How to Rid Your Home of Hidden Mold

How to Rid Your Home of Hidden Mold

Mold growth in homes is a common problem that can lead to health issues if left unchecked. While some mold is visible, hidden mold behind walls, under carpets, and in other concealed areas can be even more problematic. Here is a comprehensive guide on finding and eliminating hidden mold in your home.

Locating Hidden Mold

The first step is identifying areas where hidden mold may be lurking. Here are some common trouble spots to check:

Behind Walls and Under Floors

Moisture penetrating exterior walls or leaking pipes inside walls can lead to mold growth in wall cavities. Musty odors, bubbling paint, or wall staining are signs of moisture issues. Use a moisture meter to check for damp areas. Remove baseboards to check inside wall cavities.

Mold may also grow under floors from moisture wicking through the subfloor. Check under carpets and flooring for dark stains or a musty smell. Use a moisture meter on flooring and subfloor.

Inside HVAC Systems

Ductwork, air filters, coils, and other HVAC components with dust buildup can nurture mold. Listen for rattling ducts or fans that may not move air well. Inspect inside ducts, coils, blower motors, and the air plenum for dirt and mold growth.

Behind Insulation

Attics, crawl spaces, and wall cavities containing insulation provide the warm, damp conditions mold needs to thrive. Check behind insulation for black stains or a musty odor. Remove insulation in affected areas to inspect further.

Under Carpets

Spills, flooding, or excess moisture underneath can cause mold under carpets and pads. Check for condensation under edges, a musty smell, or carpet staining. Professional testing may detect mold not visible underneath carpets.

Inspecting and Testing for Mold

Thoroughly inspect any suspect areas and test as needed to confirm or rule out mold.

Visual Inspection

Carefully examine walls, floors, carpets, insulation, HVAC systems, and other areas at risk for visible mold growth or signs like staining and discoloration. Use a moisture meter to detect moisture issues. Use a borescope camera to peer behind walls.

Air Testing

Hire a professional to conduct air testing if the source of a musty odor is unclear. They use specialized equipment to test airborne mold spore levels to pinpoint problem areas.

Surface Testing

Surface sampling using swab or tape tests can detect mold hidden underneath materials. Professionals take samples from suspect surfaces like walls or carpets to be analyzed in a lab.

Bulk/Destructive Testing

To inspect inside walls, professionals may cut small holes and take material samples for lab analysis. Carpets may be pulled up in sections for subfloor sampling. Destructive testing provides definitive mold detection.

Eliminating Hidden Mold

Once you confirm and locate hidden mold, proper remediation is essential. Here are best practices for mold removal:

Fix the Moisture Source

Solve any moisture issues allowing mold to grow, like leaks or humidity. Mold will return if the underlying problem is not corrected.


Close off affected areas with plastic sheeting to prevent spores spreading during work. Remove contaminated materials in sealed bags.

PPE and Containment

Wear proper PPE when handling mold – N95 respirator mask, gloves, goggles. Contain and ventilate work areas appropriately.

Cleaning and Removal

Non-porous surfaces can be cleaned with detergent then disinfected. Porous materials like drywall or carpets generally need removal.

HEPA Vacuuming

Thoroughly HEPA vacuum moldy areas and surrounding areas to capture spores. Replace HVAC filters afterward.

Drying and Dehumidification

Use fans, dehumidifiers, and air conditioning to fully dry affected areas to prevent mold from recurring.

Professional Help

For large affected areas, extensive HVAC mold, or within wall cavities, consider hiring a professional mold remediation company.

Proper identification and remediation of hidden mold requires vigilance and care. But tackling the problem comprehensively removes the health hazards and prevents mold from recurring or spreading to other areas in the home. With the right inspection techniques and remediation processes, you can successfully rid your home of difficult-to-detect hidden mold.