Mold Inspection and Testing

A musty smell with no visible mold, a stain that keeps coming back, or a home inspection that flagged something in the basement. A mold inspection answers three questions. Where is it, why is it there, and how much of the house does it affect.

When a mold inspection makes sense

• You smell mold but cannot see it, which often means it is inside a wall, under flooring or in a crawlspace.
• There was a leak, a flood or a wet basement, and you want to know whether mold started before the area dried.
• You are buying or selling a home and need to know what you are dealing with.
• Someone in the house has symptoms that ease when they leave, such as a stuffy nose, coughing or itchy eyes.
• Mold was removed and you want to confirm the area is clean before walls go back up.

What happens during the inspection

A careful look and moisture readings

We start where the problem shows up and work outward, checking basements, crawlspaces, attics, bathrooms and anywhere water has been. A moisture meter shows how wet drywall, wood and concrete are, which tells us where mold can grow even before you can see it.

Finding the source

Mold always follows moisture. We look for the cause, such as foundation seepage, high basement humidity, plumbing leaks, roof leaks, condensation on cold surfaces, or bathroom and dryer vents that empty into the attic.

Testing, when it will answer a real question

If you can see mold, it needs to be removed whatever type it is, so testing is not always needed. Testing earns its cost when mold is suspected but hidden, when a home sale needs documentation, or to confirm an area is clean after remediation. Air samples compare the spore count inside your home with the air outside, and surface samples identify what is growing on a specific spot. Samples go to an independent lab.

A written report

You get a plain report with photos, moisture readings, any lab results, what caused the problem, and a recommended plan. If the problem is small enough to clean yourself, the report says so.

What a mold inspection costs

National cost guides put a professional mold inspection at about $300 to $1,000, with an average near $690. Each air or surface sample usually adds $200 to $350. Larger homes and widespread problems cost more. See all mold costs.

Black mold and mold types

Many molds look dark green or black, and color alone does not tell you the type. Some molds produce substances that can irritate people, which is why the EPA treats all indoor mold growth the same way. Remove it, and fix the moisture. A lab test can identify the type when that matters, such as for a home sale or a health question. Learn about black mold removal.

Common questions about mold inspection

Can I use a store bought mold test kit?

Kits that leave a dish open to the air will grow some mold almost every time, because mold spores are everywhere outdoors and in. They cannot tell you whether your home has a problem. A professional air test compares indoor and outdoor samples, which is what makes the result meaningful.

How long does an inspection take?

Most homes take one to three hours on site. Lab results, when samples are taken, usually come back within a few business days.