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This document gives advice on how to find, test for, and remove mold in building attics and roof cavities. This is a chapter of "How to Look for Mold" which describes how to find mold and test for mold in buildings, including how and where to collect mold samples using adhesive tape - an easy, inexpensive, low-tech but very effective mold testing method.

Readers of this article series about black, white, green and other colored mold on attic and under-roof surfaces should also be sure to read INSULATION MOLD where we discuss the risk of non-visible problematic mold hidden in building insulation.

This procedure helps identify the presence of or locate the probable sources of mold reservoirs in buildings, and helps decide which of these need more invasive, exhaustive inspection and testing. © Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

IS ATTIC MOLD A PROBLEM ? - Is attic mold a health risk or indoor air quality problem?

Toxic attic mold: The photo at the left was identified as a toxic mold that probably should be removed, although the ease of movement of mold spores from an attic down into a living area varies widely from building to building. Uncertain attic mold: The photo at the very top of this page shows where you may find mold growing on the attic side of ceiling drywall, particularly below roof leaks or in areas of ice dam leaks at a building eaves. We pulled back the fiberglass insulation to expose this small area of mold growth. What about the white mold-suspect material observed on the rafters? Is that mold? If so is it a problem? The answer is, "it depends." In addition to testing to see what this material is (presuming there is a large area of it), we'd also evaluate the chances of particle movement between the attic and the living space before deciding on an appropriate approach to this moldy attic.

It is simply not the case that all attic mold is toxic. It is not the case that all attic mold is harmful.It is not the case that all attic mold needs to be cleaned or removed. It is not the case that all attic mold is going to enter the living area or otherwise be a problem for building occupants.

It is however the case that attic mold indicates damp conditions or leaks and therefore some further investigation or thought are in order.

Be sure to use the links at the left of this page to review other examples of mold found in attics on tongue-and-groove roof sheathing, brown mold and very dark brown, black-looking mold on attic plywood, and the risk of hidden mold in attic insulation.

See   WHERE TO LOOK FOR ATTIC MOLD then  WHAT ATTIC MOLD LOOKS LIKE and also WHAT MOLD LOOKS LIKE.

Also see our photo guide to finding attic moisture and mold at How to Inspect Attics for Condensation & Moisture - to Detect & Correct Attic Condensation, Frost, Ice Dam Leaks & Attic Mold

RISK OF TOXIC ATTIC MOLD - How to Evaluate the Risk of Toxic Attic Mold

Here are some comments about air and particle movement in buildings and thus the chances that attic mold will be transported from that area into the living space.

• Air and particle movement in buildings tends to be up and out from lower floors to upper floors to attic.
• There is not such easy particle movement downwards from an attic into a building.
• Attic mold is less likely to be the significant mold problem source in a building than moldy lower areas such as basements, crawl spaces, or wet building cavities.
• Important exceptions to this normally-upwards movement of indoor air currents do occur however:
  • Attic or whole house fans: When a whole house vent fan is used and the attic venting is inadequate - resulting in a pressurized attic. When the fan is operated, attic particulates, including mold, insect allergens, rodent fecal debris, mite fecals, bird droppings, dust, particles (Histoplasmosis risk), may be blown downwards into the living area or into attic-mounted HVAC equipment.
  • Moldy attic knee wall areas: A moldy attic kneewall space adjacent to a bedroom on the upper floor of a cape cod or similar house.
  • Pine roof sheathing: Older homes using pine boards as roof sheathing use a material which more readily supports growth of Aspergillus sp. and Trichoderma viride as well as other more problematic than I find in plywood-sheathed roofs.

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• Thanks to Alan Carson and Bob Dunlop, Carson Dunlop, Associates, Toronto, for permission to use illustrations from their publication, The Illustrated Home which illustrates construction details and building components. Carson Dunlop provides home inspection education, publications, report writing materials, and home inspection services. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.

Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

FIND MOLD in BUILDINGS, HOW TO
  ATTIC MOLD
    ATTIC MOLD ROOF TEAROFF
    IS ATTIC MOLD A PROBLEM ?
    RISK OF TOXIC ATTIC MOLD
    WHERE TO LOOK FOR ATTIC MOLD
    WHAT ATTIC MOLD LOOKS LIKE
    BEFORE REMOVING ATTIC MOLD
    ATTIC MOLD ROOF TEAROFF
    ATTIC MOLD ENCAPSULANTS
  BATHROOM MOLD
  BASEMENT MOLD
  BLACK MOLD, HARMLESS COSMETIC
  CARPET MOLD CONTAMINATION
  CARPET TEST GUIDE
  CRAWLSPACE MOLD
  DRYWALL MOLD
  DIRT FLOOR MOLD CONTAMINATION
  ESSENTIAL STEPS IN FINDING MOLD
  FLASHLIGHT HELPS FIND MOLD
  WHAT MOLD LOOKS LIKE
INDOOR AIR QUALITY & HOUSE TIGHTNESS
INDOOR AIR QUALITY IMPROVEMENT GUIDE
The Mold Information Center - What to Do About Mold in Buildings

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More Information on Building Diagnostic Inspections and Repairs

Mold and Allergen Recognition and Identification - Not All "Black Mold" is Harmful; Some Suspect Stuff is Not Mold

• How to Find and Test For Mold in Buildings - Looking for Mold - A 'how to' photo and text primer on finding and testing for mold in buildings
• Recognizing Mold: What mold looks like mold identification photos to help identify mold - choosing what to sample in buildings
• Recognizing Allergens: What various indoor allergens look like - identification photos to help identify pollen, dust mites, animal dander, toxic or allergenic mold - Common Mold and other Allergens, Irritants, Remedies & Advice
• Stuff that is not mold but is often mistaken for it - things you may not want to test. Also, not all "black mold" is toxic - here are examples of harmless black mold.
• Mold Action Guide: an easy step by step outline of what to do about mold
• How to find mold without hiring anyone, for do-it-yourself'ers
• Associations: Sick House, Sick Building, SBS - Air Quality, Government, Private Associations and Information Resources
• Mold Test Kits - How to Collect and Send Your Own Mold Sample to our mold testing lab
• How to find a mold inspector or test consultant: Directory of IAQ,Sick Building, Mold Allergen Testing, Building Investigation Service Providers
• Meruliporia: the house eating fungus or "poria"
• Mold Investigation Tips for Home Inspectors how to find mold, where to look, what is likely to be important. Advice to building inspectors intending to inspect or test for toxic or problematic mold indoors, mold inspection methods, and mold test methods which are valid or invalid
• Mold Risk Levels in Buildings Based on Visual Inspection - simple visual clues help decide on action
• Mold in Fiberglass Insulation© 2005 comments about a field study in process, & more about health hazards from fiberglass insulation - DJF
• Frequently Asked Questions About Mold -- check this FAQ list & IAQ Site Map to see if you can find a quick answer to your mold concern
• When to hire a professional to inspect for toxic mold or other allergens
• Contact Us to arrange mold/IAQ building on site inspection and testing.

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The Mold Information Center: What to Do About Mold in Buildings, When and How to Inspect for Mold, Clean Up Mold, or Avoid Mold Problems

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