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Moisture Control Guidance for Building Design, Construction and Maintenance

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Moisture Control Guidance for Building Design, Construction and Maintenance EPA 402-F-13053 | December 2013 | www.epa.gov/iaq/moisture Moisture Control Guidance for Building Design, Construction and Maintenance Indoor Air Quality (IAQ) Indoor Air Quality (IAQ) Moisture Control Guidance for Building Design, Construction and Maintenance U.S. Environmental Protection Agency December 2013 www.epa.gov/iaq/moisture Contents Foreword: How to Use this Guidance ................................................................................................ v Acknowledgements ............................................................................................................................ vi Chapter 1 Moisture Control In Buildings ................................................................................................................... 1 Introduction ..................................................................................................................................... 1 Health Implications of Dampness in Buildings ..................................................................................... 1 Moisture Damage in Buildings ............................................................................................................ 2 Moisture Problems are Expensive ........................................................................................................ 7 How Water Causes Problems in Buildings ............................................................................................ 7 Moisture Control Principles for Design ................................................................................................. 8 Moisture Control Principle #1: Control Liquid Water ............................................................................. 8 Moisture Control Principle #2: Manage Condensation ......................................................................... 14 Moisture Control Principle #3: Use Moisture-Tolerant Materials ........................................................... 19 The Basics Of Water Behavior ................................................................................................................ 24 Chapter 2 Designing for Moisture Control ............................................................................................................... 26 Introduction ................................................................................................................................... 26 Designing Effective Moisture Controls ............................................................................................... 26 Building Commissioning .................................................................................................................. 26 Who Should Read this Chapter ......................................................................................................... 27 Site Drainage .................................................................................................................................. 28 Foundations ................................................................................................................................... 32 Walls ............................................................................................................................................. 38 Roof And Ceiling Assemblies ............................................................................................................ 45 Plumbing Systems .......................................................................................................................... 54 HVAC Systems ................................................................................................................................ 57 iii Chapter 3 Constructing to Prevent Moisture Problems ............................................................................................... 67 Introduction ................................................................................................................................... 67 Pre-Construction Planning ................................................................................................................ 71 Site Drainage Construction ............................................................................................................... 74 Foundation Construction .................................................................................................................. 76 Wall Construction ............................................................................................................................ 78 Roof and Ceiling Assembly Construction ............................................................................................ 80 Plumbing System Installation ........................................................................................................... 82 HVAC System Installation ................................................................................................................. 84 Chapter 4 Operating and Maintaining Moisture-Controlled Environments ...................................................................... 87 Introduction ................................................................................................................................... 87 Site Drainage Maintenance .............................................................................................................. 90 Foundation Maintenance .................................................................................................................. 92 Wall Maintenance ........................................................................................................................... 93 Roof and Ceiling Assembly Maintenance ........................................................................................... 95 Plumbing System Operation and Maintenance ................................................................................... 98 HVAC System Operation and Maintenance ......................................................................................... 99 Appendix A - The “Pen Test” .......................................................................................................... A-1 Appendix B - Roof Inspection Checklist ........................................................................................ B-1 Appendix C - Testing Moisture During Construction .................................................................... C-1 Appendix D - Air Pressure Mapping .............................................................................................. D-1 Appendix E - HVAC Inspection Checklist ...................................................................................... E-1 Appendix F - Site Drainage Maintenance ......................................................................................F-1 Appendix G - Dampness & Mold Evaluation ................................................................................. G-1 Glossary ............................................................................................................................................ H-1 iv www.epa.gov/iaq/moisture Foreword: How to Use this Guidance This document was developed by the U.S. Who Should Read this Guide Environmental Protection Agency, Indoor Environments Division. It provides practical guidance This guide can be used by anyone who designs, on how to control moisture in buildings.1 It is not a builds, operates or maintains buildings and heating, textbook, code or standard. ventilating and air conditioning (HVAC) equipment. It was developed specifically for: Chapter 1 focuses on principles of moisture control: • Professionals who design buildings and produce how water moves into and within a building and drawings, specifications and contracts for why the movement of water should be controlled or construction or renovation. managed. Chapters 2, 3 and 4 provide profession- specific guidance for the design, construction and • Professionals who erect buildings from the maintenance phases of a building’s life. To illustrate construction documents. how core concepts and principles relate to each stage • Professionals who operate and maintain buildings, of a building’s life, each guidance chapter contains conducting preventive maintenance, inspecting the hyperlinks to relevant principles described in Chapter landscape, building interior and exterior equipment 1 and other related material throughout the text. Each and finishes and performing maintenance and guidance chapter also includes methods for verifying repairs. the appropriate implementation of the moisture control recommendations and a reference section that identifies additional related resources for readers interested in more detailed information. 1NOTE: This document does not address flood water control. For information about managing flood water, see http://www.epa.gov/naturalevents/flooding.html or http://www.epa. gov/naturalevents/hurricanes/. Accessed on November 6, 2013. v www.epa.gov/iaq/moisture Acknowledgements The United States Environmental Protection Agency, Office of Radiation and Indoor Air, Indoor Environments Division would like thank the many professionals who contributed to this document, including Terry Brennan and Michael Clarkin of Camroden Associates and Lew Harriman of Mason-Grant Consulting. The Agency would also like to thank Christopher Patkowski for permission to use the photograph of water droplets on the front and back covers. The figures in
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