How to Fix the Leaky Rim of a Bathroom Vanity Sink

© All Rights Reserved

Is there a mysterious leak under your bathroom vanity sink? You might have thoroughly checked all the pipes and found that none of them is leaking, but the bathroom supplies stored inside your cabinet still get wet all the time as though it was a prank by some mischievous imp! If that's the case, then it's possible that water spilled on the countertop has been leaking under the rim of the sink. You can fix this problem by sealing the sink rim to the countertop with silicone sealant. You shouldn't simply squeeze some silicone caulk around the rim and let it dry, though. The best way to do it is to lift the sink off the countertop first before applying the caulk, which requires some special equipment and extra care. Here's a foolproof guide to the entire process.

Adjustable Wrench
Adjustable Wrench | Source
Groove-Joint Pliers
Groove-Joint Pliers | Source

What You'll Need

  • Screwdriver
  • Groove-joint pliers
  • Adjustable wrench
  • Clear silicone sealant
  • Three or four wooden matches or toothpicks
  • Sponge

Tool Selecting Tips

  • Before buying an adjustable wrench, try adjusting its jaws a few times. High-quality wrenches usually open and close smoothly without getting stuck. Also, adjustable wrenches come in several sizes. If you don't want to get a whole set, you should purchase an 8-inch wrench. It's a good size for basic plumbing and small household repairs.
  • There is nothing very precise about the groove-joint pliers. The jaws are effective over a considerable range of openings. Buying a set of different sizes won't be necessary unless you want to become a pro plumber or maintenance man. For simple home repairs, an inexpensive 10-inch model should work wonders.
  • For this particular sink-rim repair project, a small or medium-size Phillips screwdriver is usually what you need. If you're planning to do many other minor home repairs yourself, however, you might want to invest on a full set of standard screwdrivers, or a set of screwdriver insert tips and an insert tip holder.

Under a Bathroom Vanity Sink

How to Fix a Bathroom Vanity Sink's Leaky Rim

  1. Loosen all the sink clips under the sink with a screwdriver by turning the screws counterclockwise. If the sink is loose and can be lifted up slightly from the countertop, go to step 5.
  2. If you still can't lift the sink even a tiny bit, it means the sink might be held too tightly by the attached pipes. You will need to loosen those pipes a little. Before you do that, turn off the water supply valves and turn on the faucet to make sure the water is really off.
  3. Loosen the drain slip nut with groove-joint pliers.
  4. Loosen both supply slip nuts with an adjustable wrench.
  5. Lift the sink up slightly and insert wood matches or toothpicks between the sink rim and countertop. The matches should be placed in different angles around the rim, not right next to one another.
  6. Squeeze a bead of silicone caulk under the sink rim. Make sure there are no gaps, except in the tiny areas where the matches or toothpicks are.
  7. Remove the matches and press the sink down. The caulk will fill the gaps left by the matches.
  8. Use a damp sponge to wipe off any smeared caulk around the sink rim.
  9. Tighten all the sink clips and slip nuts, then turn the water back on. Make sure you tighten them very well, or else you might be creating new leaks in the supply lines! .
  10. Try not to use the sink for about an hour.


More by this Author


Comments 7 comments

rsusan profile image

rsusan 5 years ago from South Africa

Good one with clear instructions and illustrations, Om. Hope I never need this! But it is good to get an idea of what can be done in case of a plumbing hiccup.


Om Paramapoonya profile image

Om Paramapoonya 5 years ago Author

Exactly, rsusan. It's good to know how to repair simple stuff just in case of a "plumbing hiccup"!


anglnwu profile image

anglnwu 5 years ago

wow, you're quite the handy-woman. I sure could use some of the plumbing skills you have. Love the illustration and the clear explaination that go with it. Rated up.


Movie Master profile image

Movie Master 5 years ago from United Kingdom

Hi Om, good clear instructions, I will bookmark this for my husband:-)

Thanks for sharing and voting up.


Om Paramapoonya profile image

Om Paramapoonya 5 years ago Author

@anglnwu - haha I'm not super handy but just know how to fix a few simple things. Thanks for dropping by. :)

@Movie Master - Nice! Have him do all the dirty work! :)


prasetio30 profile image

prasetio30 5 years ago from malang-indonesia

Very well written and useful information. Thanks for share with us. Again, I learn much from you. Vote up!


Om Paramapoonya profile image

Om Paramapoonya 5 years ago Author

Thanks a lot, my friend! :)

    0 of 8192 characters used
    Post Comment

    No HTML is allowed in comments, but URLs will be hyperlinked. Comments are not for promoting your articles or other sites.


    Click to Rate This Article
    working