"John Weiss" wrote in message
. ..
"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...

Those screws are amazingly strong and if done properly, there's nothing
structurally unsound about an undermounted stainless sink with a granite
countertop. There should be no flex with a decent quality stainless sink.
Make sure the gauge of steel is adequate. Faucets are typically not mounted
to an undermount sink; usually separate hole are drilled into the granite.

-al sung
Rapid Realm Technology, Inc.
Hopkinton,MA