The Home Plumber’s Guide to Repairing a Leak Under Your Sink

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A leak under the kitchen or bathroom sink is not only a nagging nuisance but also a sign of a potential water disaster. When you confront this problem, it's important to understand your options and have a game plan in place. While promptly calling a professional is a wise choice for some, many leaks can be fixed with the right know-how and a few essential parts. This guide will explore the basic anatomy of your sink’s plumbing, the common reasons for leakage, and the key parts you’ll need to fix the issue.

The Sink’s Plumbing Composition

The pipes under your sink resemble a simple enough structure with visible parts — like the P-trap — and less conspicuous components leading to the wall. This system, while designed for efficiency, is prone to accumulation of debris, corrosion, or improper installation, all of which can cause leaks.

Spotting the Leak

Before you can fix the problem, you need to find it. Common areas for leaks include around the sink basket, the connections of the drain pipe, and within the P-trap. Watch out for:

Common Culprits for Sink Leaks

Determining the cause of the leak will generally fall into one of these categories:

Deteriorated Seals

Over time, the rubber seal on the sink drain may degrade, leading to leaks. The putty used to seal around the sink basket can also dry out, crack, or shrink, allowing water to seep through.

Loose Connections

The myriad nuts and bolts connecting the various plumbing parts can loosen due to vibration, temperature changes, or just regular use.


Metal pipes and connectors can deteriorate over time, creating holes or weakening connections.

Stocking Your DIY Plumbing Arsenal

Having the right parts at hand can turn a stressful situation into a manageable repair job. Here’s what you'll need:

Sink Drain Basket Strainer

This is vital if your leak is stemming from the drain. It involves unscrewing the existing basket strainer and its defective seals and replacing them with new ones.

Pipe Wrench

This tool is essential for grip and torque when you need to loosen and tighten threaded plumbing connections. Having a pipe wrench with a range of pipe diameters is ideal.

Replacement P-Trap

A P-trap is a curved section of pipe that you can often see beneath the sink. It’s a common culprit for leaks, especially if the integrity of the curve has been affected by clogs or damage.

Taking a crack at plumbing repairs can be empowering, but it’s important to know your limits. If the leak is pervasive or if you're in any way uncomfortable with the repair process, it’s best to call in the professionals.

Contact a company such as Universal Plumbing to learn more.