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Big Mold Testing, Inspecting, & Cleanup Mistakes to Avoid: Cross Contamination of Moldy Dust; Relying on Bleach to Kill Mold InspectAPedia®  -     How to avoid unnecessary mold cleanup problems like cross contamination How effective is the use of bleach to get rid of mold? How do we avoid mold reappearance after a mold cleanup? Advice on How to Use of Fungicidal Sealants on Wood Building Materials

Here we explain how an cross contamination by moldy dust or relying just on "mold sprays and paints" can end up costing unnecessarily when hiring a mold cleaning company. This section of our "How to Clean Mold" article describes common mistakes people make when attempting to clean up mold. Avoiding these mold cleanup errors can save you money and may also avoid dangerous side effects of bleach, mold chemicals, or ozone when improperly applied. Photo at page top courtesy of Anabec systems.

We also discuss common errors made when cleaning wood surfaces, such as relying on bleach or performing expensive and unnecessary cleaning on cosmetic black mold on wood surfaces. © Copyright 2010 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use the links at page left to navigate this document or to go to Other Resources. 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.

4. MOLD CLEANING MISTAKES people make when cleaning-up moldy building materials and moldy surfaces, continued.

CROSS CONTAMINATION of MOLD - Be sure to protect from mold spore cross contamination of other building areas when cleaning up mold

Small mold cleanup projects (less than 30 sq.ft.) can normally be handled as a simple building cleaning or renovation project and without expensive negative air and dust containment barriers.

But during a "small project" you should remain alert for the discovery of a previously unrecognized large area of contaminated materials. If the small project discovers that it has become a large one, work should stop to permit set-up of proper dust and particle containment.

When a large building area (more than 30 sq.ft. of contiguous moldy material) is to be cleaned, use of negative air and dust containment are appropriate.

Our photo shows a typical use of plastic pipe frames to support a 6-mil poly dust barrier giving a passage through a building into the mold cleanup area. Our page top photo shows a typical two-barrier air-lock that provides entry and exit into the work area through the containment.

Protect the building areas outside or around the one being cleaned from mold contamination by following published mold remediation guidelines such as the NY City Mold Cleanup guidelines.

For large products (more than 30 sq.ft. of contaminated contiguous surface), the procedure involves tenting or sealing off the work area using plastic barriers, combined with establishing negative air pressure inside the work area so that particles and dust do not tend to escape the work area.

It is important that the mold contractor protect workers performing remediation using appropriate masks, clothing, etc. Occupants, particularly people at extra risk of mold-related illness should not perform nor be present during this work. We sometimes meet mold cleanup crews who do not understand English, have been given no instruction, and have not been giving any protective gear.

Don't spray or power-wash moldy wood or other moldy surfaces without proper containment as you may be simply spreading mold spores around the indoor environment where you will infect other materials.

Do not take down the mold demolition dust containment barrier before the building has successfully passed a mold remediation clearance inspection and test. If the cleanup was not complete, properly performed, and successful, early dust barrier removal risks cross-contamination into other building areas.

Very troublesome has been our observation of frequent complete failures of "mold dust containment" systems set up by un-trained workers.

The result is invariably an increase in the ultimate mold remediation project cost when additional wiping and HEPA vacuuming have to be performed in areas not previously contaminated with mold.

Containment and Negative Air Errors at mold remediation projects include improper containment barrier construction that leaves holes and leaks, collapsing containment systems that simply don't stay in place, combined with workers who simply keep on with demolition even though the containment barrier has collapsed.

It's not too difficult to spot incompetent mold containment barriers (photo at left).

But some mold dust containment barrier setups are downright stupid.

At a New York City mold remediation project we found that the low-budget mold remediation company selected by our client hung plastic up like a shower curtain, (not reaching the ceiling) by suspending it using duct tape strips tied around the fire sprinkler heads along the ceiling!

Not only had the remediator taken down the containment barrier before the project had successfully passed a mold clearance inspection and test, they had left their duct tape plastic strips tied to the fire sprinklers (photo at left).

Luckily no one stumbled into the "shower curtain" containment system or the building would have had a new shower of its own, with new mold problems.

And luckily the building had not caught on fire - we don't know how the duct tape might have interfered with proper functioning of the sprinkler heads in the event of a fire.

Also ineffective is simply "air scrubbing", running power dryers, or power dehumidifiers in a moldy dusty area, without also performing the cleanup and fixing any ongoing water entry problems or water leaks.

Turning on a large air filtration machine with no ducting to outdoors. The result may stir up and remove dust that is airborne, but an air scrubber is completely incapable of removing mold from building surfaces nor can it pick up debris on the floor across the room, any more than you can vacuum your living room carpet by standing in the kitchen and waving your vacuum cleaner wand in the air.

Our photo (left) shows a "post mold remediation" condition we observed while inspecting a property for a large homeowners' insurance provider. Things didn't look quite right:

• A drier and dehumidifier were left running in a moldy crawl space that was still wet (see that dark spot at center of the photo)
• Demolition was incomplete (see the fiberglass insulation in the upper left of the photo)
• There was no evidence that any dust containment had ever been in place, though this crawl space communicated with the rest of the building via several major air pathways.

See

• Mold Remediation & Cleanup Standards
• Mold Levels: allergenic or toxic mold: how much means a problem
• Mold Cleaning, Remediation, & Clearance Testing Standards list of documents

USING BLEACH - Bleach as a "Mold Medicine" to try to kill mold or prevent mold in buildings

Bleach, diluted bleach, or bleach sprays used in cleaning may be appealing but they are unnecessary, potentially dangerous (if you get bleach in your eyes), and the use of bleach tends to lead to improper and inadequate cleaning - if you substitute "spraying bleach" for actually cleaning or removing the mold your cleanup will not be successful.

Leaks at the window (photo at left) led to mold growth behind wallpaper as well as in the wall cavity. Surface cleaning of the wall was ineffective and occupant complaints continued in this building.

The object of mold remediation is to clean, or remove, the majority of the mold particles (spores, conidiophores, hyphae, mycelia) from the target surface. The operative word to fix in mind is to "clean" or "remove" the problem mold.

"Killing" the mold is not the object - first of all because our lab work shows that you're unlikely to kill all of the mold on a surface using bleach, unless you use it at a concentration and duration which is so strong that you're likely to completely destroy the "bleached" material, and second of all because even if you could "kill" every mold spore, you are at risk of leaving toxic or allergenic particles in place - they may be dead but still toxic.

Our photo (left) shows nice healthy black Stachybotrys chartarum spores collected from a "mold-killing bleach" treated surface in a building.

Finally, "mold removal" only works if you're cleaning a relatively hard, non-porous surface such as finished wood, painted metal, or plastic.

Soft materials like Sheetrock™ or drywall which have become moldy generally should be removed, the exposed surfaces cleaned, and then new drywall can be installed (after you've also corrected the reason for the mold growth in the first place).

Spraying anything if spraying of fungicides or sealants is to be used in place of actual cleaning or removal of mold is an improper and inadequate practice which risks leaving a reservoir of toxic or allergenic particles in the building.

See MOLD CLEANUP with BLEACH for details about using bleach to clean up or treat moldy surfaces.

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MOLD CLEANERS - WHAT TO USE
MOLD CLEANUP COMPANIES
MOLD CLEANUP GUIDE- HOW TO GET RID OF MOLD
CLEAN MOLDY SURFACES
  CLEANING SMOOTH WOOD
  CLEANING IRREGULAR SURFACES - MEDIA BLASTING
  CLEANING MOLDY WOOD TRUSSES
  SANDING WOOD TO REMOVE MOLD
DRY THE MOLD-CLEANED SURFACE
FUNGICIDAL SPRAY & SEALANT USE GUIDE
  ADVANTAGES
  WARNINGS
  SOURCES & TYPES
MOLD CLEANING MISTAKES
  UNNECESSARY COSTS
  INADEQUATE REMEDIATION PLAN
  INCOMPLETE CLEANUP, RELYING ON SPRAYS
  CROSS CONTAMINATION
  USING BLEACH on MOLD
  USING OZONE to KILL MOLD
  HOW TO PREVENT FUTURE MOLD
  COSMETIC MOLDS
MOLD CLEANUP LIMITATIONS

• Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. (727) 595-4211 mark@BestTampaInspector.com 11/06 and 04/2008
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More Information on Building Diagnostic Inspections and Repairs

• Action Guide for Mold: what do I do about mold in our home? Step by step instructions.
• Humidity: What indoor humidity should we maintain in order to avoid a mold problem?
• Mold Levels: allergenic or toxic mold: how much means a problem
• Not Mold, Stuff that is harmless or cosmetic-only
• Ozone Generators Indoors, The Use of for Control of Odors and Mold Removal in Buildings: A Summary of Hazards and False Claims
• Prevention: Avoiding Mold Problems in Buildings by Using Mold-resistant Construction Products & Practices
• Prevention of Mold list of articles on how to Correct the Causes of Mold and Prevent Indoor Mold or other indoor environment problems
• Standards: Mold Cleaning, Remediation, & Clearance Testing Standards list of documents

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