Spring Allergies and Crawlspace Health: What Every Homeowner Should Know

As winter fades and spring arrives, most of us look forward to warmer days, blooming flowers, and fresh air. But for many families, spring also brings something far less pleasant: allergies. While pollen gets most of the blame, there’s another seasonal factor many homeowners overlook—what’s happening underneath their home.

The Spring Mold Bloom: An Invisible Trigger

When temperatures rise and humidity returns, crawlspaces across the South go through a predictable cycle. During winter, cooler air keeps mold activity low. But as soon as conditions warm up, crawlspaces experience a “spring mold bloom” —a surge in mold growth fueled by moisture, stagnant air, and porous wooden framing.

This mold growth often begins weeks before homeowners feel the first wave of allergies outdoors. And because up to 50% of the air you breathe on the first floor comes from the crawlspace, the effects can show up inside your home long before you open the windows for the season.

For families with seasonal allergies, asthma, sinus problems, or sensitive immune systems, this invisible bloom can significantly worsen spring symptoms.

Why Crawlspace Conditions Matter

A healthy crawlspace supports a healthy home. When moisture accumulates beneath your home—whether from heavy spring rains, leaking pipes, or poor ventilation—it creates the perfect environment for:

• Mold and mildew growth
• Musty odors entering the living space
• Warped or weakened floor joists
• Higher humidity indoors
• Dust mites and other allergens

Even homes that “felt fine” during the winter can flip quickly in spring because crawlspaces become humid long before outdoor air does.

Recognizing the Signs in Your Home

Many homeowners are surprised to discover their spring allergies are worsened by something happening under their feet. Look for these clues:

• Increased sneezing, coughing, or congestion indoors
• Musty or earthy smells, especially after rain
• Cold or bouncy floors
• Condensation on HVAC ductwork
• Visible mold on floor joists or insulation
• Higher-than-normal indoor humidity

If these appear each spring, it may not be a coincidence—your crawlspace might be going through its annual mold bloom.