Mr. Kitchen Faucets is reader supported - if you click on a link and make a purchase, we may earn a commission.

Why Is My Kitchen Sink Leaking Around The Edges?

Why Is My Kitchen Sink Leaking Around The Edges

Kitchen countertops and cabinetry are a major investment.  They define the style of your kitchen and make a statement about your home.  So, of course, you want to protect your investment and prolong their life and usefulness.

When the sink was installed, and if it was installed correctly, the edges around it, whether top mounted or bottom mounted, were sealed to prevent water from leaking into the space between your countertops and cabinetry around and beneath it.

But caulking will deteriorate over time and develop cracks that may lead to chips in the seal – water leaks in between the sink, the counter, and the cabinet underneath the sink.  Mold develops, wood rots, and if left unchecked, this will lead to enough damage where it needs to be repaired or replaced.  Another major investment, sadly.

Should You Caulk Around a Kitchen Sink?

This water damage is easily preventable, and its prevention is inexpensive and easy, even for the DIYer.  Clearing away the old caulk, prepping the work area, and applying the correct caulk are the simple steps to take. 

Silicone caulk is your best choice.  It repels moisture and is resistant to mold and mildew. It will provide a waterproof seal between the sink and countertop, and it has the added benefit of helping to hold the sink in place.

Silicone caulk and silicone sealant are often used interchangeably, but in this instance, you want the caulk.  It is more elastic than sealant, more flexible, and repels water and moisture.  The sealant is better used on windows.

First, though, you must prepare your work area. 

How do you replace silicone around a sink?

The process is actually pretty easy.  This step by step will walk you through it:

  • A straight edge razor blade or a utility knife, some denatured alcohol, a cloth, and some painter’s tape are the only tools you need to prepare the work area properly.
  • Cut away the old caulk along the edge of the kitchen sink and countertop.  Make sure you remove all of it, or the new caulk will not adhere properly and fully to the surfaces of either.
  • Wipe away all of the old caulk you have edged out, using denatured alcohol with a dry cloth.  Let it dry before doing anything else.
  • Use painter’s tape along the edge of the sink and the edge of the counter to create straight lines on either side of the sink and counter intersection.  Do this around the entire sink, sides, and front.

Your work area is now prepared and ready for sealing.

How do you seal the edges of a kitchen sink?

seal the edges of a kitchen sink

Now that the work area is ready let’s talk about caulk.  Choose a silicone caulk for this sealing project.  If you don’t have a caulking gun, and you don’t really need one, choose a silicone caulk in a squeezable tube.

Silicone caulk comes in a variety of colors, with the most popular being white.  However, you could certainly choose a color that blended in well with the countertop and kitchen decor.

When applying caulk along the edge of the sink/counter intersection, within the straight lined space created by the painter’s tape, make sure the bead of silicone is uniform and consistent.  Don’t break the bead; if you have to lift the tube during application, begin a quarter inch back from the edge of the bead to overlap the application.

Squeeze that tube and apply the caulk all around the sink, sides, back, and front.  After you have finished applying the caulk, and with a rubber glove of some sort on, run your finger along the bead all around the sink.  It gets messy, and you’ll be glad you wore the glove.

After you have done this and created a smooth surface all around the sink, remove the painter’s tape.  Don’t wait for the caulk to dry, as the tape will pull the caulk with it and undo all of your hard and good work.

Standard silicone caulks will be dry to the touch within 30 – 60 minutes but will take much longer to cure, 12 – 24 hours, depending on temperature and humidity.  Always use fresh caulk, too.

Here is an excellent video showing the process:

How Do You Fix a Leaky Kitchen Sink Flange?

There’s one other area of possible leak trouble to consider with your kitchen sink.  The flange was sealed at the time it was installed, but gaskets get old and can sometimes fail, or the seal can wear down.  This is another relatively easy fix, too, for the DIYer.

Fix a Leaky Kitchen Sink Flange
  • As with resealing the sink-countertop intersection, you want to prepare your work area.  Remove the contents of the cabinet beneath your sink, and have your flashlight handy.
  • Loosen the drain pipe that connects to the sink using a pipe wrench.  Then, remove the nuts that hold the flange to the underside of the sink, and lift the flange out from the top of the sink.
  • Remove the old rubber gasket from the flange, and with a stiff brush, give the surface a good cleaning to remove all old plumber’s putty and lingering pieces of the old gasket.
  • Rub some plumber’s putty between your hands into a cigar shape and the gauge of a pencil.  Wrap it around the lip of the kitchen sink drain opening.  Then, press the flange firmly into the putty.

Then, reconnect and tighten the flange, and reconnect the drain pipe to the sink. Done.

Kitchen Sink Leak Problems Fixed

In a matter of less than two hours, you can solve the most common kitchen sink leak problems.  Not too bad, really.  The silicone caulk will last for several years, and the flange seal with plumber’s putty will last at least as long, if not longer.

A job well done, DIYer.