Should a Replacement Undermount Sink be Installed to Granite by a Plumber or a Granite Installer?

There is an existing composite sink, and the installation has failed, leaving a gap between the counter and the undermount sink. I would like to replace the sink with stainless, also the faucet and possibly the disposer. Not sure why the existing install has failed, so I feel I will need an extra-competent installer.

Answered by LCD: Most likely failed because it was jsut glued on with epoxy (or sometimes just silicone caulk - NOT at ALL what that is designed for - a common cause of failure. The mounting mechanisms for undermount sinks are typically the pits - not thought out or strong enough considering the weight of a loaded sink full of water and dishes, plus commonly carrying the weight of a garbage disposal as well.

I always recommend embedded anchor bolts and metal brackets if countertop is thick enough (generally about 3/4" or more) with the caulk or epoxy between sink and countertop just being counted on for providing the waterproof seal between sink and countertop. Otherwise, mounting treated wood support pieces (typically 2x3 or 2x4) across the underside of the countertop or across the cabinet to screw mounting brackets into, or with some flimsy or very large double or triple sinks to directly support it from the underside, though that can make plumbing a bit more of a hassle but sometimes better than none at all. This type of direct under-support can be especially needed with thin porcelain or the new colored or fused glass sinks and true stone sinks like marble or soapstone, though why anyone would buy a glass sink is beyond me - talk about an invitation to failure when mugs or frying pans or such get dropped into it.

I would definitely go with a Countertop specialist (your Search the List category)- who will sometimes but not always also reconnect the plumbing underneath. Since you are talking replacing faucet and disposal replacement they may say get a Plumber in for that once the sink is mounted - or get a Remodeling - Kitchen and Bath contractor to handle it all, though a bit of overkill for this size job probably.

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