When should you test building insulation for mold contamination?

This document explains when and why it is appropriate to test for mold contamination or actual mold growth in certain insulation in residential and light-commercial buildings.

This article series discusses health hazards associated with moldy fiberglass in buildings, with focus on fiberglass insulation, fiberglass fragments, fiberglass in heating and air conditioning duct work, and invisible but toxic mold growth in fiberglass which has been wet, exposed to high humidity, or exposed to other moldy conditions.

When to test building insulation for mold

For cost and ethical reasons, we do not recommend testing building insulation for mold as a regular procedure.

That is because by no means is it always appropriate or justified to test building materials for mold.

Insulation that has been properly installed, not subjected to water leaks, and not subjected to contamination from external sources such as an improperly-conducted mold remediation job should be fine. (Photo at left).

But sometimes it's a good idea. This article explains how to find or test for moldy insulation in buildings, the probable cause of mold contamination in building insulation, and how to recognize conditions that make that problem likely in a particular case.

We would recommend inspecting and testing building insulation for mold in the following cases:

• Fiberglass, cotton, or wood product insulation in any building floor, wall, or ceiling cavity which has been wet. In the photo at left some insulation has fallen onto a crawl space floor where it may have been exposed to water entry. All of this insulation, even in the floor overhead, is suspect of mold contamination.
• Fiberglass, cotton, or wood product insulation over wet or damp basements
• Fiberglass, cotton, or wood product insulation over all crawl spaces
• Fiberglass, cotton, or wood product insulation in attics or roof cavities where there has been leakage or where stains show that there has been a history of high attic moisture, condensation, or inadequate ventilation

• Fiberglass, cotton, or wood product insulation in building walls subject to leaks from plumbing failures,previous wetting due to building fire extinguishment, or in freezing climates, walls subject to leaks from ice damming.
• Fiberglass, cotton, or wood product insulation in buildings if it has been exposed or may have been exposed to high levels of airborne mold or moldy dust and debris from other mold contamination problems or from mold remediation projects, especially if the mold remediation project did not make use of good containment and negative air procedures in the work area.
  
  Certainly test, or simply skip testing and just remove any such insulation that is found inside of a mold remediation project area - such insulation should have been removed as part of the cleanup procedure.
• Fiberglass heating or cooling duct material, especially if it has been wet from building leaks or A/C condensate mishandling

When Not to Test Building Insulation for Mold

Visible evidence of extensive mold contamination may already indicate that insulation needs to be replaced: Insulation that obviously needs to be replaced because it has been in contact with or exposed to heavy mold contamination such as the Memnoniella echinata - contaminated wall cavity in this New York City apartment does not need to be tested. It needs to be replaced.

Exception: for medical reasons such as to provide possibly helpful environmental information to a treating physician, we may test a building or building materials to identify contaminants.

Furthermore if insulation has been soaked from a building leak or fire extinguishment, it should be replaced regardless, and testing is probably not necessary.

Non-suspect low-risk cases of fiberglass insulation: we do not recommend routine testing of building fiberglass for mold in non-suspect cases such as where insulation is new and/or has not been exposed to water, dampness, or other mold contamination sources.

"Spot checks" by "mold testing" in buildings, if conducted without an expert diagnostic visual inspection and history gathering, are simply not reliable and thus not cost-justified.

Other building insulation materials that are not conducive to mold growth: such as

• fire-retardant treated cellulose insulation
• closed-cell insulating foams (though we have found Cladosporium sp. and on occsaion other mold growths on the surface of foam board insulation that has become wet and soiled or dusted with dust that contains organic debris such as pet dander and hair).

are unlikely to be mold-contaminated but might need to be replaced anyway if damaged or soaked.

Watch out:  leaving wet building insulation in place during a restoration project is asking for a future mold contamination issue in the building.

Low-risk buildings where there are no building-related occupant health or air quality complaints: 

See MOLD / ENVIRONMENTAL EXPERT, HIRE ? for more detailed advice on deciding when it is appropriate to hire a professional or to perform further mold testing in a building.

...

Continue reading at TEST CHOICES for MOLD in FIBERGLASS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• BLOWER LEAKS, RUST & MOLD for Readers concerned with mold contamination in heating and air conditioning air handlers and ductwork
• FIBERGLASS AIR DUCT MOLD TEST - using tape to test & identify debris on HVAC duct interior surfaces
• FIBERGLASS INSULATION MOLD - home
• INSPECTION of INSULATION for MOLD before testing - noting that contaminated building insulation may look clean to the naked eye.
• INSULATION MOLD CONTAMINATION TEST
• INSULATION STAINS - AIR BYPASS LEAKS
• TEST CHOICES for MOLD in FIBERGLASS
• TEST PROCEDURE for MOLD in FIBERGLASS
• VACUUM TEST INSULATION CONTAMINANTS
• WHEN to TEST INSULATION for MOLD
• WHY DOES MOLD GROW in INSULATION? that includes photos and test results examining suspected mold on the surface of fiberglass-lined HVAC ductwork.

Suggested citation for this web page

WHEN to TEST INSULATION for MOLD at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to MOLD CONTAMINATION & REMEDIATION

Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia

Ask a Question or Search InspectApedia

Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Note: appearance of your Comment below may be delayed: if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Apologies for the delay.

Only one image can be added per comment but you can post as many comments, and therefore images, as you like.
You will not receive a notification when a response to your question has been posted.
Please bookmark this page to make it easy for you to check back for our response.
Our Comment Box is provided by Countable Web Productions countable.ca

Citations & References

In addition to any citations in the article above, a full list is available on request.

---

ADVERTISEMENT

---