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Undermount Kitchen Sink Detached from a Marble Countertop, Refastened, Upper East Side

The basin had come down off the marble. All the way around the cutout the stainless rim sat below the marble edge, and the joint between them was open. I lifted the basin back up, set it on new clear silicone, and put four steel legs/brackets under it, screwed to the sides of the cabinet with 16 screws, so the weight sits on the cabinet and not on the caulk line. The job was on the Upper East Side of Manhattan, NY 10128, in New York County.

Before and after of an undermount kitchen sink that dropped from a marble countertop, the basin below the rim, then the four brackets under it — *Before and after. Left, the basin sitting below the marble edge all the way around. Right, the four brackets under it, screwed to the cabinet sides.*

Why the sink came down

The basin was hanging on flat steel clips. Each clip was glued to the underside of the marble, and a screw through the slot in the clip pulled the rim of the sink up against the stone. That is one of the standard ways to hang an undermount sink, and it works until the glue gives up.

Undermount stainless steel kitchen sink sitting below the edge of a white marble countertop, cabinet doors open under it — *Before. The rim of the sink is below the marble on every side, and the joint between them is open. The cabinet is open under it.*

Here one clip came off the stone first. After that the other clips were carrying the whole basin and the disposal on their own, and I got pulled down one after the other. The rim ended up below the marble on all four sides, the joint between them open, with the old glue and grit sitting in it.

Old flat steel sink clips pulled off the underside of a marble countertop, pale glue patches where they were attached — *One of the old clips, off the underside of the marble. The pale patch is where it sat glued.*

It is the same failure as a stainless sink sagging down under a granite top. The joint lets go and the basin goes with it.

Lifting it back with the disposal on it

The owner asked before the visit whether the drain would have to come apart and a plumber called in. It did not. The disposal stayed on the sink, and the drain pipe and the dishwasher hose stayed connected. The basin lifted in place with everything on it, and nothing under the cabinet came apart.

The old silicone comes off the rim of the sink and off the underside of the marble with a blade. Both surfaces are clean and dry before anything goes back on. Then a new bead of clear silicone on the rim, and the basin back up into the cutout.

With a disposal on it the sink is too heavy to hold up by hand. An air shim does the lifting. The bag sits on the cabinet floor on two pieces of wood, the pump inflates it, and the basin comes up with the disposal still hanging on it. It stays up while the silicone sets, and it comes out after the brackets are tight.

A yellow air shim under the garbage disposal of a detached kitchen sink, pumped up on wood blocks to lift the basin back to the countertop — *The air shim under the disposal, pumped up on two pieces of wood. It lifts the sink and the disposal together and holds them while the silicone sets.*

Four brackets, screwed into the cabinet

Two on each side, screwed to the cabinet side walls, one toward the front and one toward the back. The flat arm of each bracket runs up the wall, its top edge comes under the rim of the sink, and the tightening screw in the clamp at the bottom pushes the arm up. That is what carries the basin now. It is bracket installation from under the counter, done with the sink in place.

Five new steel sink support brackets with screws, an Allen key and the instruction sheet, laid out on a counter — *The new brackets. The screw in the clamp at the bottom pushes the flat arm up under the rim of the sink.*

The brackets go in a little at a time, side to side, until the rim meets the marble on an even line of silicone with no gap. No holes go into the marble for this. These brackets hang the sink on the cabinet walls, so the stone is not the anchor any more.

Four steel sink support brackets screwed to the cabinet sides under a stainless kitchen sink, garbage disposal on the drain — *After. Two brackets on each side, arms up under the rim, screws tight against the basin.*

What a re-set sink can and cannot do

The silicone is the seal and the brackets are the support, the same as a new install. Three things to keep in mind:

A full basin of water plus a disposal is a lot of weight. Do not hang on the sink, and do not stand a full pot on the rim.
The silicone line is clear, and in a wet area it can go yellow or peel in time. That line is the one to watch. When it opens, water may get behind the sink.
The old clips are out, but the holes and the glue marks they left on the underside of the marble stay. Nobody sees them under the cabinet.

The marble edge and the old marks in the joint are unchanged. This is the sink re-set, not a refinish of the counter.

The drain and the disposal are plumbing. I left them connected, so there was no plumbing work and no plumber.

Questions people ask about a sink that came loose from a stone countertop

My building wants a certificate of insurance before anyone comes in. Can you provide one?
Yes. I carry general liability and I send the certificate with the building and the managing agent named the way the building asks. Send me the requirements or a sample certificate first.

How soon can the sink be used?
The silicone needs about four hours. The sink can be used right away, just keep splashes off the seam until it is cured.

The countertop looks fine. Does the stone need anything?
Often not. If the basin comes down hard it can chip the edge of the cutout, and a chipped edge is a separate repair, filled and color matched. If the edge is whole, the stone needs nothing.

If your sink has dropped or come loose from a stone countertop, send me a photo of the rim from above, one from under the cabinet, and one of the cabinet side where the brackets would sit. I’m based in Brooklyn and work all over Manhattan. Email info@marblerestoration.us.

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