Best Humidity Levels to Prevent Mold

Contractor installing spray foam insulation in a crawlspace
Contractor installing spray foam insulation in a crawlspace

CDC Best Humidity Levels for a Home

According to the CDC, it is ideal  to run a humidifier to maintain low humidity levels in your home.  It may work for homes in the north homes but what about our southern Louisiana homes?

Louisiana’s high humidity levels puts homes at high risk for mold.

Scientists say that people typically feel most comfortable when the relative humidity level is approximately 45%. Louisiana’s average yearly relative humidity levels are in the mid-seventies, and during the hottest months, they sometimes climb into the eighties and even nineties. Even though that probably just leaves you feeling clammy, it makes moisture-loving mold as happy as the proverbial clam at high tide.

High humidity outside can spell mold-friendly moisture inside

Similarly, as your home heats up along with the the outside temperature, the humidity inside your home also increases. Simply put, warm air holds more moisture than cool air. And even if you run your air conditioner full-blast in hopes that its dehumidifying component will keep the humidity inside your home in check, there are still lots of little things that can fill your home with moisture-laden warm air:

  • Opening and closing interior and exterior doors and windows
  • Poor insulation
  • An overflowing AC drip pan or other water build-up around your air conditioning unit
  • Inadequate ventilation in laundry rooms or bathrooms
  • Cooking and running the dishwasher

Once humidity levels inside your home exceed the generally recommended 30-60%, mold is likely to come calling.

Signs of high humidity levels in your home:

  • condensation on interior glass, water beading on a window or what looks like a fog or vapor on the glass
  • black grunge on the bottom of window trim or the track of a patio door
  • mold spots, especially on ceilings or corners of walls and under/around toilets, baths, or shower surrounds
  • a musty smell, especially in basements, crawl spaces, entrances or garages
  • water level marks or water stains on walls

Signs that you may already have a mold problem:

  • You smell it. Don’t dismiss this sign even if it’s the only sign.
  • You see it. Even if there’s only a little, there will likely be more where that came from.
  • You feel it. Your stuffy nose, watery eyes and respiratory symptoms miraculously lessen whenever you leave home.

Moisture management is the key to keeping mold at bay

To ward off mold, moisture management, especially in a humid climate like that of Southern Louisiana, is crucial. Too much moisture, and even too much variation in moisture content, puts your home at unnecessary risk for mold invasion.


Main Office: Sunlight Contractors, LLC 2323 Bainbridge St #110, Kenner, LA 70062 (504) 919-9993

New Orleans location: Sunlight Contractors, LLC 650 Poydras St, Suite 1400, Rm 33, New Orleans, LA 70130 (504) 302-0058

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