Diagnostic Methods and A/E Design Solutions. Greg Baker, CIH, CSP, CHMM AMEC Earth & Environmental, Inc.

Transcription

1 Diagnostic Methods and A/E Design Solutions Greg Baker, CIH, CSP, CHMM AMEC Earth & Environmental, Inc. October 17, 2006

2 Three Questions Why Does Mold Grow in Building Envelopes? How Do You Deal With Mold? How Do You Design To Avoid Mold?

3 Why Does Mold Grow in Building Envelopes? Too Much Water! In the liquid state In the vapor state In the solid (ice) state transitioning to liquid and insufficient means to prevent, inhibit, control, manage and remove excess moisture

4 Why Does Mold Grow in Building Envelopes? Failure to prevent and control excess moisture Poor design: By design buildings are Inadequate planning, material sequencing, etc Circumstances / poor choices

5 Why Does Mold Grow in Building Envelopes? Insufficient construction management Inadequate QA/QC Insufficient commissioning Lack of proper maintenance And.inadequate or untimely responses

6 How Do You Deal With Mold? Resolve moisture issues Remove suspect visible mold and debris following established guidelines (i.e., the standard of care)

7 How Do You Deal With Mold? Proactively

8 How Do You Deal With Mold? Proactively Risk = Hazard + Outrage Tomoko Kurauchi Age 115

9 How Do You Deal With Mold? Plan ahead to prevent moisture & mold Manage construction activities (CM) Include 3 rd party inspections & verification

10 How Do You Deal With Mold? Follow applicable building codes Implement BMPs appropriate for the macro and micro-environments Include preventive I & M programs in terms of sales and leases

11 Identifying The Proximate Cause(s) of Mold Growth Related to Moisture Intrusion We are better at identifying causation because we have: Better understanding of why construction and installation practices fail Better understanding of how and why various construction materials and products fail

12 Identifying The Proximate Cause(s) of Mold Growth Related to Moisture Intrusion We are getting better at identifying causation because we have: Better understanding of how lack of maintenance contributes to failures Better equipment to detect failures

13 Infrared Thermography Chronic Firewall Moisture (purple areas below white line)

14 Photograph 25: Firewall completed section. Note moisture profile. Photograph 26: Firewall section opened. Note mold on fire resistant GWB. Inspection holes cut by contractor.

15 Infrared Thermography Missing Insulation Balcony Header Moisture

16 Infrared Thermography Balcony Door Leak

17 Flashing Detail Brick to Roof Flashing Detail at Balcony Headers

18 Balcony attachment to house. Note leak.. Interior leak in area of balcony. Note paint blistering and peeling.

19 Identifying The Proximate Cause(s) of Mold Growth Related to Moisture Intrusion We are getting better at identifying causation because we have: Greater appreciation for rapid response with regards to water losses We are further along on the defects learning curve

20 What conditions promote Moisture Humidity Temperature Carbon Oxygen Time mold growth?

21 What building related factors exacerbate mold growth? Water intrusion Building defects Design defects Product defects Maintenance Occupant lifestyles Catastrophic events Ventilation; infiltration and exfiltration

22 What building related factors exacerbate mold growth? Condensation Latent moisture Vapor transport Pressurization Topography Hydrostatic pressure Drainage

23 Moisture Intrusion-Wall Assembly Latent Moisture Drainage Problems Capillarity Thermal Bridging Condensation Defects allow Liquid Transport Defect Defect Air movement and vapor transport Vapor pressure and diffusion Convection (Stack Effect) and vapor transport

24

25 Moisture Intrusion-Pitched Roof Assembly Defects allow Liquid Transport Condensation and Dew Point Inadequate Ventilation Dryer venting not adequate Defect Potential for ice jams Blown-in insulation covers bird screens

26

27 A bathroom fan exhausting into an attic crawlspace.

28 Moisture Intrusion-Foundation Assembly Latent Moisture from Construction Poor Drainage Vapor Pressure Hydrostatic Pressure Capillarity Thermal Bridging Condensation Defects allow Liquid Transport Defect

29 Faulty Vapor Barrier

30 Moisture Intrusion-Foundation Assembly Building Constructed on Filled Wetland Poor Drainage Unfavorable Topography Soils with low Permeability Blocked or plugged foundation vents Stressed vegetation Parking Lot Storm sewer Improper installation Sump pump failure Dryer exhaust broken

31

32 Bad Sump Pump

33 Moisture Intrusion-Foundation Assembly on Daylight Basement Condensation and Dew Point Hydrostatic Pressure Poor Drainage Vapor Pressure Poorly conceived downspouts Parking Lot Slab on grade Concrete foundation extends above soil level

34

35 Summary What we just covered Why some buildings fail by design Why some construction and installation practices fail How and why various construction materials and products fail How the lack of maintenance contributes to failures Some new equipment in use to detect failures Why rapid response to water losses is critical Why we know more about predicting defects and anticipating damaged conditions than we used to

36 For more information: Greg Baker, CIH, CSP, CHMM AMEC Earth & Environmental, Inc