In this guide, we’ll explain why ignoring that small leak is a mistake, what risks it poses to your home and health, and how to fix it before it’s too late.
Why Small Plumbing Leaks Matter
Water can easily become a destructive force in your home if misguided or improperly contained. Even small leaks can potentially lead to the following consequences
- Cabinet damage can result from constant moisture exposure, quickly increasing the cost of what would have been an inexpensive fix.
- Mold and mildew growth can form, harming indoor air quality. This is especially risky for people sensitive to allergies and air contaminants.
- Wasted water will unnecessarily increase your utility bills
- Hidden rot and structural can occur damage if it spreads beyond the cabinet
- Insect or pest attraction can draw roaches, silverfish and other unsightly critters into your home, especially in dark, moist areas
- Electrical or Floor Damage may result from severe leaks or leaks that have gone unnoticed for a long time. This is especially the case for leaks occurring near garbage disposals, dishwashers, electrical outlets These likely require expert emergency plumbing solutions.
Though it may begin as a mere $5 gasket problem, it can easily turn into a $5,000 renovation if not promptly fixed.
Common Causes of Under-Sink Leaks
Leaks under the sink are typically caused by:
- Loose fittings or deteriorated plumber’s putty around sink drains (compression fittings, slip nuts, etc.)
- Corroded shut-off valves and worn-out supply line connections (especiialy braided steel lines past their 5-10 year lifespan)
- Worn faucet seals or gaskets
- Cracked/rusted drain pipes and drain assembly failures (around the flange or from failed plumber’s putty)
- Damaged P-trap connections
- Cracked sink basin (more common for porcelain sinks over steel or old cast iron sinks)
- Leaks from faucet hoses, soap dispensers, or water filters
- Improper installation (many homeowners do not realize that overtightening can easily crack plastic fittings)
While some of these are easy to fix, others can remain hidden behind cabinetry or under items stored below the sink, making them easy to miss until major damage is done.
Signs You Have a Leak (Even If You Don’t See Water)
You might not notice standing water, but watch for these warning signs:
- Warped or swollen wood inside the cabinet
- A musty or mildew-like odor
- Peeling laminate or bubbling finishes
- Small puddles that reappear after wiping
- Visible rust or mineral deposits on pipes and fittings
If you spot any of these, it’s time to take action.
What Can Happen If You Ignore It
Here’s what we often see when under-sink leaks are left unaddressed:
1. Mold Growth
Even slow drips can fuel mold and mildew. These contaminants thrive in dark, damp areas and can pose health risks. Especially for people with allergies, asthma, or respiratory conditions.
2. Cabinet and Floor Damage
Water can warp cabinets, loosen floor tiles, and damage subflooring. Once water soaks through a cabinet or floor, full replacement (not repair) is usually necessary.
3. Structural and Electrical Risks
Leaks near garbage disposals, dishwashers, or other under-sink appliances may affect electrical components, creating a potential fire hazard.
4. Pest Infestations
Roaches, silverfish, and other pests are attracted to water sources. A small leak can provide an ideal environment for them to move in.
Leaks that affect electrical components or flooring may require emergency plumbing repairs.
What to Do if You Notice a Leak Under Your Sink
If you catch it early, the fix might be simple. Here’s what to do:
- Clear the cabinet and dry the area completely
- Inspect fittings, supply lines, and drainpipes for signs of corrosion or looseness
- Tighten loose connections and test for drips (be careful when attempting this; overtightening may crack plastic fittings and worsen damage)
- If damage or mold is present, or if you’re unsure of the source, call one of our professional plumbers
At EVERYDAYPLUMBER.com, our Tampa plumbing professionals provide fast, affordable leak detection and leak repair to protect your home and health.
Types of Sinks and Leak Points
Different Sinks Have Different Failure Points For Leaks
Kitchen Sinks
- Often have more plumbing connections (hot/cold supply lines, sprayer hose, garbage disposal, dishwasher drain).
- Leaks may also come from multiple sources at once — faucet base, P-trap, supply lines, or disposal seals.
Bathroom Sinks
- Usually simpler: hot/cold supply lines, shut-off valves, P-trap.
- But are often in smaller cabinets with poor ventilation, meaning trapped moisture lingers longer.
Utility/laundry sinks
- May use older galvanized or PVC fittings, and often in areas where small leaks are ignored longer.
- Sometimes tied into less-accessible drain lines.
Frequently Asked Questions About “Leaks Under The Sink”
Q: Is a small leak under my sink really an emergency?
It may not require immediate emergency service, but it should never be ignored. Small leaks can signal bigger plumbing issues and quickly lead to hidden water damage, mold growth, and costly repairs.
Q: Can I fix a leak under my sink myself?
Sometimes—especially if it’s just a loose connection or a worn washer. However, if you notice corrosion, mold, water stains, or recurring drips, it’s best to have a licensed plumber inspect and repair it properly. If you have any doubts, it’s much better to call a professional. If a leak is occurring anywhere near electrical wiring, do not put yourself at risk; call one of our trusted experts instead.
Q: How can I prevent leaks under the sink in the future?
Avoid over-tightening fittings, check under the sink regularly for signs of moisture, and keep heavy or sharp items from bumping or stressing plumbing lines.
Q: What if I smell mildew but don’t see water?
A mildew odor often points to a slow or hidden leak. Moisture can be trapped inside cabinets or behind walls, even if no water is visible. Have a professional locate and address the source quickly.
Q: What damage can under-sink leaks cause if left untreated?
Even slow leaks can warp cabinetry, damage flooring, weaken structural supports, and create an environment for harmful mold and bacteria. The sooner the leak is repaired, the less extensive the damage will be.
Q: How often should I inspect under my sink?
A quick check every month can help you catch problems early. Look for dampness, stains, rust, or any unusual smells, especially after heavy sink use or plumbing work.
Stop That Leak From Silently Destroying Your Home
If you suspect a leak coming from under your kitchen or bathroom sink – or any other plumbing system – give us a ring, and we will take care of it with speed and accuracy for a competitive price. We routinely fix leaks in every type of home in every neighborhood across Tampa.
To get ahold of our office, call 813-872-0200 or fill out our easy request form online today. We’ll send one of the best plumbers in Tampa to find the source of your leaks, fix it right the first time, and help prevent future damage. Our work is always performed with honest, affordable pricing and guaranteed results.
Let our family serve yours. We’re committed to dependable results and guaranteed satisfaction.
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“Any Day You Need Us, Every Day We’re There!”
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