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Assessing and Remediation of Moisture and Mold in Residential Housing

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Title: Assessing and Remediation of Moisture and Mold in Residential Housing


1
Assessing and Remediation of Moisture and Mold in
Residential Housing
2
What is mold?
  • Biological Pollutant
  • A living organism
  • Can grow on almost anywhere and on any surface
  • Needs food, temperature and moisture to grow

3
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.

4
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

5
Mold and Fungi
  • Grows on organic materials
  • Wood
  • Paper
  • Foods

6
Health Effects of Mold
  • Allergenic
  • Pathogenic
  • Toxigenic

7
Allergenic Molds
  • 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

8
Pathogenic Molds
  • Cause infections
  • Only small group of molds associated with
    infections
  • Most dangerous for immune compromised individuals
  • Some infections include Hypersensitivity
    Pneumonitis, Histoplasmosis

9
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

10
Building Science Basics
  • Moisture Flow Concepts
  • Air Flow Concepts
  • Indoor Air Quality Concepts

11
Liquid Flow
  • Driven by gravity or air pressure
  • Examples roof Leaks and plumbing leaks
  • The most serious threat for a home

12
Capillary Flow
  • 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

13
Air Movement
  • Air movement carries water vapor into and out of
    the building and its cavities
  • Example Hot air rises through the cracks and
    crevices in the top of the building shell taking
    water vapor with it.

14
Vapor Diffusion
  • Water vapor will move through solid objects
    depending on their permeance and vapor pressure
  • Is the the slowest form of moisture movement

15
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

16
Air Flow Basics
17
Air Flow
  • 1 Cfm out 1 Cfm in

18
Air Flow
  • High pressure flows to low pressure

19
Air Flow
  • A hole a driving force Airflow

20
Driving Forces
  • Natural
  • Wind
  • Stack Effect
  • Mechanical
  • Bath Fans
  • Kitchen Fans
  • Dryers
  • Forced air heating

21
IAQ Basics
22
Most vulnerable to the effects of indoor air
pollution
  • Elderly
  • Children
  • Disabled
  • Immune deficient or chronically ill
  • Pregnant woman/unborn child

23
Children the most vulnerable
  • 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

24
Indoor Air Pollutants
  • Moisture Tobacco smoke
  • Pressed wood furniture Carpets
  • Moth repellents Insects
  • Dry cleaned goods
    Household chemicals
  • Dust mites Pesticides
  • Personal care products Lead based paint
  • Car exhaust Woodstove
  • Paint supplies Pets
  • Paneling Cleaners
  • Radon Products of combustion

25
Seven Steps to a Healthy Home
  • 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.
  • Well ventilated
  • Ventilation provides a mechanism to remove
    contaminants.
  • Combustion Product Free
  • Combustion products like carbon monoxide should
    not be present in a healthy home

26
Seven Steps Cont.
  • Toxic Chemicals Free
  • Toxic cleaning compounds, pesticides, oil based
    paints and solvents can lead to poor indoor air
    quality.
  • Pest Free
  • Pests lead to allergic reactions and pests lead
    to pesticides. Food and water lead to pests.
  • Comfortable
  • Uncomfortable homes can make people take action
    that makes a home unhealthy. If people cant
    afford to heat their home they wont ventilate
    their home.

27
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28
Review
  • Mold spores are everywhere
  • Mold needs a temperature range from 40F to 100F
    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

29
Assessing for Mold and Moisture Problems
  • Procedures for assessments
  • Guidelines for assessments
  • Tools for assessments

30
Procedure for Assessing Mold and Moisture
  • Client interview
  • Pollution Source Survey
  • Physical survey of the building

31
Client Interview
  • 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

32
Pollution Source Survey
  • Documents existing conditions
  • Can indicate possible problems
  • Identifies risks
  • May help in designing solutions

33
Pollution source survey
Pollution source survey
34
Physical Survey
  • Survey possible moistures sources from outside
    and document
  • Examples

35
Physical Survey
  • Survey possible sources from inside and document
  • Examples

36
Assessment Tools and Measurements
  • Eyes, ears, nose
  • Measure relative humidity
  • Measure building materials moisture content
  • Measure surface temperatures

37
Measuring Relative Humidity
  • Thermo-Hygrometer homeowner model
  • Digital
  • 19

38
Measuring Relative Humidity
  • Sling Psychrometer
  • For measuring RH takes 2 minutes
  • 35

39
Detecting Moisture
  • Pin tester
  • The process requires making holes in the material
    to tested
  • Works on wood,sheetrock ,plaster, concrete
  • 350

40
Detecting Moisture
  • Non destructive tester
  • Slides across material to be tested without
    damaging it
  • 200 to 400

41
Measuring Temperature
  • Infrared Pointer
  • Measures common surface temperatures
  • 350

42
Guidelines for Evaluating Mold Contamination
  • New York City Guidelines
  • CMHC Homeowners Guide

43
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

44
Small Areas
  • NYC remediation conducted by trained maintenance
    staff
  • Training includes clean up methods, personal
    protection and potential health hazards

45
Small Areas
  • CMHC say homeowners can clean up with detergent
    and gloves and dust mask and guidance from
    Homeowners Guide

46
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

47
Mid-Sized Areas
  • NYC remediation conducted by trained maintenance
    staff
  • Training includes clean up methods, personal
    protection and potential health hazards

48
Mid-Sized Areas
  • CMHC recommends assessment by a professional but
    if proper procedures are followed can be cleaned
    up by the homeowner

49
Large Areas
  • NYC defines as 30-100 sq ft
  • CMHC considers an single patch greater than sheet
    of plywood extensive

50
Solving Problems
  • Mold is the outcome of another problem
  • MOISTURE
  • Solve the moisture problem and you solve the Mold
    problem

51
Moisture Sources
  • Interior
  • Exterior
  • Quantifying

52
Moisture contributions from inside
  • Respiration, perspiration 4pints / person / day

53
Moisture contributions from inside
  • Unvented dryers
  • 5.0 pints / load

54
Moisture contributions from inside
  • Plants
  • .96 pints / day / 7 plants

55
Moisture contributions from inside
  • Crawlspaces
  • 0 to 105 pints / day

56
Moisture contributions from inside
  • Firewood
  • 0-5 pints / day

57
Moisture contributions from inside
  • Dishwashing
  • .044 / pints / day / 4 people

58
Moisture contributions from inside
  • Showering,bathing
  • .52 pints / 5 minutes

59
Moisture contributions from inside
  • Floor mopping
  • .03 pints / sqft

60
Moisture contributions from inside
  • Cooking
  • .088 pints / day / 4 people

61
Moisture contributions from inside
  • Plumbing Leaks

62
Moisture contributions from inside
  • Drying laundry inside
  • 4-6 pints per load

63
Standing water in crawl space
64
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

65
Roof Leaks
66
Improper flashing details
67
Site Drainage
68
Disconnected Downspout
69
Broken Footing Drains
70
Moisture Problems are either
  • A surface temperature problem or
  • A vapor pressure problem

71
Common Surface Temperature Problems
  • Poor air circulation
  • Closets
  • Exterior corners

72
Common Surface Temperature Problems
  • Wind washing and Low insulation levels
  • Exterior wall line at ceiling
  • Near leaky windows or doors

73
Solving problems
  • Reduce vapor pressure
  • Source control
  • Dehumidification

74
Psychrometric Basics
75
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

76
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77
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 y-axis
    of the chart

78
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79
Relative Humidity
  • 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

80
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81
Wet Bulb Temperature
  • 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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83
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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85
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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87
Specific Volume
  • Is a measurement of the volume occupied by the
    air based on its weight.
  • Its 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.

88
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89
Psychrometrics Exercise 1
90
Psychrometrics Exercise 2
91
Psychrometrics Exercise 3
92
Mold and Rot
93
MOLD
94
Mold
95
More Mold
96
Mold
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