Most of the following is referenced from the IICRC
S520 Standard and Reference Guide for Professional Mold
Remediation. Read it.
It is very important
to have negative air established in containment. This is not
simply to prevent cross contamination but to capture dust generated
during demolition. Where as there may only be a few Stachybotrys
mold spores in the air prior to remediation, thousands of spores are
aerosolized by simply removing a square inch of moldy sheet rock
from a stud. An air scrubber in scrubber mode is not effective.
- There should
be pressure drop of 0.02 inches of water in the containment with
reference to outside the containment, and a minimum of four air
exchanges per hour inside the containment (IICRC section
10.3.1). The number of air scrubbers required to do this should
be calculated using the square footage and volume of the
containment area, and expecting for some reduction in air flow
as filters become loaded. The supervisor should check the
integrity of the containment and measure and document the
- Draw make-up
air from a clean source.
pre-filters of air scrubbers and negative air machines should be
monitored for pressure drops
from construction dust and replaced as necessary.
scrubbers being used as negative air machines that are not
exhausted to the outdoors should be checked with a laser
The exhaust should read nearly zero particles.
Place tacky mats
near entry to the containment area.
be striped from the structure so as not to excessively agitate them
and unnecessarily spread spores and dust (IICRC
10.8 Removal of Contaminated Structural Materials).
- Do not use a
hammer to demolish drywall.
- Unscrew or
carefully pry gypsum board away from studs.
- Use razor
knives or specially fitted skill saws.
- If saws are
used, set the saw blade such that the blade does not penetrate
all the way through the paper backing of the gypsum board and
finish removal by scoring the backing with a razor. This keeps
dust out of wall cavities.
- Do not use
any methods that would raise dust such as dry sweeping or
vacuuming with equipment not equipped with HEPA filtration.
saws should have dust collection devices.
drywall may be covered with plastic and duct-tape prior to
cutting and removal to contain debris including mold spores.
removed materials in 6 mil plastic bags. Do not stack materials in a
pile on the floor, waiting until there is a large pile to bag them.
The work area is to be kept as clean and free of debris as possible.
Periodically HEPA vacuum and damp wipe the containment area (IICRC
section 10.9 Detailed Structural Cleaning). HEPA vacuum and damp
wipe the containment area at the end of each work day. In
restaurants, the saying is Clean as you go; the sign of a good cook
is a clean kitchen.
Any rot should be
While sanding or
wire-brushing materials, hold the HEPA vacuum near the brush or
sanding to capture the dust generated. Place the intake of the air
scrubber or negative air machine in close where the sanding or
brushing is being done.
When there is water
damage or visible mold on one side of a wall, the drywall on the
other side should also be removed also, even if there is no visible
mold on the other wall. Often mold is hiding between sill plates and
drywall when mold growth is not visible above the level of the sill
The method to use in
damp wiping is:
A clean rag shall be folded in quarters and dipped into the cleaning
solution (soap and water). The rags shall be wrung out to remove
excess moisture. The wiping surface of the rag shall be changed
after each pass across the material. Wipe-down rags may not
re-enter the cleaning solution. Exhausted rags should be stored in
plastic bags pending disposal or laundering.
Clean from top to bottom. Clean starting from the entry to the
containment towards the air scrubber (IICRC 10.9).
is discouraged for mold remediation (IICRC S520, p.81). The use of
biocides is of limited effectiveness in the treatment of water
damaged and microbial contaminated buildings. If the spores are
physically removed there should be nothing left to sanitize. The
sampling method used during post verification testing does not
differential between non-viable (dead) and viable spores. If any
amplification of spores is detected, the project may fail, even if
the spores are non-viable (dead).
Seal off the air
scrubber intake after turning the scrubber off to contain the spores
that are on filter surface (IICRC 10.6, Air Filtration Devices AFDS
Air scrubbers should
be turned off the night before testing and a complete damp wiping of
horizontal surfaces is performed first thing the following morning
to remove dust, which settled over the night.
and fans between jobs per company standard operating procedures.
Air washing is the
best way to clean semi-porous and non-porous items (contents). Take
the contents outside. Care must be taken with porous items (fabrics)
not to blow the spores deeper into the materials. All cleaning of
contents should start and end with a HEPA vacuuming.