Removing Old Sink from a Countertop Q&A

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Dear NH,

I have a small oval sink in my bathroom that I want to replace. It appears to be ceramic. It is sort of an odd color and I want to replace it with a basic white sink. There are no mechanical fasteners of any kind holding it in, so I think it must be glued down somehow. How can I remove it without damaging the Formica top on the vanity?

DB of Milford, CT

Dear DB,

From your description, I would tend to agree that the sink is glued in. This is a standard way of installing ceramic sinks. The adhesive used… a latex or oil-based caulk… is not super strong but strong enough to hold the sink quite firmly.

Do some sink shopping first. Try to find a sink that is a slightly larger oval. This will give you a little room for error if the laminate cracks or gets scratched during removal. There is a good chance that, even with the same size sink, you will have to enlarge the hole. This can be done with a jig saw and a medium-fine metal-cutting blade. Since the base of the saw may scratch the laminate, apply masking tape before cutting.

Because of the large surface area under the lip of the sink, you cannot simply pry the sink up. If you do, you will most likely break the plastic laminate on the countertop. So unless the sink has loosened of its own accord (i.e. the original gluing was not done properly or the glue has just released due to age), you will have to break the sink apart to get it out. The smaller pieces are easier to pry off and the odds of successfully removing the sink are improved.

First things first. All plumbing fixtures must be disconnected. You may not have to remove the faucet (though it can't hurt), but you do have to turn off the water at the shutoffs and disconnect both the supply lines and the waste lines.

Put on eye protecting and work gloves. Cover the inside of the cabinet with a tarp and/or towels to protect it from falling ceramic pieces and to make for an easier cleanup. Cover the shutoffs with a towel to keep bits of ceramic from getting into them. Close the cabinet doors. Put a towel over the top of the sink to keep sharp flying ceramic chips in control and, with your trusty framing hammer, give the sink a few whacks in the center near the drain. This is the weakest part of the sink and should drop into the cabinet without too much effort. Work around the sink basin until you have broken out the entire inside of the sink.

Be careful to control the force. Hammering too hard can cause the countertop to shift, move or flex causing damage to walls, wall tiles… or who-knows-what!

Broken ceramic edges can be as sharp as a razor and you can get very nasty cuts and splinters from it! Wear gloves when handling the broken pieces!

If you are lucky, the rim of the sink has also cracked and loosened during your merry whacking. Now it gets a little trickier because you do not want to damage the plastic laminate. Hammer around the top of the sink's rim to further break up the sink. I can't predict how much of the sink rim will give way easily. The older the sink, the weaker the glue generally is. The laminate and countertop will flex but both can take quite a bit of abuse before breaking.

Once you have reached a point where no more of the glued sink will release, it is time to begin prying the remaining small pieces off. Since the laminate is also glued, you don't want to pry up from the inside of the sink… this will exert too much force on the inner edge of the laminate and possibly cause it to lift or crack or both! Instead, try this… first, if there is a wide bead of caulk around the edge of the sink, cut it off with a razor or utility knife. Careful… don't scratch the laminate where it can be seen!

(A note about using heat:  Heating the sink with a heat gun (at low temperature) or hair dryer will soften the caulk.  It will also soften the adhesive holding the plastic laminate to the countertop!  Yes, you can use heat to make this final step a little easier, but be careful to not overheat the laminate and limit the heat to the ceramic... don't heat the surrounding laminate!)

Next, use a stiff putty knife or a metal chisel and gently tap it underneath the ceramic piece. Keep your tool angled so that it does not cut into the laminate. Remember… minor mistakes will be covered by the new sink but major errors may force you to replace either the laminate or the entire countertop!

Shift the position of your tool as you meet resistance. This will help to more evenly break the glue bond. When you have all the solid material off, you will be left with caulk residue. Again, you can use a heat gun at low temperature to soften the caulk for easier scraping. The laminate does not have to be immaculately clean… just free of any oils, loose materials or significant lumps. The new sink will cover minor imperfections.