Signs of Mold Infestation
Many mold problems are often overlooked
by simply not recognizing early warning
signs. In some instances, a small amount
of mold on a surface is nothing more
than what it seems. Other times it can
be an indication of a much bigger
Destruction from hidden mold can be
significantly limited, if not completely
prevented, by acting sooner rather than later. Periodic inspections of your home or
place of business and an awareness of early
warning signs of mold infestation can often save
thousands of dollars in costly repairs. Take a
look around your property. If you see any of the
following warning signs, call AMI for a
thorough, professional mold inspection.
STAINS ON WINDOW SILL
STAINS ON WINDOW CASE
STAINS ON EAVES
STAINS AT ROOF LINE
STAINS ON STUCCO
Properties with indoor
mold problems typically display one or more of
1. High Humidity - A relative humidity
level of greater than 55% promotes the growth of
mold and other fungi.
2. Water/Pipe Leaks - Many mold problems
originate from water and pipe leaks since they
are often undetected for days, months, or even
years if minor enough.
3. Flooding - Mold problems are very
common after flooding. It usually requires
several days or weeks to fully dry out a
structure, giving colonies of black mold more
than adequate time to grow.
4. Mildew or Musty Odors - Odors can
often be the first or only sign of a potential
mold problem. In some cases, moldy smells will
only be evident when the air conditioning or
heat is turned on, indicating growth within the
5. Increased Allergy or Respiratory Symptoms
- Suffering allergic reactions in your home
or building could be due to the presence of high
levels of mold, especially if other signs are
6. Signs of Toxic Poisoning - Toxic black
mold and other fungi produce Volatile Organic
Compounds (VOCs). Exposure to high levels of
VOCs may irritate the mucous membranes and the
central nervous system leading to symptoms of
headaches, decreased attention span, difficulty
in concentration, and dizziness.
7. Leaky Roof - Like other types of water
leaks, water intrusion through the roof is
difficult to find until it is too late. If you
suspect a leaky roof, check in the attic for
signs of water damage or mold growth.
8. Use of Humidifiers without Relative
Humidity Control - Using humidifiers can
easily raise the moisture level in the air to
the point where mold is able to grow at a rapid
rate. When using a humidifier, the key is to
regulate the relative humidity level, to ensure
it stays within 55-60% RH.
9. Damp Basements or Crawl Spaces -
Basements and crawl spaces tend to receive less
ventilation (especially crawl spaces), and are
more likely to be neglected than other parts of
the home, so mold can grow undeterred for a
longer period of time.
10. Condensation or Rusting -
Condensation on or around pipes, windows, or
walls is a sign of a leak or high humidity.
Rusting on pipes in particular, and anything
else metal, is also a sign of a high humidity
problem or nearby leak.
11. Lots of House Plants - House plants
require consistent watering, which increases
moisture levels inside.
12. Discoloration of Walls (Water Stains) -
Yellowish stains on walls and ceilings are a
sign of excessive moisture. You may also notice
places where the paint is coming off due to
moisture, where drywall is "bowing" out, or
where nail heads are rusting through.
13. Cracked, Peeling Paint - This usually
means that there is moisture build up behind the
paint. By the time the paint shows these signs,
the moisture has often had an opportunity to
spawn the growth of mold within the wall.
14. Blocked Gutters - Gutters that are
blocked can cause water to seep into walls
through the roof and can cause water to collect
at the base of the foundation.
15. Warped Wood - If wooden materials in
your home have been infiltrated by enough water
to actually warp, then sufficient levels of
moisture are probably present to accelerate mold
16. Black Growth in Bathroom Tiles - Tile
grout is porous and will allow water
penetration, and mold growth behind the tiles
themselves. In addition, dirt and other grime
(favorite foods of mold) are easily trapped in
the grout - an ideal environment for mold to
17. Loosening or Bubbling of Drywall Tape - This is a
sure sign that moisture has infiltrated the
18. Visible Biological/Mold Growth - This
may seem like an obvious sign, but many people
do not take a little visible mold growth very
seriously. However, this can be an indication of
a much larger mold growth in less visible
19. Clothes Dryers and Other Appliances Not
Vented Outdoors - If the steam from these
types of appliances is vented inside, then this
significant amount of additional moisture
creates a great environment for mold to
20. Poor Ventilation - If the air
pressure in your home is "negative", meaning the
air pressure outside is greater than it is
inside, then it will force moisture and
contaminates back into the home. If the air
pressure is well into the "positive" side, then
it can cause moisture to be forced into walls.
The air pressure in your home should be slightly
positive or at least balanced.
21. Presence of Wet Materials Indoors -
This can include rags, steam from cooking,
indoor clothes lines, carpet, or furniture. If
these or other items are damp for extended
periods of time, then the moisture level can be
high enough to accommodate mold growth.