Association of the Wall and Ceiling Industry Logo

Indoor Air Quality Issues In Commercial Buildings

Although regulations abound governing handling of asbestos and lead-based paint during renovation and construction, there are no federal standards for mold testing and no state laws or regulations regarding mold. A number of state and federal agencies, along with professional environmental consulting firms, make recommendations regarding mold cleanup. The following bulletin from ATC Associates, Inc. discusses mold assessment techniques in commercial buildings.

Across the United States, property managers, building owners, banks and insurance companies are being confronted with what is becoming a multi billion dollar problem: mold. Approximately 9,0000 lawsuits claiming property damage, personal injury and related losses due to toxic mold have been filed in the United States and Canada during the past 10 years, according to National Underwriter Property and Casualty-Risk & Benefits Management. In 2001, mold cost insurance underwriters more than $1.3 billion, based on an estimate from The Environmental Educator. Foundation in St. Paul, MN. The Foundation estimated that awards for such claims are running between $200,000 and $400,000.

Many of the largest settlements and jury awards have involved commercial buildings. The discovery of what has been called “toxic” mold in the workplace has forced employers to seal offices or relocate workers and has spawned a wave of personal injury claims

against building contractors, architects,
owners and property managers. In San
Martin, Calif., for example, the Santa
Clara County Courthouse was temporarily
closed due to mold, forcing
employees into trailers for temporary
offices. A lawsuit alleging building deficiencies
against the building’s general
contractor, architect and others ended
up being settled for $12 million, reported
USA Today. In Stuart, Fla., the Martin
County Courthouse was closed and
completely gutted after mold was discovered.

The county sued the construction manager and was awarded a $14
million jury award to cover cleanup and
other costs. In Bartow, Fla., the Polk
County Courthouse was forced to spend
$30 million to correct problems that lead
to microbial infestation.


Mold and mildew can be found anywhere
that a moisture problem exists. It
grows on any organic substance including
wood, paper, carpet, foods and insulation.
According to the Environmental
Protection Agency, some problems have
been linked to building construction
practices during the past 30 years, which
have resulted in more tightly sealed buildings
that may not allow moisture to
escape. Reduced ventilation rates to save
energy is another contributing factor.

Although most indoor air contaminants
do not have a serious impact on the
healthy work force, problems can occur
when fungi such as Stachybotrys and
Aspergillus become concentrated, producing
airborne allergenic spores and
mycotoxins. These irritants can affect the
respiratory system, resulting in symptoms
such as watery eyes, runny nose and
sneezing, nasal congestion, itching,
coughing, wheezing and difficulty
breathing, headache and fatigue. Severe
exposure can result in pneumonia, central
nervous system damage, and even cause cancer, according to an article in
Occupational Health & Safety.

In one office location in Sacramento,
Calif., a broken water pipe resulted in an
infestation of toxic molds at 2,200 times
the levels found outside the building,
according to Occupational Health &
Safety. Workers at that business developed
spontaneous nosebleeds and respiratory
infections. The business was forced
to relocate, and the building’s property
manager was sued.

$30 million to correct problems that lead
to microbial infestation.
Mold and mildew can be found anywhere
that a moisture problem exists. It
grows on any organic substance including
wood, paper, carpet, foods and insulation.
According to the Environmental

signs of mold include leaky windows,
condensation on sills, paint and wallpaper
delamination, stained carpeting, presence
of multiple portable humidifiers and
standing water in air conditioning or
refrigerator drip pans.
Under some conditions, mold may grow
on hidden surfaces, such as the backside
of drywall, wallpaper or paneling, on the

In an office tower in New Orleans, hundreds
of office workers became ill when
water damage caused a mold infestation.
Employees experienced rashes, runny
noses and breathing problems so severe
that some had to bring oxygen to meetings,
according to USA Today Employees
filed a class-action lawsuit against the
building’s owner and the state of New


Unlike asbestos or lead-based paint, there
are few regulations governing indoor air
quality contaminants. There are no current
state or federal regulations dictating
the requirements of mold investigations.
This lack of standardized, circumscribed
requirements and protocols allow for
variability in the way microbial assessments
are performed on any given project.
Typically, an initial investigation of
the affected site is conducted to determine
the presence and extent of fungal
colonization of building materials due to
water damage.

When inspecting buildings for signs of
mold growth, moisture, leaks or spills,
the EPA recommends checking for musty
odors, water stains or discoloration on
the ceiling, walls, floors and windowsills.
Inspectors also should check in restrooms,
around and under sinks for standing
water, water stains or mold. Other tell-tale
signs of mold include leaky windows,
condensation on sills, paint and wallpaper
delamination, stained carpeting, presence
of multiple portable humidifiers and
standing water in air conditioning or
refrigerator drip pans.

Under some conditions, mold may grow
on hidden surfaces, such as the backside
of drywall, wallpaper or paneling, on the
top of ceiling ties, or on the underside of
carpets and pads. Vinyl wallpaper covering
drywall may act as a vapor barrier,
trapping moisture underneath its surface,
creating a moist environment for mold to
grow in. Other locations can include pipe
chases and utility tunnels with leaking
or condensing pipes, walls behind bookshelves and casework where condensation
forms, and inside ductwork. Under these
conditions, the EPA recommends seeking a
professional with experience in conducting
mold assessments.


Recommended protocols for the collection
of environmental samples have been
published in the American Industrial
Hygiene Association Field Guide (1996),
the American Conference of
Governmental Industrial Hygienists
Bioaerosals: Assessment and Control
(Macher, 1999), and the National
Institute for Occupational Safety and
Health Manual of Analytical Methods,
(1994, with update supplements).
Typically, collection of environmental
samples may not be necessary when fungal
contamination is readily observable.
Odors considered to be related to the release
of volatile organic compounds by
molds may trigger a need for sampling
to determine if reservoirs of hidden mold
The EPA recommends that sampling for
mold be conducted by professionals with
specific experience in designing mold
sampling protocols, sampling methods
and interpretation of results. Type of

samples listed by the EPA include air
samples that can be analyzed by direct
microscopic examination for total spore
counts (called a spore trap method), surface
samples, bulk samples (chunks of
carpet, insulation, wallboard, etc.), and
water samples from condensate drain
pans or cooling towers. Use of moisture
meters also can determine the presence,
location and extent of water damaged
building materials. Moisture mapping
of a water-damaged area can delineate
areas that require drying and potentially
delineate mold-contaminated areas.
Hidden mold generally is inspected by
destructive methods that include removing
a portion of the wall and performing
a visual inspection, or collecting
bioaerosol samples through a small hole
drilled in the wall. Another method uses
a borascope, which is a specially designed
flexible, fiber-optic probe with a light
source to perform a visual inspection by
being inserted into a wall system through
a drilled hole.


Architects, contractors, insurance companies
and building managers are looking
for a safe and financially viable solution
to the problems of water intrusion
and the resulting microbial growth.
Proactive planning is necessary to make
buildings less susceptible to moisture
problems during the design and construction
phases and to respond to
unavoidable moisture problems that may
occur. Some insurance companies and
owners now require Operations &
Maintenance Plans for moisture control
and water damage response.

Time is the critical element in responding
to water intrusion and moisture
issues. What begins as an inexpensive
drying process if responded to within 24
hours, if left unattended, can develop
into a mold contamination problem that
has health implications, disrupts business
and requires expensive remediation.
Key elements to an O&M plan for
microbial and moisture management
include the following:

  • Establishing and explaining objectives,
    both short term (stop the water and
    dry the damage) and long term (prevent
    the water intrusion).

  • Identifying responsible individuals,
    including project leadership, appropriate
    consultants and response/drying
    remediation contractors, architects
    and construction contractors.

  • Creating response plans for various
    water intrusion scenarios.

  • Scheduling regular maintenance and
    defining inspection requirements.

  • Developing supply checklists for
    HVAC, building envelope and grounds

During construction and renovation, the
O&M plan provides guidelines to prevent
water intrusion, including the following:

  • Timing of building envelope completion.
    (In one recent case, lack of sealed
    windows permitted gypsum board and
    insulation to become wet.)

  • Reviewing site drainage and completion
    issues. (On one recent project,
    storm drains were covered, which
    caused a flood that damaged nearby
    finished rooms.)

  • Maintaining dry storage areas for sensitive building materials. (At one site,
    insulated ductwork was stored on the
    floor where it was damaged by rain

  • Maintaining reasonable humidity conditions
    during construction. (Mold
    problems have occurred at some sites
    after carpets or gypsum board were
    installed in cold basements during
    periods of high humidity without

  • Designing HVAC air intakes to minimize
    water entry, sewer gas entry, minimize
    ponding from poorly drained
    condensate drains and sloped roofs.


Remediation of mold/fungal growth or
contamination requires a focused
approach to identify mold growth problems
and to develop the appropriate measures
for removal. A typical scope of work
might include visual inspections, bulk
and air sampling and analysis, identification
of viable and nonviable spores,
work plans for mitigation, decontamination,
ambient air monitoring, remediation
oversight and clearance testing
to evaluate final project area spore levels.
Early detection and appropriate remedial
action is the key to a cost-effective

Two documents that address remediation are Mold Remediation in Schools
and Commercial Buildings
, March
2001, EPA and Guidelines on Assessment
and Remediation of Fungi in Indoor
, New York City Department
of Health, 2000. These guidelines
are designed primarily for building
managers, custodians and other personnel
responsible for building maintenance.

Cleanup methods range from use of wet
vacuums, to removal of contaminated
building materials and furnishings. Once
water damage has occurred, it is important
to find the cause of moisture infiltration
and fix it, then remove and restore
affected building materials. In hiring a
remediation contractor, the following
factors should be considered:

  • Insurance.
  • Business history and references.
  • Affiliation with reputable industry
    organizations (Disaster Kleenup
    International, National Air Duct
    Cleaners Association).

  • Licensed, where applicable.
  • Written proposal.
  • Follows state-of-the-art practices and
    guidelines (NYC, EPA, ACGIH guide-lines).

Always define the roles of the contractor,
owner and/or third-party evaluator
and clarify details such as cleaning methods,
chemicals to be used, limitations
and exclusions in the scope of work and
clearance criteria. The EPA recommends
scheduling remediation activities during
off-hours when building occupants are
less likely to be affected. According to
EPA guidelines: “In some cases, especially
those involving large areas of contamination,
the remediation plan may
include temporary relocation of some or
all of the building occupants. The decision
to relocate occupants should consider
the size and type of the area affected
by mold growth, the type and extent
of health effects reported by the occupants,
the potential health risks that
could be associated with debris, and the
amount of disruption likely to be caused
by remediation activities.”

About the Author

Bob Arritt is director, Industrial Hygiene,
in ATC’s Omaha, Neb., office. He brings
more than 12 years of expertise in
asbestos/lead abatement, indoor air quality,
construction management and hazardous
materials remediation.

For More Information

To contact the author, write to 3712 S.
132nd St., Omaha, NE, 68144, or call
(402) 697-9747.

The Foundation also has made available
three publications on the subject of
mold. The first is Mold: Cause, Effect
and Response. The second is Preventing
Losses from Moisture and Mold During
Construction. The third in the research
series is Mold Litigation: Prevention and
Defense. Copies are available for $10
each by calling (703) 534-8300, or they
can be downloaded for free from

Browse Similar Articles

You May Also Like

A truckbed full of T2Earth product.
ByT2EARTH® is a science-based manufacturer of sustainable, toxic-chemical free, fire-retardant and superior-performance forest building materials.
Young boy plays on drum kit at home. Elderly man irritated by noisy neighbor, screams, knocks on the wall. Low level of sound insulation. Apartments separated by thin wall.
We may take this for granted, but we all experience reality through our five senses, not the least of which is our sense of hearing.
AWCI's Construction Dimensions cover

Renew or Subscribe Today!