How Do Mount an Undermount Stainless Steel Sink When Installing New Granite Countertops?

Question

We are updating our kitchen, removing the old tile and countertops and replacing the sink too. The current model is a drop in ceramic.
We are reinstalling new granite countertops with new plywood support underneath.
The new sink is stainless steel undermount. I know the granite people can cut out the plywood and rest the flange thru the cutout, but that means the granite is not level. the other way is to use some brackets or braces under the sink, how is that done??

Answer 1

They usually grind t-slots underneath the granite. Then they use t-bolts the slide in and bolt and silicone the sink underneath. Otherwise they have some new bolts the you drill a hole and epoxy in and then bolt the sink up after the epoxy dries.

Answer 2

Based on your description of your new counters; I would cut out the plywood hole as you described but also cut a part-depth oversized area to fit the outside dimension of the sink overlap edge. You could use a circular saw at a low cut depth to do the cut and then a chisel to lift away the part of the wood from the full cut hole to the part depth cut line.
As an example of my sad description here, imagine a door latch mechanism and how the carpenter sinks the catch plate (srtike plate) part of the way into the door frame so the plate is flush with the frame. You can do the same in this application and use the standard mount hardware to fix your sink to the plywood and then place the granite on top. It should all sit flush as you have recessed the sink into the plywood. Once all is in, silicone around the join between the sink and granite.
Might work eh? Good luck!

Answer 3

Normally this is a special sink, sometimes fastened to the granite, sometimes supported independently. It's usually done when the top is installed, not as a later modification. The catch is that the hole in the top has to match the sink. I have installed standard sinks as undermounts by providing sufficient bracing under the rim to support the sink in contact with the bottom of the counter material, and sealing the sink's rim to the counter with silicone. You also need to provide a way to replace the sink if needed without replacing the countertop. To do that, the bracing needs to be installed with screws, removable from the bottom to allow you to drop the sink. It also has to be strong enough to hold the fully loaded sink weight, so it does require some skill and unserstanding of the support requirements. Builder I

Answer 4

Generally the Granite contractor mounts the sinks by glueing the sink to the underside of the granite. They will cut a piece of wood and stand under the sink until the glue dries.