Journal of Testing and Evaluation Selected Technical Papers STP 1498 Condensation in Exterior Building Wall Systems JTE Guest Editors: Bruce Kaskel Robert J Kudder Journal of Testing and Evaluation Selected Technical Papers STP1498 Condensation in Exterior Building Wall Systems JTE Guest Editors: Bruce S Kaskel Robert J Kudder ASTM International 100 Barr Harbor Drive PO Box C700 West Conshohocken, PA 19428-2959 Printed in the U.S.A ASTM Stock #: STP1498 Library of Congress Cataloging-in-Publication Data Condensation in exterior building wall systems / JAI guest editors, Bruce S Kaskel, Robert J Kudder p cm (Journal of testing and evaluation selected technical papers; STP1498) Includes bibliographical reference and index ISBN: 978-0-8031-4471-2 (alk paper) Dampness in buildings Exterior walls Protection Waterproofing I Kaskel, Bruce S II Kudder, Robert J., 1945TH9031.C663 2001 2011006935 693.8’93 dc22 Copyright © 2011 ASTM INTERNATIONAL, West Conshohocken, PA All rights reserved This material may not be reproduced or copied, in whole or in part, in any printed, mechanical, electronic, film, or other distribution and storage media, without the written consent of the publisher Journal of ASTM International „JAI… Scope The JAI is a multi-disciplinary forum to serve the international scientific and engineering community through the timely publication of the results of original research and critical review articles in the physical and life sciences and engineering technologies These peer-reviewed papers cover diverse topics relevant to the science and research that establish the foundation for standards development within ASTM International Photocopy Rights Authorization to photocopy items for internal, personal, or educational classroom use, or the internal, personal, or educational classroom use of specific clients, is granted by ASTM International provided that the appropriate fee is paid to ASTM International, 100 Barr Harbor Drive, P.O Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9634; online: http://www.astm.org/copyright The Society is not responsible, as a body, for the statements and opinions expressed in this publication ASTM International does not endorse any products represented in this publication Peer Review Policy Each paper published in this volume was evaluated by two peer reviewers and at least one editor The authors addressed all of the reviewers’ comments to the satisfaction of both the technical editor(s) and the ASTM International Committee on Publications The quality of the papers in this publication reflects not only the obvious efforts of the authors and the technical editor(s), but also the work of the peer reviewers In keeping with long-standing publication practices, ASTM International maintains the anonymity of the peer reviewers The ASTM International Committee on Publications acknowledges with appreciation their dedication and contribution of time and effort on behalf of ASTM International Citation of Papers When citing papers from this publication, the appropriate citation includes the paper authors, ⬘⬘paper title’’, J ASTM Intl., volume and number, Paper doi, ASTM International, West Conshohocken, PA, Paper, year listed in the footnote of the paper A citation is provided as a footnote on page one of each paper Printed in Baltimore, MD May, 2011 Foreword THIS COMPILATION OF THE JOURNAL of TESTING and EVALUATION (JTE), STP1498, on Condensation in Exterior Building Wall Systems contains only the papers published in JTE that were presented at a symposium in San Antonio, TX, October 10–11, 2010 and sponsored by ASTM Committee E06 on Performance of Buildings The Symposium Co-Chairmen and JTE Guest Editors are Bruce S Kaskel, Wiss, Janney, Elstner, Associates, Inc., Chicago, IL and Robert J Kudder, Raths, Raths & Johnson, Inc., Willowbrook, IL Contents Overview Insulation Draws Water W B Rose vii Testing/Analysis Laboratory Tests of Window-Wall Interface Details to Evaluate the Risk of Condensation on Windows W Maref, N Van De Bossche, M Armstrong, M A Lacasse, H Elmahdy, and R Glazer 31 Moisture Damage in Vented Air Space of Exterior Walls of Wooden Houses T Umeno and S Hokoi Drying Characteristics of Spray-Applied Cellulose Fiber Insulation M Pazera and M Salonvaara Moisture Measurements and Condensation Potential in Wood Frame Walls in a Hot-Humid Climate T A Weston and L C Minnich 59 80 94 A Review of ASHRAE Standard 160—Criteria for Moisture Control Design Analysis in Buildings A TenWolde 119 Moisture Response of Sheathing Board in Conventional and Rain-Screen Wall Systems with Shiplap Cladding F Tariku and H Ge 131 Investigation of the Condensation Potential Between Wood Windows and Sill Pans in a Warm, Humid Climate G P Stamatiades, III 148 Case Studies Interior Metal Components and the Thermal Performance of Window Frames S K Flock and G D Hall 169 Controlling Condensation Through the Use of Active and Passive Glazing Systems A A Dunlap, P G Johnson, and C A Songer 187 Case Study of Mechanical Control of Condensation in Exterior Walls C M Morgan, L M McGowan, and L D Flick 226 Considerations for Controlling Condensation in High-Humidity Buildings: Lessons Learned S M O’Brien and A K Patel 247 Fenestration Condensation Resistance: Computer Simulation and In Situ Performance E Ordner 269 Improving the Condensation Resistance of Fenestration by Considering Total Building Enclosure and Mechanical System Interaction P E Nelson and P E Totten 286 Condensation Problems in Precast Concrete Cladding Systems in Cold Climates T A Gorrell Author Index Subject Index 299 315 317 Overview This STP represents the peer-reviewed papers first presented at the October 10–11, 2010 symposium on Condensation in Exterior Wall Systems in San Antonio, Texas, sponsored by ASTM E06 Building Performance, Subcommittee E06.55 Exterior Wall Systems The symposium and this STP represent the continued efforts of this subcommittee to exchange state-of-the-art knowledge through symposia on topics related to the performance of exterior wall systems Past symposia of this subcommittee include water leakage, repair and retrofit, faỗade inspection and maintenance, and performance of exterior wall systems Condensation in walls is a timely topic for ASTM E06 to address Advancements in building sustainability, energy efficiency, and new wall systems have progressed significantly in recent years, while the consequential changes in wall moisture behavior resulting from these advancements are less well understood Although the topic of condensation, per se, is not addressed in this subcommittees prior symposia, it has been a related topic in much of the work of this subcommittee and the ASTM E06 committee at large Numerous previous papers, available through ASTM, have addressed this topic Seminal manuals and prior symposia presented by ASTM E06, and ASTM committee C16 on Thermal Insulation, chaired solely or in part by Heinz Treschel, serve as background to our current work A sampling of those volumes includes: MNL 40 Moisture Analysis & Condensation Control in Building Envelopes - Treschel, ed 2001; MNL 18 Moisture Control in Buildings - Treschel, ed 1994; and STP 1039 Water Vapor Transmission Through building Materials and Systems Treschel and Bomberg, eds 1987 Manual MNL 40 described some of the now-established computer simulations for condensation control such as WUFI (ORNL/IBP) Given the now nine years time since that work was published, E06 believed that the stateof-the-art had advanced and that practical experiences have been gained from the use of analytical products that were presented in the 2001 manual This symposium provided the opportunity for leading scientists and practitioners to again advance the body of knowledge on the topic of condensation in exterior wall systems Beyond ASTM, organizations such as ASHRAE have offered longstanding input on the issue of condensation control Other organizations have grown more recently, such as BETEC; and USGBC along with their LEED certification system These organizations are interested, directly or peripherally, in the issue of condensation They too have offered recent workshops on the topic of condensation Code writing organizations such as IBC, in their energy code IECC, as well as their under-development green code, vii IgCC, are actively codifying issues related to condensation control, which were brought to light in prior ASTM publications and in the work of these other organizations E06 believed in presenting this symposium, that these current papers on condensation could have a similar impact in future building codes This STP is organized, in the same presentation as the October 2010 symposium, into two parts: Testing/Analysis papers that concentrate on testing/analysis of materials and mock-ups to predict and prevent condensation in common exterior wall systems and Case Studies papers that document condensation problems found in the real-world and their solutions In addition, there is one keynote paper by William Rose, which presents the history that has lead to the present state-of-the-art and some of the erroneous concepts that have advanced to today This paper sets the tone that common-place thinking does not well serve the industry, and when it comes to the on-going discussion of condensation control, new ideas, and concepts, the consistent application of the principles of physics and the use of appropriate analytical techniques need to be embraced Although not included in this STP, the symposium attendees also benefited from a first-day tutorial session offered by Wagdy Anis and Robert Kudder on condensation This primer provided the science of condensation formation and present technologies used to control its formation For those without this background, this tutorial served as necessary background for the technical presentations An ASTM symposium and STP are a team-effort, which warrants the recognition of those who spend much time and energy in their success First, recognition goes to the many unnamed reviewers who, solely to better the industry, spent many hours reviewing and re-reviewing the submitted papers ASTM and JTE efforts were spearheaded by Dorothy Fitzpatrick and Susan Reilly, respectively, with able assistance by Hannah Sparks and Christine Urso Upon Dorothy’s retirement, Mary Mikolajewski ably stepped in Finally, special recognition goes to WJE staffer, Amber Stokes, who assisted the Editors keep to the ambitious review and symposium schedule, and the numerous email correspondences necessary to pull this all together Bruce S Kaskel Wiss, Janney, Elstner Associates, Inc 10 S LaSalle Street, Chicago, IL Robert J Kudder Raths, Raths & Johnson, Inc 835 Midway Drive, Willowbrook, IL viii Reprinted from JTE, Vol 39, No doi:10.1520/JTE102972 Available online at www.astm.org/JTE William B Rose1 Insulation Draws Water ABSTRACT: In the late 1930s, an architect and two researchers created a version of hygrothermal building science for the United States that focused on moisture conditions in exterior materials during cold weather The version they created was partial, and it was biased: It highlighted the importance of vapor transport, while it obscured the importance of temperature impact They based their argument on the prevention of “condensation,” yet they failed to provide a definition of condensation sufficient for use as a performance measure or criterion They produced prescriptive recommendations that later became code requirements, and these prescriptions embodied the incomplete and biased nature of their analysis They supported their argument with a flawed and misleading analogy They and their followers left a legacy of consumer fear of ill-defined moisture effects in buildings and of designers assigning excessive importance to prescriptive measures Their version provides inadequate preparation for the anticipated re-insulation of millions of U.S buildings in the years to come This paper will provide a short description of the hygrothermal issues involved It will trace the development of the condensation version by Rogers, Teesdale, and Rowley and the efforts that followed up to 1952 It will explain the legacy and impact of this approach related to existing building re-insulation and professional practice in design and architecture It will propose a framework for reviewing the link between moisture control prescriptive requirements and performance outcomes KEYWORDS: condensation, moisture control, insulation Condensation In 1901, in the course of the design of the Minnesota State Capitol Building, the architect Cass Gilbert was in discussion with Mr Guastavino, a highly regarded supplier of ceiling tiles, and a Mr Butler, the contractor Gilbert’s notes indicate Manuscript received January 21, 2010; accepted for publication June 14, 2010; published online August 2010 Research Architect, Univ of Illinois at Urbana-Champaign, Champaign, IL 61820 Cite as: Rose, W B., ‘‘Insulation Draws Water,’’ J Test Eval., Vol 39, No doi:10.1520/ JTE102972 Copyright © 2011 by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959 GORRELL, doi:10.1520/JTE103017 305 with edge-to-edge insulation have improved thermal performance if the ties are of non-conductive material, such as plastic or fiberglass The author has not witnessed condensation problems with insulated sandwich panels; however, ribbed panels can have similar thermal/ condensation problems as conventional solid panels due to thermal bridging at the concrete ribs A properly designed and installed vapor retarder system also acts as an effective air barrier, and generally is the best solution to control interior air exfiltration and moisture transfer through a wall system A continuous gypsum wallboard assembly, with taped seams and sealed perimeter joints, can be an effective air barrier 关2兴 Examples of Design, Installation, and Occupancy Problems That Cause Condensation No Vapor Retarder/Air Barrier The most basic design error for precast clad buildings in cold climates is the omission of specifying a vapor retarder system where one is needed This occurs most commonly when the designer is not familiar with the potential for condensation in precast clad wall systems in cold and transitional climates Incomplete Installation of Insulation and Vapor Retarder A more common occurrence is the lack of continuity of the insulation or the vapor retarder, or both, at perimeter conditions of a wall Often, the design drawings not include the level of detail to delineate the vapor retarder membrane and specify that it must be continuous to and sealed against adjacent systems, such as floor and roof structures, and door/window framing When the building enclosure is constructed with these gaps in the insulation and vapor retarder systems, the lack of continuity allows for interior air to reach the precast panel, as shown in Figs and 8, and cause condensation Penetrations and Thermal Bridges Similar to the above, the items that penetrate through the vapor retarder must be sealed against air leakage, as shown in Figs and 10 In addition, protection should be taken against the penetrating element creating a thermal bridge that could result in condensation This is a common problem at precast anchors, which are typically large and penetrate the interior wall layers 关2兴, as shown in Fig 10 During Wintertime, the steel anchor exposed to the inside of the wall insulation may be colder than the dew point temperature of the interior air resulting in condensation on the cold steel Unanticipated Conditions The design drawings typically include the details that are found within normal “line of sight,” such as window jambs and heads, at floor lines, at column/wall 306 JTE • STP 1498 ON EXTERIOR BUILDING WALL SYSTEMS FIG 8—A view of an opening in gypsum wallboard at a window jamb detail adjacent to a precast panel The foil scrim vapor retarder is not continuous to the window frame, and the window perimeter joint is uninsulated The back face of the precast panel is visible and exposed to interior air flow FIG 9—The unsealed vapor retarder at electrical penetration allows bulk air leakage through the wall GORRELL, doi:10.1520/JTE103017 307 FIG 7—A view looking up through open ceiling tile at interface between window head frame and a precast panel above The foil scrim vapor retarder is not continuous to the window frame, and the joint above the window is uninsulated The bottom edge of the precast panel is visible and directly exposed to interior air flow intersections, etc Occasionally, a condition occurs at a location not considered during the design phase that causes a discontinuity of the insulation and/or vapor retarder and results in air leakage and condensation For example, Fig 11 is an example of a building specified with batt insulation between metal studs and polyethylene vapor retarder membrane at the exterior walls Unfortunately, a ventilated soffit condition typical throughout the building was not detailed at the locations where the precast cladding meets the adjacent curtain FIG 10—The unsealed vapor retarder at steel anchor penetration allows bulk air exfiltration to the precast panel In addition, the steel framing is uninsulated and will act as a thermal bridge across the wall insulation 308 JTE • STP 1498 ON EXTERIOR BUILDING WALL SYSTEMS FIG 11—A view looking up through an opening into a ceiling soffit revealed the interface between the curtain wall framing and the precast panels The precast panel was uninsulated and without a vapor retarder Interior air was able to reach the back face of the precast panels via the ceiling soffit wall system, and during construction, this resulted in missing insulation and vapor retarder at these interface locations This omission created a direct pathway for interior air to the precast panels and significant condensation damage occurred Not all such conditions can be reasonably foreseen during the design phase, but most can be addressed during construction if a building envelope quality control program or a building envelope commissioning program is in effect to help identify such deficiencies 关3兴 Window Placement Another form of condensation observed in precast clad buildings is at the interior surface of metal window frames, including thermally improved windows The accumulation of condensation water on the interior surfaces of the window frame is sometimes mistakenly attributed to water leakage through the window, or a failure of the windows thermal break system, when in fact the cause is related to either the design or installation of the window to the precast interface detail Generally, this type of condensation problem is caused by poor placement of the window assembly in relation to the precast panel, or by lack of thermal separation between the precast panels and the thermally improved portion of the window system All too often, the thermally improved metal window systems are specified to be inset completely within the thickness of precast panel cladding so that the interior portion of the window frame is directly adjacent to GORRELL, doi:10.1520/JTE103017 309 FIG 12—Thermally improved window jamb inset into precast panel with no insulation in the perimeter joint between window and precast panel Under given temperature differential, the interior surface of the window frame is below freezing and would likely exhibit condensation the precast panel In cold temperatures, the proximity of the cold concrete can reduce the temperature of the window frame below the dew point temperature of interior air To illustrate this scenario, a commonly observed thermally improved window jamb detail was modeled by using the THERM 5.2 heat transfer modeling program 关4兴, as shown in Fig 12 The window system was placed directly adjacent to a in 共152 mm兲 thick precast panel and no insulation was included in the window perimeter joint The model was analyzed at an exterior temperature of −10° F 共−23° C兲 and an interior temperature of 70° F 共21° C兲 If the interior air is at 30 % RH, the dew point temperature of the air would be 37° F 共2.8° C兲 The THERM model calculated the interior surface temperature of the metal window frame to be 29.9° F 共−1.2° C兲, which is less than the dew point Therefore, this scenario would result in condensation, likely in the form of frost, forming on the window frame Adding insulation to the window perimeter joint would improve the situation by increasing the temperature of the window frame by several degrees, as shown in Fig 13 Under some conditions, this added insulation alone may prevent condensation on the window frame However, repositioning the window inward to locate the thermal break of the window generally in line with the wall insulation vastly improves the performance of the window system and eliminates the likelihood of condensation on the window frame under normal conditions, as shown in Fig 14 Interior Moisture Levels Too High for Specified Systems This condition can be caused during the design phase by not specifying the proper vapor retarder system for the anticipated level of interior moisture and mechanical system requirements However, all too often, the real problem is the uncontrolled humidification of interior spaces by an inadequately designed and controlled HVAC system and especially by the occupant after the building is completed 310 JTE • STP 1498 ON EXTERIOR BUILDING WALL SYSTEMS FIG 13—Same configuration as Fig 12 with the addition of insulation in the perimeter joint, resulting in the interior surface of the window frame rising by several degrees Design and Construction Considerations To reduce or eliminate the potential for condensation in a precast clad building, the following design considerations should be considered • Design the exterior wall assembly to provide an interior air barrier to prevent the inside air from reaching outside of the wall insulation and to the back face of the precast panels This may be achieved with a vapor retarder membrane, or in some cases simply with continuous gypsum wallboard with sealed perimeters and joints 关2兴 • Determine if a vapor retarder system is necessary based on the climate zone of the building, the interior humidification requirements, and the local building code • Select the insulation and vapor retarder system that is most appropriate for the building The selection should take into account the cost impact and the constructability of the different systems as related to the skill level of the local construction industry The use of spray-applied, closedcell polyurethane foam to provide an airtight insulation envelope with integral vapor retarder characteristics is fast becoming the material of FIG 14—Window shifted inward to more closely align the window thermal break with the wall insulation, thereby dramatically increasing the interior surface temperature of the window frame GORRELL, doi:10.1520/JTE103017 311 • • • • choice for many projects, provided that the installed thickness of sprayapplied insulation can develop the vapor resistance required for the application The designer should keep in mind that fire-rating requirements in some jurisdictions requires that additional steps should be taken to protect or encapsulate this material in wall and roof assemblies Provide an appropriate level of drawing details to indicate the following: • Continuity of vapor retarder and insulation systems, including termination at wall openings These details should clearly show that vapor retarder membranes are sealed to window and door frames and not stop short in order to prevent internal air and vapor exfiltration 关3兴 • Penetrations are properly sealed, and in the case of steel members, insulated to prevent thermal bridging 关3兴 • Locate window systems to prevent the thermally improved portion of the windows from close proximity to cold wall components without adequate thermal separation • Consider the wall details that occur at locations other than the usual line of sight locations Cut the wall sections, both vertical and horizontal, above ceilings and through soffit areas to identify the problem areas that could lead to air leakage and condensation Provide mechanical systems that properly monitor and regulate the interior humidity conditions based on exterior temperatures Secondary drainage systems may be used to collect and drain incidental water at the back face of precast panels, but these systems may not be completely effective against condensation These secondary drainage systems typically consist of a gutter or reglet at the back of the precast panels to collect water and drain it to the exterior through weep tubes However, there is usually a portion of the panel below these gutters where condensation can form and flow down to the floor level where it travels across the fire/smoke seal and into the building In addition, when temperatures are cold enough that the condensation forms as ice, the weep tubes will also be frozen and will not drain During the construction phase, the project team should incorporate steps to identify and correct the potential air leakage and condensation conditions as follows: • Specify and perform a quality control program or building envelope commissioning program to inspect the installation of the exterior envelope systems and their components 关3,5兴 Particular examination should be performed at the interface between different systems and different construction trades • Specify and perform air leakage testing 关3兴 Initial testing should be performed during the building enclosure mock-ups to identify inadequacies in the design or construction prior to building-wide installation Thereafter, perform regular intermittent testing during construction at representative areas as determined based on the size and complexity of the building enclosure design • Upon completion of the exterior envelope for the building, consider 312 JTE • STP 1498 ON EXTERIOR BUILDING WALL SYSTEMS thermal infrared testing of the building enclosure to identify potential locations of air leakage or thermal gaps that may contribute to condensation before the interior finishes are applied • Once the building is occupied, the owner has the responsibility to maintain the building systems to prevent condensation as follows: • Monitor the interior environment and adjust accordingly to prevent humidity levels from exceeding the design parameters of the building enclosure systems • Maintain the insulation and vapor retarder systems and seals When alterations are made to the building components, the continuity of the insulation and vapor retarder systems should be carefully considered and remain intact Repairs of Existing Buildings For the existing precast clad buildings that are experiencing condensation problems, the resulting interior water damage is often mistakenly attributed to water leakage from the exterior An investigation of the problem area should be performed to determine if the condensation is the actual cause, and should include the following • Review of the design drawings to identify possible causes for either water infiltration or the potential for condensation • Determine the history and pattern of the observed water infiltration Water leaks or damage that occurs only during Wintertime, particularly after a thaw event, are likely due to condensation within the wall • Perform an inspection of the wall exterior for possible avenues of water leakage This may require water testing to confirm or deny that leakage from the exterior is occurring • Investigate the as-built wall construction by using inspection openings to identify pathways for air leakage Also, inspect vapor retarder terminations and seals, continuity of insulation materials, and internal signs of condensation or water leakage Pressurizing the building 共or specific building areas兲 and using a smoke pencil is useful to pinpoint air leaks • Measure interior temperature and RH levels to determine if they are possibly contributing to the condensation These measurements should be performed at the time of the condensation event If available, the historic HVAC data for the building 共temperatures and RH measurements兲 is also useful to determine the cause共s兲 for observed condensation Once a condensation problem is identified, the repair options can be studied Ideally, this would include removal of interior finishes to the extent necessary to fully repair or replace the insulation and vapor retarder systems, and sometimes that is the only effective solution However, more often than not, this extensive approach is either not possible, or is unnecessary The simplest solution may be modifying the mechanical systems, or the occupant’s habits, to reduce the moisture levels in the building In most cases, the repairs will need to include some removal of interior or GORRELL, doi:10.1520/JTE103017 313 FIG 15—A view looking up through a ceiling opening at spray foam insulation repair installed on the back face of a precast concrete panel The spray foam was applied to an overall thickness to serve as both insulation and vapor retarder, as well as an air barrier to seal openings in the wall system exterior finishes to expose and repair improper termination details of the insulation and vapor retarder, such as at windows, doors, and at ceilings or floors These repairs typically consist of adding supplemental insulation materials to complete the insulation envelope, and taping of gaps in the vapor retarder membrane As previously described, the use of spray-applied, closed-cell polyurethane foam is becoming a commonly used material in building walls, and this is especially true for remediation of condensation problems, as shown in Fig 15 In addition to its physical characteristics, the ability of the expanding foam product to be installed into tight joints and irregular openings, as well as its ability to bond with many building materials, makes this product well-suited to this application However, careful evaluation and design of the application and proper installation must be performed to provide an effective solution Where possible, it would also be prudent to perform and evaluate a trial repair prior to embarking on a widespread repair project A trial repair area should be selected to include representative areas of the wall system that have previously experienced condensation and are large enough to incorporate typical wall conditions 共joint conditions, interfaces with adjacent cladding systems, etc.兲 The repair design should be fully executed in the trial repair areas by using the same materials and techniques that would be used for a comprehensive repair program Depending on the configuration of the building and trial repair areas, a special perimeter detailing may be required to isolate the trial repair area from the adjacent wall to prevent inadvertent lateral air and water vapor flow that may adversely affect the test results The duration of a trial repair should typically include all seasons for which condensation has previously occurred, which for cold climate regions usually means a full Winter season The trial repair area should be regularly monitored throughout the duration of the test and compared with other wall areas to compare the relative improvement of the repaired wall areas 314 JTE • STP 1498 ON EXTERIOR BUILDING WALL SYSTEMS Conclusions Condensation problems in precast concrete clad buildings are a potentially significant and persistent problem that can result in extensive damage to building interior finishes and systems, especially in buildings with high interior RH levels However, the basic cause共s兲 for condensation can be understood and addressed Proper design and specification of insulation and vapor retarder systems can reduce the potential for condensation in new buildings This same care and attention to detail must be carried through the construction phase and even into occupancy practices Consideration should be given to quality control, exterior commissioning, and testing programs during the construction phase to verify the proper installation and performance of the specified systems After completion of the building construction, the monitoring of interior RH levels and maintenance of the building envelope systems should be performed by the owner Existing precast clad buildings displaying condensation problems can be repaired, but usually not without some level of invasive work that may be costly An investigation should be performed to determine if condensation is, in fact, the problem and if the cause is related to the detailing and construction, an improperly controlled level of interior RH, or possibly both Consideration should be given to the performance of trial repairs to measure the efficacy of a repair design prior to proceeding with large-scale and comprehensive repair programs References 关1兴 关2兴 关3兴 关4兴 关5兴 VanGeem, M G., Designer’s Notebook—Energy Conservation and Condensation Control, Precast/Prestressed Concrete Institute, Chicago, IL, 2006 Rousseau, M Z and Quirouette, R L., “Precast Panel Wall Assemblies,” Building Science Forum ’82, a series of seminars presented in major cities across Canada in 1982, 1982, National Research Council Canada, Ottawa, ON Lemieux, D J., Building Envelope Design Guide—Wall Systems, National Institute of Building Sciences, Washington, D.C., 2010, http://www.wbdg.org/design/ env_wall.php THERM 5.2/WINDOW 5.2 NFRC Simulation Manual 共July 2006兲 Lawrence Berkeley National Laboratory, Berkely, CA, Program software and user’s manual available at http://windows.lbl.gov/software/therm/therm.html Odom, J D., Designer’s Notebook—Avoidance of Mold, Precast/Prestressed Concrete Institute, Chicago, IL, 2008 STP1498-EB/May 2011 315 Author Index A Morgan, C M., 226-246 N Armstrong, M., 31-58 D Nelson, P E., 286-298 O Dunlap, A A., 187-225 E O’Brien, S M., 247-268 Ordner, E., 269-285 Elmahdy, H., 31-58 F Flick, L D., 226-246 Flock, S K., 169-186 G Ge, H., 131-147 Glazer, R., 31-58 Gorrell, T A., 299-314 H Hall, G D., 169-186 Hokoi, S., 80-93 J P Patel, A K., 247-268 Pazera, M., 59-78 R Rose, W B., 1-27 S Salonvaara, M., 59-78 Songer, C A., 187-225 Stamatiades, G P., 148-166 T Tariku, F., 131-147 TenWolde, A., 119-130 Totten, P E., 286-298 Johnson, P G., 187-225 L U Umeno, T., 80-93 Lacasse, M A., 31-58 M Maref, W., 31-58 McGowan, L M., 226-246 Minnich, L C., 94-118 Copyright© 2011 by ASTM International V Van De Bossche, N., 31-58 W Weston, T A., 94-118 www.astm.org STP1498-EB/May 2011 317 Subject Index G A active glazing control, 187-225 air leakage, 299-314, 31-58, 286-298 airflow, 247-268 glazed exterior wall systems, 187225 H B building, 119-130 built-in moisture, 59-78 C cavity ventilation, 131-147 cellulose fiber insulation, 59-78 cladding, 299-314 climate chamber, 80-93 condensation, 59-78, 226-246, 269-285, 187-225, 299-314, 148-166, 247-268, 1-27, 169-186, 94-118 condensation control, 187-225 condensation resistance, 286-298 CR rating, 269-285 high humidity, 187-225, 247-268 hospital, 247-268 HVAC interaction, 286-298 hygrothermal analysis, 187-225 hygrothermal characteristics, 80-93 hygrothermal performance, 131-147 I insulation, 1-27 interior exposure, 169-186 L laboratory testing, 31-58 M D decay, 148-166 design, 119-130 diffusive vapor transport, 286-298 E exterior walls, 226-246 modeling, 169-186 moisture, 119-130 moisture control, 1-27 moisture damage, 80-93 moisture transport, 59-78 mold, 119-130 museum, 247-268 N F fenestration, 269-285, 286-298 field-experiment, 131-147 Copyright© 2011 by ASTM International natatorium, 247-268 numerical analysis, 80-93 www.astm.org 318 P passive glazing control, 187-225 precast concrete, 299-314 R rain-screen wall, 131-147 S sill pan, 148-166 stain, 80-93 T THERM, 269-285 THERM program, 169-186 thermal analysis, 187-225 thermal bridging, 286-298 thermal performance, 169-186 V vapor barrier, 226-246 vapor pressure, 59-78 vapor retarder, 299-314 vented air layer, 80-93 W wall assemblies, 94-118 wall systems, 187-225 wall-window interface, 31-58 water management, 94-118 wetting and drying potentials, 131147 window, 148-166 window condensation, 31-58 window installation, 31-58 windows, 226-246 wooden residential building, 80-93 www.astm.org Cover Photo courtesy of Keith Nelson, Wiss, Janney, Elstner Associates, Inc ISBN: 978-0-8031-4471-2 Stock #: STP1498