What Should I Do If I Find Mold Growing Under My Sink?

First, find and stop the leak. Check the supply lines, the drain trap, and the shutoff valves under the sink. A slow drip often goes unnoticed for weeks, so look for moisture on the pipes and around the connections.

If you cannot find the leak, or if water has soaked the cabinet floor and walls, you may need a plumber to fix the source. Meanwhile, place a bucket or towel to catch drips. Turn off the water at the main shutoff if the leak is steady and you cannot control it.

For small patches of mold on hard surfaces, mix a solution of one cup of bleach per gallon of water. Apply it with a sponge or cloth, then rinse with clean water and dry the area. Never mix bleach with ammonia or other cleaners.

If mold has grown into porous materials like drywall, wood, or insulation, cleaning is not enough. Those materials often need to be cut out and replaced. For extensive mold, especially if you have allergies or asthma, consider leaving the removal to local water damage pros.

Once the area is dry and clean, take steps to keep it that way. Fix any leaks promptly and check under the sink monthly for moisture. Use a plastic liner or a waterproof tray to catch drips from bottles.

Improve airflow by leaving the cabinet door open occasionally, especially after using the sink. You can also place a small packet of silica gel or a moisture absorber under the sink. If you see mold again, act quickly to prevent it from spreading.

• Fix leaky faucets and supply lines right away
• Wipe up spills and drips immediately
• Keep the under-sink area clean and dry
• Check for condensation on cold pipes
• Use a dehumidifier during humid months