Should you test?

Start with the question you want answered. Testing should answer something specific.

  • IfVisible growth and an obvious water sourceTesting usually adds little. Fix the water and plan removal.
  • IfMusty odor with no visible sourceInspection with a moisture meter and thermal camera comes first. Air samples may help narrow the area.
  • IfA buyer, seller, landlord or tenant needs documentationAn independent assessment with sampling can provide a written record.
  • IfRemediation is finished and you want confirmationPost-remediation verification by someone independent of the remediator is reasonable.
  • IfSomeone has health symptoms you suspect are mold relatedTalk with a doctor first. Testing the house does not diagnose a person.

Terms you will see in a report

Spore trap
An air sample drawn through a cassette that catches particles for counting under a microscope.
Outdoor control
A sample taken outside at the same time, used as the baseline for comparison.
Tape lift or swab
A surface sample that identifies what is growing on a specific spot.
Hyphae
Thread-like mold structures. Fragments in an air sample can suggest active growth nearby.
Water-damage indicators
Types of mold, such as Stachybotrys or Chaetomium, that typically grow on materials that have stayed wet.

Reading results sensibly

There is no federal standard for an acceptable number of mold spores indoors. Reports usually compare indoor samples to the outdoor control and to each other. Indoor counts much higher than outdoors, or a different mix of types inside than outside, suggest an indoor source. Similar numbers and types indoors and out generally suggest the air is ordinary.

Air samples are snapshots. Results change with weather, activity in the room and how recently the HVAC ran. A single high count is a reason to look harder, not a diagnosis, and a normal count does not prove there is no mold inside a closed wall.

Questions to ask whoever takes the samples

  1. Are you independent from the company that would do the remediation?
  2. What question is each sample meant to answer?
  3. Where will outdoor and indoor control samples be taken?
  4. Which laboratory analyzes the samples, and is it accredited for mold analysis?
  5. Will the report include a visual inspection and moisture readings, not only lab numbers?

General information for Wheat Ridge, not a quote or professional advice. In an emergency, call 911.