The space under your sink might not be something you check every day, but what’s happening down there can impact your entire kitchen or bathroom. Whether it’s a slow leak, strange smell, or unexplained puddle, your under sink plumbing could be waving a red flag.
Here are seven signs it might be time to take a closer look—and call in a professional before a small issue becomes a big mess.
1. Persistent Odors
A musty or rotten smell under the sink often signals standing water or mold growth. Leaks in drain pipes or supply lines can trap moisture, leading to mildew and unpleasant odors. If you’re constantly lighting candles or spraying air freshener around the sink, it’s time to investigate.
2. Visible Water Damage
Stained cabinet walls, bubbling wood, or soft spots under cleaning supplies usually mean water has been leaking for some time. The longer it goes unnoticed, the more damage it can cause to both your plumbing and cabinetry.
3. Puddles or Drips
Even a small puddle is a sign of a leak. Check pipe joints, shutoff valves, and the P-trap for signs of corrosion or wear. If tightening connections doesn’t solve the issue, you may have a crack or loose fitting that needs replacement.
4. Mold or Mildew Growth
If you see black, green, or white fuzzy spots around pipes or on the cabinet walls, you’ve likely got a moisture problem. Mold can form in as little as 24 to 48 hours under the right conditions, according to the EPA.
5. Rusty or Corroded Pipes
Galvanized or older metal pipes can rust over time, especially in damp conditions. Corrosion weakens pipes and fittings, increasing the chances of a leak or break.
6. Slow Drainage
If your sink is draining slowly, it might not be a clog in the basin—it could be a buildup or blockage further down in your under sink plumbing. Hair, grease, or food particles often accumulate in the trap or pipe bends.
7. Unusual Sounds
Gurgling or bubbling noises from under the sink could mean there’s air in the pipes or a blockage forming. These sounds often accompany slow drainage and signal that something’s not flowing right.
Local Plumbing Tip for St. Louis Homeowners
In the St. Louis area, older homes—especially in neighborhoods like Maplewood, Tower Grove, or University City—may have outdated plumbing systems that are more prone to corrosion and leaks. Regular checks under your sink can help you spot early warning signs before they become costly repairs.
Time to Call in the Pros?
If any of these signs sound familiar, it’s best not to wait. Water damage can escalate quickly, and what starts as a minor drip can become a major headache. At Beis Plumbing, we’ve seen it all—from leaking traps to full under-sink replacements—and we’re here to help with honest, efficient service across the St. Louis area.
Contact us today to schedule an inspection and keep your plumbing running smoothly.