Other than just having a high humidity
level in the home (due to humid climate), water leaks
and other forms of water intrusion into the home or building
is the most common reason a toxic black mold problem originates.
Below are types of water leaks and places where unwanted
water can enter the home, and ways to avoid these types
of water intrusion problems. Leaking Pipes: Condensation
or rusting on or around a pipe is a sign of a leak. Covering
cold surfaces, such as cold water drainpipes, with insulation
helps to prevent condensation. The most difficult part
of preventing leaking pipes is determining whether or
not they are leaking in the first place, since they are
normally concealed from view. Here are some signs to look
for:
1. You can hear running water sounds when nothing is turned
on.
2. Musty odors that seem to originate from walls or floors.
3. Running toilets and dripping faucets.
4. Abnormally high water bills.
5. A water meter reading that changes when you aren?t
using any water for an hour.
6. Discolored or damaged walls.
7. A cracked or damp foundation or slab.
8. Warm spots on concrete slab floors, mildew, or excess
moisture under carpets.
9. Regular sewer backups.
10. Areas in the yard that are too wet and with unusual
plant or grass growth.
To prevent water from collecting around the foundation,
and seeping up through the walls, make sure the ground
slopes away from the foundation. Here are some additional
tips in preventing water seepage through the foundation:
1. Ensure the floor is well ventilated and walls are properly
sealed against moisture entry. Polythene put over damp
ground can help prevent dampness rising into the house.
2. Insulate your home properly. In the winter, insulated
ceilings, walls and floors have temperatures similar to
those of the warmer air inside the home, therefore condensation
is less likely to form.
3. Prevent rising damp from entering a foundation wall
by improving your home?s perimeter drainage. Direct all
surface rainwater away from the home through drainpipes,
culverts, French drains, etc.
4. If no other methods are feasible, a last resort would
be to install either a physical or chemical horizontal
damp-proof course.
Ways to Inspect for a Roof Leak. A common cause of leaks
is from cracked or damaged chimneys. Look for loose brick,
cracked mortar joints, and a solid metal or concrete cap
on top. Look for water stains on the inside ceiling, and
on the beams in an attic. Beams that have been exposed
to water will become weakened and cause a sag in the roof.
Look for any visible damage such as cracks, tears, splits.
These will most likely lead to leaking. Closely inspect
all roof penetrations (i.e. skylights, chimneys, vents,
etc). Look for signs that the cement is separating from
the surface, especially at a vertical penetration of the
roof. Check areas where different materials meet such
as metal to brick, shingles to metal, etc. These surfaces
expand and contract at varying rates and will pull away
from each other. Make sure the seals between materials
are tight, not loose. You can attempt to find a leak from
the inside by using a flashlight and tracing the leak
uphill.
How to Protect/Maintain the Roof. Inspect your roof at
least twice a year. Especially proceeding harsh weather
conditions and between seasons. Roofs will weather under
the heat/sunlight. It can essentially be ?baked? and become
dry and brittle (alligatoring), hence it is more likely
to split and eventually leak. Metal components of the
roof can rust and corrode, and asphalt-based plastic cement
used for seals around pipes, vents, and other penetrations
may deteriorate over time and leak. You can apply a coating
to some roofs to create a layer of waterproof protection.
Ice Dams and Leaks. Leaks caused by ice dams occur when
warm, heated air from the home begins to migrate through
the insulation and into the attic area of the house. Without
proper ventilation, this warm air collects in the attic
area and may warm the underside of the roof decking. Cold
outside temperatures keep the top outside layer of moisture
frozen and the warm decking melts the bottom layer of
ice turning into liquid water. This water will run down
the shingles until it meets the "dam" at the gutter line.
With no escape route, the water pools, then backs up underneath
the shingles and enters the attic area through nail holes
and seams in the roof decking .
Ways to Minimize the Occurrence of Ice Dams.
Keep the attic adequately insulated. Do not cover the
attic soffit air intake vents with insulation (add these
to your home if you don?t have any). Ensure attic has
sufficient air exhaust outlets and airflow is distributed
evenly throughout the attic (peak mounted ridgevents maximize
air flow). An ice and water shield can be installed at
the eaves of the home and under the shingles to prevent
water from entering the home. Install electric heat tapes
in the gutter system. Windows: Condensation on or around
the window is the sign of a excessive moisture. If this
is happening, use a sealant around the window to make
sure that it is completely air tight. Walls: Taking measures
to reduce water leakage through the roof, leaky pipes,
and the foundation (see above for each of these), as well
as through the gutters (below) will go a long way in keeping
the walls from collecting too much moisture. In addition
to this, make sure that the air pressure is not too high
on the positive side (see Ventilation tips below). However,
you do want the air pressure inside to be slightly positive.
Also, make sure that the relative humidity level is below
55% to prevent your walls from taking in too much moisture
(Relative Humidity Sensor Buying Guide). Use dehumidifiers
if necessary.
Gutters: Clogged or faulty rain gutters can cause excessive
water leakage through the walls, roof, and foundation
of the home. You can clean your rain gutters with a light
broom, a garden hose with a controllable-spray nozzle,
or by using one of many gutter-cleaning devices on the
market. Adding perforated covers over your rain gutters
will cut down on the frequency of cleaning.
Rainwater and some dirt/small debris can permeate the
cover but large debris, such as large leaves and twigs,
cannot. These covers can typically be found in a local
hardware store for only a couple of dollars for about
every 4-feet of length. Make sure your gutters' downspouts
are properly cleaned too. Spray water into the gutter
or the top of the downspout to ensure it drains freely
and with no obstructions. Water must also be diverted
away from your home's foundation. If you don't have a
spout going directly into a drain system in your yard
and toward the street or a drainage basin, use splash
blocks. These relatively small devices will channel the
water from your downspout and away from your home and
only cost a couple of dollars. Basements/Crawl Spaces:
Click here for more on basements and crawls spaces. Basements
/ Crawl Spaces
Put a plastic cover over dirt in crawlspaces to prevent
moisture from coming in from the ground. Be sure crawlspaces/basements
are well ventilated with good cross ventilation under
the house so air will circulate freely. Make sure all
vents are unobstructed and repair any torn vent screens.
If you don?t have sufficient vents, add more. .
Drainage system. An effective exterior drainage system
drains bulk water away from the foundation. A channel
of coarse rock or drainage tile may be used. The drainage
system must be installed on the outside, and near the
bottom of the footing
Foundation wall insulation. Foundation insulation may
be placed on the exterior wall, be an integral part of
the wall, or placed on the interior of the foundation
wall. Regardless of where the insulation is placed, a
moisture barrier is required to reduce outdoor moisture
from coming through the foundation wall. In the case of
insulation placed on the interior side of the foundation
wall, both sides of the insulation must be protected.
A moisture barrier is required between the insulation
and the wall from floor to grade, and a vapor retarder
is required on the interior side of the insulation.
To keep water out of crawlspaces, dig ditches around the
sides of the house down to the footing. Install gravel
and drain lines that are sloped about
2 inches per 10 feet to carry water away from the house.
Direct the water to a natural drainage, to the street,
or a French drain. Before backfilling, place waterproof
membranes against the foundation wall. Also, ensure water
from downspouts is directed away from the house.
Ductwork / HVAC System Sanitize Cooling Coils Make sure
you periodically wipe any biological growth from the coils.
Condensation is continually dripping off the coils when
the HVAC system is running. This condensation provides
a perfect place for mold to grow. In which case, disinfectant
should be periodically applied to the coils. Drain Pan
This is where the condensation from the cooling coils
drips. If you have a flat drain pan, the stagnant water
will become infested with mold growth. In which case,
a sloped drain pan should be used, so the water runs off
to the proper location. You also need to check to make
sure that drain lines are flowing properly. In addition,
the drain pan should be cleaned with a disinfectant on
occasion, and should be replaced when corrosion becomes
significant.
Filters Change your HVAC filters on a regular basis. If
this is not done, the filter itself can become a fertile
breeding ground for all the molds and other biological
contaminates that are collected. Once this happens, the
spores from the mold will multiply, and will be circulated
throughout the home or building through the ductwork.
Insulation If you have insulation lining the interior
of the ductwork, then it should be removed, so you are
left with bare sheet metal. The fiber glass insulation
collects a lot of dirt and dust, which provides a good
habitat for mold colonies. Once the mold begins to grow
inside the ductwork, the mold spores will be spread throughout
the house when the HVAC system is running.
Cleaning Mold in the HVAC System New Construction In many
cases, mold problems can be avoided or caused during the
construction of a home or building. In which case, you
can take precautions during this phase to save yourself
mold headaches down the road. First, review many of the
tips on this page to make sure that the house is built
in such a way that as many of these as possible can be
put into place. In addition, avoid using moldy materials,
ensure that any fake stucco that is used is installed
100% properly, since this is a common cause for mold growth
in exterior wall cavities. If you are really adamant about
preventing potential mold problems, then you may want
to avoid using fake stucco altogether.
Dirt / Dust Removal An environment that is "dirty" or
"dusty" is far more conducive to mold problems than a
clean environment. Dirt, dust, and grime are often composed
of organic material, which is a staple of the the toxic
"black" mold diet. House dust also serves as a means for
locomotion for mold spores, enabling them to spread throughout
the home more effectively. Ventilation Proper ventilation
can reduce moisture in the home. Keeping the air pressure
in the home or building at a slightly higher level than
the air pressure outside will help to ensure proper ventilation.
Slightly positive air pressure forces moisture and contaminates
outside. If the air pressurization is the other way around
(negative), where the air pressure is higher outside,
then it will force moisture and pollutants back into the
home or building. Avoid over-pressurization though (too
much of a positive air pressure), since it will cause
moisture to be forced into walls and structural cavities,
compounding the moisture level inside, and potentially
damaging the home or building. In order to achieve a slightly
positive air pressure, adjust the supply ventilation slightly
higher than the exhaust ventilation. Also, try to ventilate
appliances and bathroom/kitchen fans outside if possible.
Properly Vent Combustion Appliances Combustion appliances
include space heaters, ranges, ovens, stoves, furnaces,
fireplaces, water heaters, and clothes dryers. Typically
these appliances are safe. However, the combustion process
always produces water vapor, if the appliance is not properly
vented, it can lead to increased amounts of moisture in
the home and provide an ideal environment for mold growth.
Examples of properly venting combustion appliances include
equipping ranges with hood fans that are exhausted to
the outside, keeping doors open to rooms where these appliances
are operating, making sure that the vents are connected
and unblocked, and that there are no holes or cracks in
the ventilation systems. Finally, make sure that you follow
manufacturer instructions when installing and using combustion
appliances.
Keep Firewood Outdoors Firewood often has a little mold
growth on it before being brought indoors, since it contains
nutrients for mold to grow and thrive. This is not a problem
if kept outdoors, but the mold growth can really progress
if the firewood is kept in contained areas. Shower Curtains
Replace shower curtains when mold begins to become visible.
Air Purification You may want to use an air purifier to
minimize the airborne particulate, which allows mold spores
to disperse to other areas of the home or building. To
neutralize something as difficult as mold, an air purifier
with multiple technologies is needed (Air Purification
Buying Guide). HEPA filters and ionizers combine to effectively
capture the allergenic spores released into the air (HEPA
stands for High Efficiency Particulate Arrestor). Germicidal
UV light purification is also important to destroy the
toxic micro-organisms associated with mold.
