The short answer
Common Causes of Top Leaks
The most frequent culprit is the seal between the faucet base and the sink deck. Over time, the gasket or O-ring can flatten, crack, or shift, allowing water to creep underneath and run down the sides. A loose mounting nut can also cause the faucet to wiggle, breaking the seal.
Another possibility is the sprayer hose connection. If the sprayer head is not seated properly, or the hose fitting is worn, water can spray upward and pool around the rim. Cracked or missing caulk along the sink edge, especially on a drop-in sink, lets water slip behind the countertop and drip down.
How to Check the Faucet Base
Start by wiping the sink completely dry, including the faucet base and the rim. Run the water for a few minutes and watch where the first droplets appear. If water seeps from under the base, the gasket or O-ring is likely the problem.
Turn off the water supply valves under the sink before you inspect. Gently tighten the mounting nut with a wrench, but do not overtighten, as that can crack the sink or strip the threads. If the leak persists, the gasket may need replacing, which is a straightforward repair for a handy homeowner.
- Look for visible cracks or gaps in the caulk line
- Check if the faucet wobbles when you use it
- Inspect the sprayer hose for loose connections
- Feel under the sink for dampness after running water
- Dry the area and test with a paper towel to trace the leak
When to Call a Plumber
If you have tightened the mounting nut and replaced the gasket but the leak continues, the problem may be deeper, such as a cracked faucet body or a worn supply line. A plumber can diagnose the issue and replace the faucet if needed.
Do not ignore a persistent leak, as water can damage your cabinet base, flooring, and even the subfloor. If you notice swollen wood or musty odors, that points to hidden water damage. In that case, a plumber should fix the source, and then you may need water damage cleanup.
Steps to Protect Your Home
Act quickly when you notice a leak. Turn off the water supply valves under the sink to stop the flow, then dry the area with towels and a fan. This limits the amount of water that can seep into your cabinets and floors.
If the leak has caused significant water damage, such as soaked drywall or saturated wood, you may need professional cleanup. Local water damage pros can assess the extent and dry the area properly. If you live in Mesa, keep your shutoff valve location written down for emergencies.
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Call (480) 898-4279 any time, day or night, and describe what happened.
Call Now (480) 898-4279Frequently asked questions
Can I fix a leaking sink base myself?
Yes, if it is a loose gasket or mounting nut, you can often tighten it or replace the gasket. Turn off the water supply first. If the leak continues after that, call a plumber to avoid causing more damage.
How do I know if the leak is from the faucet or the sink itself?
Dry everything, then run water and watch where it appears. If water seeps from under the faucet base, the seal is likely the issue. If it drips from the rim, the caulk or sink mounting may be the problem.
What should I do if water damaged the cabinet?
Dry the cabinet thoroughly with fans and a dehumidifier. If the wood is swollen or stained, you may need to replace the affected parts. For hidden moisture, consider a water damage inspection to prevent mold growth.