Close We use cookies to improve your shopping experience. To give your consent, carry on shopping, or change your cookie preferences here.

Kitchen Sink is leaking underneath

Posted by Sinks on 7th Mar 2018

Having trouble locating or pinpointing the leakage in your sink? Not quite sure where it's coming from? With our vast knowledge, we can help you out. Any leakage should always be a priority. It could be potentially damaging to your cabinets, the floor or maybe even drainpipes (depending on your setup). Sometimes the source of the issue can be easily spotted by crawling underneath your sink and using a torch to find the problem. Usually the issue can be easily resolved by tightening a connection but sometimes it can be very complicated.

Once you've spotted the drainage (usually through water-soaked floors etc can indicate it pretty well), and searched it out then you can follow through these checks...

Is it a faulty seal around the drain? - A good way to check whether that is the case, is if you fill the sink with water and let the water stand. Often then the leak will appear.

Is it a water supply issue? - Water in the faucet supply hoses are constantly under pressure, so when it's held in place, it can tend to spray or drip from any loose connections or defective pipelines. In this situation you might often find drips with the source as shut-off valves with compression fittings that aren't as tight as they probably should be. This can be easily solved and tightended by holding the valve with one tool/wrench while turning the compression nut with another. Any leaks that are occuring from cramped spaces should be tightened with an adjustable or locking pliers.

Is it a drainage leak? - Drainage leaks are often the results of loose connections, corrosion (on metal traps) and blockage in the drainpipes. If the trap leaks at all after you've tightened all the compression nuts, you should then remove it to give it a good clean. If it's a blockage, clear it with an auger. If the nuts on a metal trap are hard or tricky to turn, it could well be down to corrosion and you should certainly think about replacing them soon.

Not sure about any of the above? - If you're still not sure, 99.9% of the time, it will be either the sink drain or the faucet. If it is the sink drain, you should unscrew it and repack it with plumber's putty (or something of the like). Faucet issues usually occur above the sink and water will often flow down the back of it and drip underneath without being visible so watch out for that! You can fix your faucet depending on the type you own and have installed. Usually it will involve a replacement of a gasket or a washer.

We hope this guide has helped you to identify your leak. You can take a look at our Plumbing Kit category if you are in need of a maintenance kit for any sink!