MOLD AND MILDEW REMEDIATION OPERATING PROCEDURES
Mildew contamination
in commercial buildings, institutions and households alike continues
to receive increased attention in the media and is a rapidly growing
concern for homeowners, property managers, insurance companies,
and restoration companies. Without proper mitigation of an indoor
moisture occurrence, mildew can start to grow in as little as
48 hours, and contamination has been identified as a major contributor
to building-related illness and poor indoor air quality. Despite
the rapidly growing body of knowledge about mildew, it remains
the subject of a lot of confusion. While ServiceMaster does not
claim to have all the answers, we hope that this information will
help you to make better decisions.
PART
ONE
What Is Mildew?
We have probably all encountered mold and mildew at one time or
another. It might have been mildew in the shower, or mold on a
stale piece of bread, or mildew on some wet drywall. Mildew develops
into mold. Mold is a microscopic life form found in all parts
of the world. It is part of the natural decay process of organic
materials. There are many different species of mold/mildew and
while they are diverse, they share some common characteristics:
- Mildew
requires an organic food source. A common source is cellulose,
found in building materials such as drywall.
- Mildew
requires oxygen, so it does not grow under water.
- Mildew
requires a constant supply of water. To prevent mold, buildings
must be kept dry.
- Mildew
is spread by tiny particles called spores. A spore can be
compared to a seed.
Why is
mildew harmful?
Mold and mildew cause problems for several reasons:
- The coloured,
fuzzy mildew growth on the contaminated surface is obviously
very objectionable.
- Active
mildew colonies usually emit a very unpleasant, musty odour.
- Because
the job of mildew is to digest, decay and recycle dead organic
matter, it destroys whatever surface is its host.
- Exposure
to mildew spores can cause mild to severe allergic reactions,
and possibly more serious problems, depending on individual
sensitivity.
What is
a reasonable and safe response to mildew?
The best way to deal with mildew is to prevent it from happening.
If wet building materials are dried within 24 hours (assuming
clean water), the chances of preventing growth are excellent.
If the area remains wet, mildew will start to grow. Therefore,
addressing and eliminating the moisture problem is the most important
first step to mitigation. But once present, drying is not enough.
Moldy materials must be either removed or decontaminated. This
process is called remediation, and means “to remedy” or “to cure”.
Proper remediation procedures are determined by the size, scope
and nature of the contamination.
Three integral
principles form the framework for remediation: containment, removal
and safety. Containment is the practice of sealing or separating
the affected area to keep spores from spreading and causing mildew
to grow in previously uncontaminated areas. Temporary walls of
plastic or plywood may be erected to separate the affected area
from the rest of the building. This area is called the containment
zone. Air machines equipped with high efficiency particulate arresting
(HEPA) filters are used to pull outside air into the containment
zone and exhaust filtered air to the outside. These machines are
sometimes called air scrubbers and this process is called negative
air flow. Removal of mildew and mildew-contaminated materials
must also be done in a manner that prevents further contamination.
Most importantly, these procedures must be performed in a way
that protects the remediation technicians, as well as the occupants
of the building from potentially harmful exposure.
