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.
Plywood thickness under granite countertop.
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.
However for granite with a thickness of 2 centimeters about 3 4 inches you will definitely need to use plywood for support.
The average thickness of plywood sheets used for backer on counter tops is 3 4 inch.
Remove the granite slabs that were dry fitted only.
You can use it as a stand alone product as well as a finish type plywood if it has a laminate finish that you can paint or finish according to personal preference.
For a truly eye popping countertop many homeowners stack two slabs of 3 cm granite to create the mastadon.
It offers the most durability size flexibility and color options.
Their 33 extra thickness means you do not need plywood under your granite countertops or extra lamination.
You need to have a subtop to glue the granite to.
Depending on thickness granite countertops may be self supporting without underlayment.
Three centimeters is the preferred thickness for both quartz and granite countertops for most countertop fabricators designers and architects.
If using plywood merely as a framework for the finish work surface to be adhered to inch thick plywood is recommended for strength.
This will prevent it from cracking when there are larger.
This provides adequate support for a wide range of finish materials.
Ultimately they will be stronger and more refined.
Granite countertops can come in different thicknesses but the preferred thickness is three centimeters or almost 1 1 4 inch.
Set granite in place for the sink counter and trace the exact line around the opening for the sink onto the plywood subcounter.
Forum responses cabinet and millwork installation forum from contributor k.
Strips of the same type of plywood cut to 4 inch widths should be glued or screwed to the edges of the countertop to strengthen this area making it twice as thick as the rest of the countertop.
Drop in the sink.
Make it about 1 8 larger than the line you drew.
Typically this support includes a plywood base and an underlayment of cement board.
Using proper materials and techniques ensures a reliable long lasting countertop.
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.
3cm material can go directly on top of the cabinets without the need for plywood support.