How do I prevent water damage under the kitchen sink in NB?

Preventing water damage under the kitchen sink starts with regular inspection of supply lines and drain connections, a quality shelf liner, and immediate attention to any signs of moisture. Under-sink water damage is one of the most common and costly kitchen problems in New Brunswick, where many homes have aging plumbing, and where Maritime humidity makes mold growth especially aggressive once a leak begins.

Inspect your under-sink plumbing every 2-3 months. Open the cabinet doors, remove cleaning supplies, and look carefully at the supply lines running to the faucet, the P-trap, the drain connections, and the dishwasher drain hose if applicable. Run the faucet for a minute and watch every connection for drips. Feel the supply lines — braided stainless steel supply lines are preferred because rubber hoses degrade over time and are the number one cause of catastrophic under-sink flooding. If your NB home still has the original rubber supply hoses from when it was built, replace them immediately — this is a $15-$30 DIY task that prevents thousands in water damage.

Many older NB homes (built in the 1960s through 1980s) have galvanized drain pipes that corrode from the inside, creating pinhole leaks that go unnoticed until significant damage has occurred. If you see flaking, green-white crust, or damp spots on drain pipes during your inspection, have a plumber assess them. Replacing corroded drain plumbing under a kitchen sink typically costs $300-$800 and is far cheaper than repairing water-damaged cabinets and flooring.

Protective Measures

Install a waterproof shelf liner on the bottom of the sink cabinet. A thick rubber or silicone mat catches small drips and contains them before they soak into the cabinet floor. These cost $10-$20 and are one of the cheapest insurance policies for your kitchen. Replace the liner if it shows signs of persistent moisture.

Consider a leak detector. Battery-powered water sensors placed under the sink sound an alarm when they detect moisture — they cost $15-$30 and can alert you to a slow leak days or weeks before visible damage appears. Smart leak detectors that send phone notifications are available for $30-$60 and are worth the investment if you travel or have a vacation property in NB.

Ensure proper ventilation in the under-sink area. In NB's humid summers, a closed, dark cabinet with any moisture at all becomes a mold incubator. If your cabinet does not have adequate airflow, leave the doors open periodically to air it out, especially during July and August when humidity peaks. If you already see mold or mildew, clean with a solution of one part white vinegar to one part water, dry completely, and address the moisture source before it spreads to surrounding cabinets or flooring.

If your kitchen sits on a concrete slab (common in some NB ranch-style homes), water damage under the sink can wick into flooring and along the subfloor without obvious surface signs. This is another reason waterproof flooring like LVP ($2,000-$4,000 for a kitchen) has become the top choice in NB kitchen renovations. If you notice persistent dampness, soft spots in cabinet floors, or a musty smell under any kitchen sink, have a professional assess the situation before it becomes a much larger problem.

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Looking for experienced contractors? The New Brunswick Construction Network connects homeowners with qualified professionals:

• Thirty Four Renovations
• Gionetterenovations