Page 392 - Construction Waterproofing Handbook

9.2 CHAPTER NINE
health issues. Mold is actually fungi, which are organisms that obtain food by absorbing
nutrients from external sources rather than through an internal digestive system. Fungi
release digestive enzymes that break down the food source, which then can be absorbed
back into the fungi as they grow.
Molds reproduce by releasing tiny spores into the air that land on surfaces that can pro-
vide a food source (e.g., organic building materials such as drywall) and a moist environ-
ment. Almost all molds can be detrimental to people with respiratory and asthma
problems, including the common black mold, Stachybotrys chartarum. This type mold is
often found in bathrooms, typically around shower walls, growing on the organic grout
materials in the warm and moist environment.
Most molds are generally nontoxic, and we encounter them everyday outdoors as part
of nature’s way of degrading and disposing of materials such as tree leaves. Some molds
actually are beneficial, the most well-known being penicillin. This mold produces a waste
product known as an antibiotic.
More serious are molds that produce hazardous waste products called mycotoxins.
Mycotoxins are poisons produced by certain fungi or molds. The common black mold
described earlier also can produce mycotoxins, as evidenced by the amount of press cov-
erage given to the subject recently. Molds and mildew that produce mycotoxins can create
a large variety of health problems from asthma to even life-threatening conditions. It is this
concern that mandates that all mold and mildew growth should be prevented in all build-
ing structures regardless of whether it is the type that produces mycotoxins or not.
There are in fact so many different types of molds and fungi (estimates as high as over
500,000) that actual identification of the type of mold and whether it is toxic or not should
not be a priority. Rather, the immediate emphasis should be on mold remediation and
remedial waterproofing to prevent the water source that provided the opportunity for the
mold to grow in the first place.

TESTING FOR MOLD

Usually mold is identified easily by visual examination; it is often located near or at the
source of water infiltration. For example, mold growing on drywall around widow frames
is very common in residential construction when the widows have not been installed using
the recommended techniques for transitioning from the building cladding to the window
frame and sealant along the window frame has been applied improperly.
Mold also often is identified by a musty smell, and then procedures must be undertaken
to identify the location, which might involve removing architectural finishes such as car-
pet, wallpaper, tile, etc. to expose the mold contamination. In many cases, certain archi-
tectural finishes must be removed to expose the areas of mold, such as pulling back
wallpaper to uncover the drywall that is infested with mold growth. Removal of sufficient
finishes to determine the complete extent of the mold infestation is required to prepare the
area for actual mold remediation.
In extreme situations, where the mold source cannot be readily identified and located,
air testing may be required. Air testing for the presence of mold must be done by experi-
enced professionals and can be extremely expensive. Air testing is often required in office