveled and the overhangs are in place, simply apply a bead in a way that allows you to easily wipe it with your finger. You can even cut it off when necessary.
Oh, I actually didn’t do that on my cabinets.
Just make sure the cabinets are sturdy enough to support the weight 👍 and consider using butyl silicone underneath to prevent them from shifting.