A bit of water under the sink: should I worry?

June 10th, 2021

When water starts to drip and puddle under the sink, it’s time to act. A big part of the worry that homeowners experience comes from not knowing whether the plumbing problem is serious or not.

There are a number of different possible causes for a leak under the sink and so the first step is always identifying where the water is coming from and then choosing the best solution. Some under-sink leaks can be easily fixed by DIY home plumbers, whereas others are more complex and should be left to professional plumbers.

In this article, the plumbing specialists at Plomberie Lalonde in Gatineau will share some insights about the different reasons your sink might be leaking and how to find out exactly where the problem starts. Regardless of how big or small your problem is, never hesitate to call us for help – we offer all sorts of home plumbing services and are always happy to help!

Identify the water source

There are some common culprits when it comes to leaks under the sink. The solutions for these problems differ according to the source of the water that is leaking. As such, step 1 in dealing with a leak under the sink, whether it’s in the kitchen, bathroom, or utility room is to find the exact location of the water leak. Let’s walk through some simple steps to help lessen your worry and decide whether or not you should call in a plumber.

Tools needed

The only tools you’ll need to start is a flashlight (or bright cellphone screen) and some paper towel. Start by wiping away any existing water and then use the paper towel to explore and dab for fresh drips. You might need to change the conditions in order to cause more water to leak under the sink. To do that, you can use these 4 leading questions to troubleshoot and narrow down the possible water source contributing to your leak.

1. Is the dripping or seeping constantly or only when there’s water in the sink?

If the water is constantly streaming or trickling in even when the sink is not in use, the problem is with your water line. Turn off your undersink water supply line to see if the problem stops. If not, then you might need to turn off your main house water supply line because the leak could be coming from the water lines within the walls or floor. This will most certainly be a job for a professional plumber.

If the water only appears only when there’s water being used in the sink or when the tap is on, then the problem is most likely associated with your sink or tap as opposed to your water lines. Proceed to the next question to narrow it down a bit.

2. Do the drips only appear when the faucet is turned on?

To find out if the leak is coming from your faucet fixture, put the plug in, or close your sink drain and then turn on the tap. If the leaking water only worsens when the tap is running, as opposed to when you pull the plug to empty a full basin, then the leak could be linked to your facet. But it could also be a problem with your sink drain seal. Test this with question 3.

3. Does the water drip when the plug is firmly fit in a full basin?

To determine if the drip is coming from the drain seal, plug your sink or close the drain stop then fill your sink with water. Look for drips that occur after the faucet is turned off. Drips resulting from these sink conditions are likely a sign of a leak around your drain or from a crack or hole in your sink basin.

4. Does the water drip only when the sink is draining?

If you still haven’t had any drips after setting up the conditions in the first 3 questions, your under-sink leak could be caused by a problem with your drain pipes. To find out for sure, put in the plug, fill your sink, and then look under the sink after you’ve pulled the plug or opened the drain. You can narrow down the location of the leak even more by wrapping your dry pipe with paper towel and watching for the first sign of moisture when you run the test again.