Transcript Assessing and Remediation of Moisture and Mold in Residential Housing July 19,2003 The Building Performance Center.

Assessing and Remediation of
Moisture and Mold in
Residential Housing
July 19,2003
The Building Performance Center
What is mold?
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Biological Pollutant
 A living organism
 Can grow on almost
anywhere and on any
surface
 Needs food,
temperature and
moisture to grow
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Mold or Fungi
 Multi-cellular
and unicellular
 Multi-cellular formed of microscopic
filaments called HYPHAE
 A colony looks velvety, granular or leathery
 May appear black, red, green, yellow or
brown
 Most common aspergillus, pennicilium,
and stachybotrys.
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Mold and Fungi
 Outdoors
mushrooms, puffballs, truffles
 During lifecycles spores are formed
 Spores small, light, travel by air
 Need food from external sources
 Water is critical to digestive process
 Volatile compounds can be released called
mycotoxins
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Mold and Fungi
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Grows on organic
materials
 Wood
 Paper
 Foods
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Health Effects of Mold
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Allergenic
 Pathogenic
 Toxigenic
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Allergenic Molds
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Allergic reactions to mold are common
Inhaling or touching may cause allergic
reactions to sensitive individuals
Mold can be dead or alive
Repeated exposure may cause sensitivity
Symptoms include Hay fever reaction, sneezing,
runny nose, red eyes, skin rash
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Pathogenic Molds
 Cause
infections
 Only small group of molds associated with
infections
 Most dangerous for immune compromised
individuals
 Some infections include Hypersensitivity
Pneumonitis, Histoplasmosis
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Toxiogenic Molds
 Cause
disease
 Exposure thru inhalation, ingestion and
skin contact
 Mycotoxins
 Some molds have been proven to cause
liver damage, central nervous system
damage
July 19,2003
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Building Science Basics
 Moisture
Flow Concepts
 Air Flow Concepts
 Indoor Air Quality Concepts
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Liquid Flow
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Driven by gravity or
air pressure
 Examples: roof Leaks
and plumbing leaks
 The most serious
threat for a home
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Capillary Flow
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Liquid water creates a suction of its own as it moves
through tiny spaces within and between building
materials
Examples: Capillary action can also move liquid water
into a home through damp soil and a porous concrete
slab or stem concrete wall
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Air Movement
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Air movement carries water vapor into and out of
the building and it’s cavities
 Example: Hot air rises through the cracks and
crevices in the top of the building shell taking
water vapor with it.
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Vapor Diffusion
 Water
vapor will move through solid
objects depending on their permeance and
vapor pressure
 Is the the slowest form of moisture
movement
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Moisture Rules
 Moisture
moves from warm to cold
 Moisture
flows from more to less
 Moisture
hitchhikes with air:
high pressure to low pressure
 Gravity pulls water down
 Water wicks up
l
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Air Flow Basics
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Air Flow
1 Cfm out = 1 Cfm
in
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Air Flow
High pressure flows to
low pressure
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Air Flow
A hole + a driving force
=Airflow
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Driving Forces
Natural
Mechanical
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Wind
 Stack Effect
Bath Fans
 Kitchen Fans
 Dryers
 Forced air heating
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IAQ Basics
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Most vulnerable to the effects
of indoor air pollution
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Elderly
Children
Disabled
Immune deficient or
chronically ill
Pregnant
woman/unborn child
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Children the most vulnerable
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Their bodies are still developing.
Their immune systems are still developing and may be less
protective
They take in more food, water and air per pound of body weight than
adults
They are smaller and therefore closer to pollutants on or near the
ground.
They put their hands in their mouth more than adults
Early environmental insults may have a lifelong consequences
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Indoor Air Pollutants
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Moisture
Pressed wood furniture
Moth repellents
Dry cleaned goods
Dust mites
Personal care products
Car exhaust
Paint supplies
Paneling
Radon
Tobacco smoke
Carpets
Insects
Household chemicals
Pesticides
Lead based paint
Woodstove
Pets
Cleaners
Products of combustion
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Seven Steps to a Healthy
Home
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Dry and Clean
Water, clutter and dust permit or encourage the growth of mold, insects rodents and
mites. Keeping a home dry and clean controls mold and pests.
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Well ventilated
Ventilation provides a mechanism to remove contaminants.
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Combustion Product Free
Combustion products like carbon monoxide should not be present in a healthy home
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Seven Steps Cont.
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Toxic Chemicals Free
Toxic cleaning compounds, pesticides, oil based paints and solvents can lead to poor indoor air
quality.
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Pest Free
Pests lead to allergic reactions and pests lead to pesticides. Food and water
lead to pests.
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Comfortable
Uncomfortable homes can make people take action that makes a home unhealthy. If
people can’t afford to heat their home they won’t ventilate their home.
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People
Pollutants
Pathways Pressures
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Review
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Mold spores are everywhere
Mold needs a temperature range from 40’F to
100’F to grow
Mold needs food to grow
Mold needs moisture to grow
Mold can cause moderate to severe reactions
Mold is a symptom of a moisture problem
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Assessing for Mold and
Moisture Problems
 Procedures
for assessments
 Guidelines for assessments
 Tools for assessments
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Procedure for Assessing
Mold and Moisture
 Client
interview
 Pollution Source Survey
 Physical survey of the building
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Client Interview
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Very valuable in
assessing a IAQ problem
May have a complaint
that should be recognized
Often know a lot about
their home
A chance for further IAQ
education
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Pollution Source Survey
 Documents
existing conditions
 Can indicate possible problems
 Identifies risks
 May help in designing solutions
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Pollution
source
survey
Pollution
source
survey
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Physical Survey
 Survey
possible moistures sources from
outside and document
 Examples
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Physical Survey
 Survey
possible sources from inside and
document
 Examples
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Assessment Tools and
Measurements
 Eyes,
ears, nose
 Measure relative humidity
 Measure building materials moisture
content
 Measure surface temperatures
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Measuring Relative Humidity
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Thermo-Hygrometer
homeowner model
 Digital
 $19
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Measuring Relative Humidity
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Sling Psychrometer
 For measuring RH
takes 2 minutes
 $35
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Detecting Moisture
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Pin tester
The process requires
making holes in the
material to tested
Works on wood,sheetrock
,plaster, concrete
$350
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Detecting Moisture
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Non destructive tester
 Slides across material
to be tested without
damaging it
 $200 to $400
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Measuring Temperature

Infrared Pointer
 Measures common
surface temperatures
 $350
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Guidelines for Evaluating
Mold Contamination
 New
York City Guidelines
 CMHC Homeowners Guide
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Small Areas
 NYC
defines as 10 sq ft or less designated
LEVEL 1
 CMHC defines a “small area” no larger
than one sq meter and no more than three
of those areas
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Small Areas
 NYC
remediation conducted by trained
maintenance staff
 Training includes clean up methods,
personal protection and potential health
hazards
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Small Areas
 CMHC
say homeowners can clean up with
detergent and gloves and dust mask and
guidance from Homeowners’ Guide
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Mid-Sized Areas
 NYC
defines as 10-30 sq ft. designated as
LEVEL 2
 CMHCC considers mid sized to be more
than three patches, each smaller than a sq
meter or there is one or more isolated
patches larger than a square meter but
smaller that three sq meters
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Mid-Sized Areas
 NYC
remediation conducted by trained
maintenance staff
 Training includes clean up methods,
personal protection and potential health
hazards
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Mid-Sized Areas
 CMHC
recommends assessment by a
professional but if proper procedures are
followed can be cleaned up by the
homeowner
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Large Areas
 NYC
defines as 30-100 sq ft
 CMHC considers an single patch greater
than sheet of plywood “extensive
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Solving Problems
 Mold
is the outcome of another problem
 MOISTURE
 Solve the moisture problem and you solve
the Mold problem
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Moisture Sources
 Interior
 Exterior
 Quantifying
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Moisture contributions from
inside
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Respiration, perspiration
4pints / person / day
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Moisture contributions from
inside
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Unvented dryers
 5.0 pints / load
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Moisture contributions from
inside
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Plants
 .96 pints / day / 7
plants
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Moisture contributions from
inside
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Crawlspaces
 0 to 105 pints / day
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Moisture contributions from
inside
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Firewood
 0-5 pints / day
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Moisture contributions from
inside
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Dishwashing
 .044 / pints / day / 4
people
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Moisture contributions from
inside
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Showering,bathing
 .52 pints / 5 minutes
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Moisture contributions from
inside
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Floor mopping
 .03 pints / sqft
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Moisture contributions from
inside
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Cooking
 .088 pints / day / 4
people
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Moisture contributions from
inside
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Plumbing Leaks
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Moisture contributions from
inside
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Drying laundry inside
 4-6 pints per load
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Standing water in crawl space
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Moisture from outside
 This
can be the largest source of moisture
in a house
 Roof leaks
 Broken or disconnected gutters and
downspouts
 Improper site drainage
 Broken footing drains
 Improperly functioning landscape irrigation
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Roof Leaks
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Improper flashing details
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Site Drainage
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Disconnected Downspout
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Broken Footing Drains
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Moisture Problems are either
 A surface
temperature problem or
 A vapor pressure problem
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Common Surface
Temperature Problems
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1.
2.
Poor air circulation
Closets
Exterior corners
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Common Surface
Temperature Problems
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1.
2.
Wind washing and Low insulation levels
Exterior wall line at ceiling
Near leaky windows or doors
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Solving problems
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1.
2.
Reduce vapor pressure
Source control
Dehumidification
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Psychrometric Basics
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Dry Bulb Temperature
 The
air mixture temperature as measured
by an ordinary thermometer
 It is plotted as a family of lines along the
x-axis
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Absolute Humidity
 The
ratio of actual amount of moisture in
grains of water per pound of dry air
 Absolute humidity ratio is plotted on the yaxis of the chart
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Relative Humidity
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Relative humidity is the ratio of the amount of moisture in
the air compared to the maximum amount of moisture
the air could contain at the same temperature and
pressure.
It is a family of curved lines that slope upward from left to
right
100 % relative humidity line is called the saturation curve
and it forms the boundary on the left side of the chart
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Wet Bulb Temperature
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Wet bulb temperature is another measurement of the
amount of moisture in the air.
Measured with a wetted cotton wick placed over the bulb
of a thermometer.
As the wick evaporates it lowers the reading on the
thermometer due to evaporative cooling.
The lower the amount of moisture in the air, the lower will
be the wet bulb temperature because a higher rate of
evaporation will occur in dyer air.
These values are shown along the saturation curve.
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Dew Point Temperature
 It
is the dry bulb temperature at which
condensation first occurs as heat is
removed from the air.
 The dew point is found by moving
horizontally along the chart from the given
point to the saturation curve.
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Enthalpy
 It
is the total amount of heat contained in
the air mixture
 Enthalpy is plotted as a family of diagonal
lines on the chart that slope upward from
right to left.
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Specific Volume

Is a measurement of the volume occupied by the
air based on it’s weight.
 It’s measured in terms of cubic feet per one
pound of dry air.
 Specific volume is is plotted as a family of
diagonal lines that slope sharply upward right to
left.
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Psychrometrics Exercise #1
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Psychrometrics Exercise #2
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Psychrometrics Exercise #3
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Mold and Rot
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MOLD
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Mold
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More Mold
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Mold
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