Mold Prevention and Control
By James Holland, REA, CR, WLS
Applying the appropriate restoration
procedures within the first few hours of a water loss can save thousands of
dollars in secondary damage. The following suggestions will help to control
the scope of repairs and therefore reduce costs.
Time is of the essence when dealing with water or moisture problems in
buildings.
The primary physical damage from
water or moisture problems usually includes wet floorcoverings, walls, ceilings
and furnishings. Secondary damage to other furnishings or structural components
can result from high indoor humidity or molds that may develop in areas of
the building that are not properly dried. Prompt response with the appropriate
mitigation procedures is essential to minimize secondary damage and the costs
of restoration.
If water or moisture problems are
not promptly and appropriately attended to, molds and other microbes can begin
to grow. These microorganisms can feed on a variety of materials including
wood, paper, paint, adhesives and backing materials. Before the growth of
molds becomes visible, there will be a faint musty or earthy smell. In time,
the molds may appear on the outside of the wall as a stain or discoloration.
The following suggestions will help
you to control moisture related problems.
1.
Control microbial contamination in
building by regularly inspecting for and promptly repairing water and moisture
intrusion problems.
- Control microbial problems
in buildings by promptly drying wet or damp building materials according
to procedures in the IICRC (Institute of Inspection, Cleaning
and Restoration Certification) S500 Standard
and Reference Guide for Professional Water Damage Restoration.
- Remove and replace wet
or damp porous building materials (i.e. drywall) that have visible mold
growth.
- Where wall cavities or other concealed areas of
the building have been wet for over 72 hours, an investigation of the affected
area must be performed to establish whether or not there has been an amplification
of mold. In conducting this investigation, care must be taken to insure
that the indoor environment does not become contaminated. Precautions should
be taken to minimize cross contamination from affected to unaffected areas.
It is recommended that contaminated areas be contained with polyethylene
sheeting, often in combination with negative air pressure, to prevent cross
contamination. In some cases, it may be necessary to shut down air handling
equipment and seal off supply and return registers.
- Visible mold, that is
growing on building system components or other impermeable surfaces, should
be removed by HEPA (High Efficiency Particulate Air) vacuuming if dry; by
physical removal from the surface while HEPA vacuuming; or by removing and
replacing the affected building material. Other areas that have been contaminated
with settled spores may be cleaned using an appropriate method for that
material.
Providing appropriate mitigation services.
The Institute of Inspection, Cleaning
and Restoration Certification (IICRC) has published the “IICRC Standard and Reference Guide for Professional
Water Damage Restoration S500”. This Standard is intended to provide current and accurate information
about the restoration of water-damaged structures and their contents.
While some jobs may not require dehumidification,
airmovers alone only serve to move moisture from the water soaked material
to the air space. If the moisture is not taken out of the air space, drying
slows down and secondary moisture damage to other surfaces and contents can
result. A clear understanding of psychrometric principles is a necessity in
performing restorative drying services.
The length of time that the drying
equipment is needed is dependant upon maintaining a low relative humidity
(RH) in order to reduce the moisture content (MC) of structural components.
The reduction in MC is the real indicator of whether or not there is sufficient
amount of drying equipment. The dry air is the “tool” used to dry the building
and contents.
Monitoring
The damaged structure must be monitored starting with the initial
loss assessment and evaluation, and continuing throughout the restoration
process. It is highly recommended that technicians establish a moisture content,
or drying goal, for affected building materials and contents items.
Monitoring
procedures may include, but are not necessarily limited to, temperature and
humidity readings, updating progress reports and checking the moisture content
of structural wood and other materials with a moisture meter. When applicable, monitoring also must include
checking equipment operation, work progress and indoor environmental quality.
Final Inspection and Completion
At the conclusion of a restoration
project, a final inspection, including the implementation of completion procedures,
must be performed. During final inspection
and completion procedures, it is important to confirm that the structure and
contents have been returned to a pre-loss condition or that materials have
met the predetermined drying goals.
For very large homes, crawl spaces,
commercial projects or any otherwise unusual drying project, consult with
an ASCR Water Loss Specialist or an IICRC certified Water Restoration Technician.
The phone numbers for both organizations are listed below.
Failing to Properly Dry a Building Can Have Long Term Consequences
It is well documented that mold contamination
in buildings can cause significant health problems. These problems can include
simple allergic responses such as eye, nose and throat irritation, excessive
colds and flu, lowered immune systems, acute mycotoxicosis (a severe reaction
to mold produced toxic chemicals), mold induced asthma, mold lung infections
like aspergillosis, and chronic debilitating lung diseases such as hypersensitivity
pneumonitis.
Mold spores can lay dormant for years
and when ideal growing conditions develop, they start to flourish. As summer
approaches, the warm humid conditions are a perfect microenvironment. Bacteria
can start to grow within hours and mold can grow within days. As the days
of summer pass by, the odor from hidden pockets of mold may become more noticeable
and in more severe cases, the mold growth may become visible. The greatest
risk of adverse health consequences from exposure to microorganisms can occur
during the cleanup process. In fact, the City of New York has issued guidelines
for the removal and cleanup of buildings that have mold problems. The New
York Guidelines follow an asbestos abatement-like approach to the process.
The emergence of mold and sewage
damage remediation (or cleanup) technology is relatively new. There are very
few guidelines available to the general public or the professional water damage
restorer. An environmental consultant experienced with water-damaged buildings
and microbial contamination issues should evaluate all buildings that need
to be or have been remediated.
Microbial Remediation Overview
The IICRC S500 makes the following comment “When visible microbial growth has occurred in a structure,
mold remediation practices must be properly employed to address the situation,
and containment procedures may be necessary to prevent spreading spores to
uncontaminated areas. Remediation requires (a) removing porous materials exhibiting
extensive microbial growth, (b) physically removing surface microbial growth
on non-porous materials (including wood) to typical background levels, (c)
the removal of settled spores, and (d) reducing moisture to levels that do
not support microbial growth. The American Conference of Governmental Industrial
Hygienists (ACGIH) further states that the ‘Effective remediation of water–damaged or microbially contaminated buildings
involves (a) the use of appropriate techniques to promote rapid drying, and
(b) complete removal of contaminated materials rather than the application
of biocides without these steps’ (ACGIH Bioaerosols: Assessment
and Control - publication #3180).”
Microbial growth, in small isolated
areas, that has occurred in a surface layer of condensation on painted
walls or nonporous surfaces (including wood) can usually be removed by (a)
HEPA vacuuming if dry, (b) washing the area with a dilute solution of biocide
or a mild detergent, or (c) cleaning, thorough drying and repainting. Porous
materials that have sustained more extensive microbial growth must often be
removed.
Again,
according to the S500 Standard “When microbial growth is confined to a larger
area of the structure, effort must be made to prevent the dissemination of
spores to uncontaminated areas and to protect the occupants from exposure.
Preventive measures may include, but are not necessarily limited to:
§
posting warning signs;
§
turning off the HVAC system until the contaminated material
is removed;
§
erecting local containment in the contaminated area, if feasible;
§
sealing off air vents and doorways;
§
wrapping contaminated debris in 6-mil plastic during removal;
§
HEPA vacuuming surfaces before, during and after the removal;
and
§
using air filtration devices (AFDs).
These steps reduce spore delivery to
unaffected areas of the structure and greatly reduce the spread of fungal
growth. During remediation, workers must wear appropriate personal protection
equipment (PPE).
In extensive mold remediation projects
(32 SF or more), additional consideration must be given to: containment, establishment
of decontamination chambers, control of air flow due to pressurization relationships;
HEPA filtration of the air space and supply air in the HVAC system; dust control;
detail cleaning to remove visible dust and debris; sampling before and after
procedures, and work progress monitoring as part of quality assurance.
Additional information regarding
mold remediation may be obtained from other organizations including, but not
necessarily limited to: AIHA and ACGIH. It is highly recommended that technicians
consult with knowledgeable indoor environmental experts who may include indoor
environmental (IE) consultants, industrial hygienists (IHs) or environmental
health professionals (EHPs).”
How to Find Qualified Remediation Firms
It is essential, when searching for
qualified firms, that you ask about industry affiliations such as the Water Loss Institute (WLI), a division
of the Association of Specialists in
Cleaning and Restoration (ASCR International), and that water damage technicians
have been certified with the Institute
of Inspection, Cleaning and Restoration Certification (IICRC)". The
Water Loss Institute has created an advanced designation course for their
membership. Those that successfully complete the course, pass the all day
exam and submit a project report and research paper receive the designation
of Water Loss Specialist (WLS). For information on the Water Loss Institute
or Water Loss Specialists in your area, call ASCR headquarters at 1-800-272-7012,
or visit their web site at: http://www.ascr.org.
For a computerized IICRC registrant referral directory call 1-800-835-4624.
For information on trained remediation
companies contact Restoration Consultants
at (916)-736-1100 or visit the website at http://www.restcon.com/.
This article does not take into consideration all of the procedures that
may be required in a restorative drying project. It also does not address
all of the issues about mold remediation. You can purchase a copy of the IICRC
S500 Standard and Reference Guide by contacting the IICRC at (360)-693-5675.
For information about the application of the S500 Standard you can contact
Restoration Consultants, (916)-736-1100. Dri-Eaz Products, Inc. has published
a manual entitled “Restorative
Drying" that discusses this subject in detail. You can purchase a
copy of the manual by contacting Dri-Eaz at 800-932-3030.
ACGIH American Conference of Governmental Industrial Hygienists
AIHA American Industrial Hygiene Association
ASCR Association of Specialist in Cleaning and Restoration
IICRC Institute of Inspection of Cleaning and Restoration Certification
WLI Water Loss Institute
WLS Water Loss Specialist