There are seven basic steps in mold remediation, but not all of the steps are required in each project as mold remediation concerns change depending on the size of the project, the individual’s health concerns that occupy the premises, location of the mold, economic conditions, etc.
CONTAINMENT – The affected area(s) must be segregated from non-affected areas so the contamination is not spread. This is typically done by erecting “critical barriers” between the affected area and non-affected area. This usually consists of draping a double-layer of 6ml. plastic over doorways, registers and grills, windows, suspended ceilings, temporary walls, etcetera in an air-tight manner. The purpose of the second layer is to protect the integrity of the containment if one of the layers is damaged.
NEGATIVE AIR SYSTEM – Special HEPA filtered machines are placed in the contained area with the exhaust discharging to the exterior of the building. The goal is to create a “vacuum” in the contained area so that even if the containment is breached, there will be only minor contamination in non-affected areas. The make-up air (intake) is typically introduced into the containment area through a strategically located position, and the opening into the containment area usually is filtered with a MERV rated filter of MERV11 or higher. The rule of thumb for the amount of air exhausted is four ACH (Air-Changes per Hour), however the end result is typically measured as a minimum of .02 water column inches. The contained area must be consistently under negative air pressure until all of the mold remediation is complete.
DEMOLITION – The basic standard for what has to be discarded can be summed up by saying that porous materials that have mold growth within them, they must be discarded. This is referred to as “devastated” materials. Normally, if a material only has mold on the surface, it can be cleaned and salvaged. If the material has mold growth on the interior, it cannot be cleaned and is therefore not salvageable. Value may have some exceptions to this standard. Another rule-of-thumb in how much to discard, is to remove 2 feet of material more in each direction from the visible mold. The devastated materials are bagged into 6ml. bags before exiting the contained areas.
INSULATION DEMOLITION FOR ATTIC MOLD – Typically, if the amount of visible mold growth exceeds 100 SF, the insulation needs to be removed in the affected area due to the large amount of spore deposition that cannot be removed from the insulation. If the attic area needs to be media blasted, all of the insulation must be removed.
PHYSICAL ABRASION – Visible mold growth on semi-porous materials such as wood framing, sheathing, etc. can be successfully removed if the mold growth did not extend very deep into the material. (if it is rotted, the material is devastated) . Normally, mold growth on non-porous materials needs to be removed by physical abrasion. This can consist of numerous techniques such as scraping, wire brushing, HEPA sanding, and media blasting such as baking soda or dry ice. The goal is to not only remove the visible mold growth, but also as much of the staining as possible.
HEPA VACUUMING – As the goal of mold remediation is to physically remove all of the mold spores, the first clean-up method to use is vacuuming with a HEPA filtered vacuum. This vacuuming must be very thorough, and must include every square inch of the affected area.
HAND WASHING – The second clean-up method is to hand wash every square inch of the affected area. This can be done using virtually any type of detergent cleaner. It does not have to be done with a disinfectant, however some professionals will use a sanitizer in their cleaning solution.
SECOND HEPA VACUUMING – After the hand washed area is left to dry, the cleanup is completed by HEPA vacuuming every square inch of the affected area again.
PERSONAL PROPERTY – All of the personal belongings should be cleaned of mold spores. Prior to the remediation, they should be moved to a “clean” room where they will be cleaned. The cleaning methods may vary depending on the construction. The most common cleaning methods to be used include; washing, HEPA vacuuming, and air washing. After the items are cleaned, they should be placed in a “clean” room until the structural remediation is complete. Typically, the personal property that is cleaned of mold spores is not clean in appearance. For instance, a stove that has heavy grease residue built up on it will likely still have the grease residue after it has been remediated. The goal is to remove the excessive mold spores, and that is all. It can be a waste of money to pay a remediation company to do household cleaning that is not required to merely remove the excessive mold spores. However, the personal property after cleaning should be free of visible mold growth as well as dust.
PERSONAL PROTECTIVE EQUIPMENT (PPE)
There are different types of PPE available for mold remediation and choosing the correct PPE is usually done by analyzing the scope of the remediation project. Typical PPE used consists of: Tyvek suits with booties and hood, double-gloves, sturdy work boots, respirators equipped with HEPA filter cartridges (normal selections consist of half-face, full face, and PAPR (Powered Air Purifying Respirators.)
USE OF CHEMICALS
It is not considered proper to use chemicals to kill mold as an alternative to removing the mold spores. However, there are occasions where conditions are favorable to use products such as a sanitizer in the cleaning solution for worker safety, or the use of an anti-microbial in a trouble area to help inhibit future mold growth. It is extremely rare to find an occasion where a disinfectant is used to kill the mold. It is never proper on any project to use bleach as a disinfectant.
INDOOR AIR QUALITY CONSULTANT (HYGIENIST)
Some of the reports written by our company do not insist on having testing services provided by a 3rd party. If we are aware of a special concern due to “high-risk” occupants, we will strongly recommend this service. Sometimes the building owner chooses not to purchase this service due to economic reasons. We feel we have an obligation to inform you the Industry Standard on hiring an Indoor Air Quality Consultant.
- On a large (over 100 SF) mold project, the indoor air quality industry (see Footnote #1) strongly recommends hiring a third party hygienist to perform air testing and to write a remediation protocol. They also recommend hiring a Hygienist when the building occupants include “high-risk” occupants (elderly, people with suppressed auto-immune systems, inmates, children, and people with respiratory problems), regardless of the quantity of mold present.
- The Hygienist must be a disinterested 3rd party, to prevent bias and help prevent skewed reports.
- The main purpose of the testing is to quantify the extent of the mold problem, provide benchmarks needed for effective remediation, to establish goals when writing the remediation protocol, and to use as a measure for clearance testing. This estimate does not include any of these costs, and the scope of this remediation project is based on my best professional judgment based on past experience and training. However, in the event an Industrial Hygienist is hired, he may specify a different scope of work.
- Without performing “Clearance” tests, there can be no written guarantee that the mold spore counts are at an acceptable level.
- If you decide to hire a Hygienist, we can recommend one or more qualified and unbiased professional(s) for these services
Footnote #1 Some of the Organizations and/or Guidelines that agree that post remediation air sampling is recommended for large projects or high risk occupants:
- ACGIH – American Conference Of Governmental Industrial Hygienists
- EPA – Environmental Protection Agency
- IICRC – Institute of Inspection Cleaning and Restoration Certification
- NYC – New York City Guidelines
*All of the above information is trademarked and is the property of RESTORx. We feel it is the most current and accurate information available but we do not guarantee it be the only proper solution. Written by Stephen Gitz, CR, WLS, CMP