Is That Smell Mold, Mildew, or Something Worse?

You walk into a room and stop in your tracks—something smells off. It’s musty, damp, maybe even sour. You’re left wondering, Is that just mildew… or is it mold? Or could it be something even worse, like sewage or hidden water damage?

At K.O.S. Restoration, we’ve heard this concern more times than we can count. You’re not imagining things—and that strange smell might be trying to tell you something important about your home’s health.

Let’s break it down.

What’s Causing That Musty Smell?

1. Mildew

Mildew is the lighter, surface-level cousin of mold. It often appears as a white or grayish patch on walls, fabric, or tile grout. Mildew has a musty smell but usually isn’t as overpowering or dangerous as mold. Still, it's a red flag that moisture is present—and mildew left unchecked can evolve into mold quickly.

2. Mold

If the odor is more earthy, pungent, or “wet basement-like,” you may be dealing with mold. Mold tends to grow in hidden places: behind walls, under floors, or inside HVAC systems. And it doesn't just smell bad—it can pose serious risks to your home and health, especially if you're dealing with black mold or large infestations.

Common places we find mold on Long Island:

• Finished and unfinished basements
• Attics with poor ventilation
• Behind bathroom walls or ceilings
• Under kitchen cabinets
• Inside crawlspaces

If you’ve been saying, “I think I smell mold, but I can’t find it,”—you’re not alone. That’s where a professional inspection can save you time and stress.

3. Something Worse: Sewage or Water Damage

Sometimes, a smell goes beyond musty. It might be sour, rotten, or ammonia-like. That’s when we get concerned about:

• Sewage backups
• Standing water in crawlspaces
• Rotting wood or drywall
• Bacteria and bio-contaminants left after flooding

If you’ve had a leak, flood, or pipe burst—even weeks or months ago—these odors may be the only clue left behind. And they shouldn’t be ignored.

Don’t Just Mask the Smell—Find the Cause

We understand how frustrating it is to not know what you're dealing with. Candles, dehumidifiers, or air purifiers can help with odors temporarily—but they don’t solve the root problem.

The truth is, by the time you smell mold or mildew, it’s likely already growing. And if it is something worse—like sewage or rotting materials—the longer you wait, the worse the damage (and cost) can get.

How K.O.S. Restoration Can Help

We’re not just here to clean—we’re here to restore peace of mind. At K.O.S. Restoration, we:

• Provide 24/7 emergency service across Long Island
• Arrive in 45 minutes or less to homes in Suffolk County
• Are IICRC certified in mold remediation, water damage, and sewage cleanup
• Use state-of-the-art equipment to detect and eliminate mold, mildew, and hidden moisture
• Work directly with your insurance company to reduce the hassle on your end

Whether it’s a crawlspace full of mold, a damp basement with a mystery odor, or signs of water damage under your floorboards—we’re trained to uncover the truth and fix it the right way.

Concerned About That Smell? Trust Your Instincts.

If something smells off in your home, don’t wait until it becomes visible. Trust your nose—and trust a team that’s been helping Long Island homeowners since 2006.

📍 Located in Bellport, NY
📞 Call (631) 560-8999
🔗 Schedule Your Free Assessment Today »

You don’t need to guess whether it’s mold, mildew, or something worse. At K.O.S. Restoration, we’ve helped  thousands of homeowners just like you who knew something wasn’t right—and needed answers fast. Let us help you breathe easy again.