"John" wrote...
Urgent! undermount stainless sink advice need!!!
My contractor is to install undermount stainless sink & granite counter
top tomorrow, but he told me that I will have to break the granite if I
decide to change the undermount sink later on, is this true or he does
not know how to install undermount sinker correctly?

We are in the process of replacing our counters with granite. After shopping
around, my conclusion is that undermount sinks are not a good idea with granite.
They are better suited to Corian type synthetics.

The typical undermount screws into the underside of the counter with 4 mounting
screws. While the entire rim may be sealed with silicone, that glue will flex
considerably more than the screw when overstressed. By contrast, a self-rimming
top mount sink is supported by the entire circumference of the sink and slab.
While "typical" use of an undermount sink may not cause any failures of the
sink, rock, or mounts, I think a top mount is a much more structurally sound
system.

One of the installers we talked with said he would not put an undermount on a
granite countertop without a structural wood "sink box" underneath to support
the sink. He did not describe it fully, but he obviously did not trust the
typical undermount. Remember, the weight of the sink alone is nowhere near the
total weight. You have to add the water, faucets, disposer...

Also, silicone glue CAN be cut with a razor knife, but it is a tedious job...