Why Does My House Smell Weird After Heavy Rain?

Heavy rain can push water through tiny cracks in your roof, walls, or foundation. Once water soaks into building materials, it creates a damp environment where mildew and bacteria thrive, producing that musty smell you notice.

Sometimes the odor is not from a leak at all. If your gutters overflow, water can pool near the foundation and seep into a crawl space or a lower level of your home. A musty smell can also come from your HVAC system pulling in humid outdoor air, so check that as well.

• Check attic and ceiling stains for roof leaks
• Look for water marks near windows and doors
• Feel baseboards and drywall for dampness
• Sniff around the HVAC vents and air filter
• Inspect the crawl space or lowest level for standing water

Start by sniffing around the house to locate the strongest odor. Check the attic, crawl space, and rooms with exterior walls. Use a flashlight to look for water stains, peeling paint, or damp spots on ceilings and walls.

Feel the drywall and baseboards with your hand for cool, damp areas. You can also place a dry paper towel on suspicious spots and see if it gets wet. If you find nothing obvious, the smell might be coming from your plumbing or a hidden leak.

• Use your nose to pinpoint the strongest smell
• Look for water stains on ceilings and walls
• Check under sinks and around toilets for drips
• Press a paper towel against suspect surfaces
• Listen for dripping or running water sounds

Local water damage pros use a process called structural drying and dehumidification. They place air movers and dehumidifiers to pull moisture out of wood, drywall, and concrete. This can take several days, depending on how much water soaked in.

They may also remove water-damaged materials like carpet, padding, or drywall that cannot be saved. After drying, they check moisture levels again to make sure everything is dry. If mold has started, they will recommend a mold professional to handle that separately.