Why Fenestration, Why? Water Testing Problems and Solutions John C. Wylie, REWC, RRO, PE Construction Science and Engineering, Inc. 218 East Main St., Westminster, SC 29693 864-906-2370 • johnwylie@constructionscience.org Wayne Butler, Associate AIA and Edward Polk, RRC, RRO Applied Building Sciences, Inc. 2308 Cosgrove Ave., North Charleston, SC 29405 843-724-1464 • wbutler@appliedbuildingsciences.com IIBEC 2020 Virtual International Conve ntion & Trade Show | June 12-14, 2020 W ylie and Butler | 245 246 | Wylie and Butler IIBEC 2020 Virtual International Conve ntion & Trade Show | June 12-14, 2020 John C. Wylie has over ten years of experience as an engineering consultant and engineering intern, primarily in the areas of deficient construction, structural analysis, and collapse/ damage investigations. Wylie is licensed as a professional engineer in four states and is a Registered Exterior Wall Consultant with IIBEC. He is responsible for the inspection and structural analysis of a wide variety of building enclosure and framing systems, including roof, wall, and guardrail systems. Wylie has provided deposition testimony during a litigation case, and he has presented several technical papers at national and regional conferences. He is a member of IIBEC’s Interface Editorial Board. Wayne Butler’s architectural design practice focuses on building enclosure design, consulting, and diagnostic testing for a variety of architectural projects. The emphasis of his work has been in the hot/humid, high-wind/high-seismic zone of the Southeast. Wayne received both his B.S. and master’s in architecture from Clemson University. Wayne is past chair and current board member of the Building Enclosure Council|Charleston; served on the Building Enclosure and Environmental Council – BETEC Material & Innovation Committee; is an active voting member of ASTM E06, Performance of Buildings; and is a board member and mentor with Architecture, Construction, and Engineering’s (ACE’s) Mentor Program of America (Charleston Affiliate). Nonpresenting Author: Edward Polk, RRC, RRO ABSTRACT SPEAKERS New construction and renovation projects provide their own set of unique challenges, especially during the installation and integration of new fenestration systems (e.g., sliding glass doors and windows). This paper will seek to analyze both similar and distinctive modes of water penetration failure that have been observed during multiple sessions of water testing performed in general accordance with accepted industry standards. This paper will further analyze and discuss the water testing failures related to detail design and constructability issues associated with work performance and project management, using several case studies. Applying the learned knowledge of water penetration failures during the design and installation of fenestration systems of new or renovation projects will lead to improved performance and life expectancy of the building enclosure as a whole. INTRODUCTION Structural engineers and architects typically have two unique and sometimes conflicting views when it comes to the building enclosure, a common example being that structural engineers like to minimize the number of fenestration openings, while architects like to utilize and maximize the number of fenestration openings for a variety of reasons. More than ever, design professionals and building enclosure consultants are pushing the boundaries of integrating exterior cladding and fenestrations, for both new construction and renovation projects. As the construction industry continues to evolve and change, design professionals and consultants endeavor to ensure that buildings are structurally adequate and the building enclosure elements, such as fenestrations, perform to prevent incidental water penetration into the interior of our buildings. New construction and renovation projects present their own unique set of challenges, especially during the installation and integration of new fenestration systems. As wall assembly performance continues to increase across the nation, one of the most prolific wall components, fenestration systems, remains integral to achieving the performance requirements. This may be intuitive, but it’s worth stating that fenestration system fabrication and installation provides a narrow margin of error and either can be decoupled from the other, meaning that a manufactured window or door is intended to be installed in an assembly not controlled by lab conditions. Given that intuitive concept, the various performance requirements met by fenestration manufacturers in order to bring their respective product(s) to market are certainly noteworthy. Once fenestration systems are installed, how are performance requirements reconciled and have they changed? What performance expectations do owners have for their installed fenestration products? In-situ water penetration testing assures both installers and owners of adequate performance and functionality in normal service and significant weather events. No matter how simple or complex the project, the authors have observed similar and distinctive modes of water penetration failure to fenestration systems during sessions of water testing performed in general accordance with accepted industry reference standards. The focus of this paper will be to analyze and discuss the water testing failures due to detail design and constructability issues associated with the performance of the work and project management by use of several case studies. Applying the knowledge of past water penetration failures to the current design and installation of fenestration systems during the construction phase will lead to improved performance and life expectancy of the entire building envelope for both new and renovation projects. BUILDING CODES AND INDUSTRY STANDARDS Fundamentally, the intent of the commercial and residential building codes (i.e., building codes) is to provide the design professional, building enclosure consultant, contractor, authority having jurisdiction, etc., with the minimum requirements to which a building can by law be constructed. The building codes include both prescriptive requirements that specifically state how a building should be constructed and performance requirements that provide a minimum level of building performance. Some of the performance and prescriptive requirements within the building codes are founded on the bases of leading industry standards and manufacturer installation instructions. Building Code Requirements As previously mentioned, the building code requirements for newly installed fenestration systems (e.g., windows and sliding glass doors) in both new construction and renovation projects are based on performance and prescriptive requirements. Table 1 provides a summary of the performance and prescriptive requirements for new fenestrations from the 2018 International Building Code (IBC) and the 2018 International Residential Code (IRC). Why Fenestration, Why? Water Testing Problems and Solutions IIBEC 2020 Virtual International Conve ntion & Trade Show | June 12-14, 2020 W ylie and Butler | 247 New construction and renovation projects present their own unique set of challenges, especially during the installation and integration of new fenestration systems. As wall assembly performance continues to increase across the nation, one of the most prolific wall components, fenestration systems, remains integral to achieving the performance requirements. As shown in Table 1, new fenestration systems are required to meet minimum performance requirements in accordance with code-referenced industry standards as described in the American Architectural Manufacturers Association (AAMA), Window and Door Manufacturers Association (WDMA) and Canadian Standards Association (CSA) NAFS – North American Fenestration Standard/Specification for Windows, Doors, and Skylights (AAMA/WDMA/CSA 101/I.S.2/A440)1 and American Society of Civil Engineers (ASCE) Minimum Design Loads for Buildings and Other Structures (ASCE/SEI 7-10).2 Prescriptive requirements outlined by the building codes rely on the fenestration systems being installed in accordance with the manufacturer installation instructions. However, it should be noted that the building codes do not reference in-situ standards related to water penetration testing after the fenestration has been installed as a component of the new construction or renovation project. Industry Standard – AAMA/WDMA/CSA 101/I.S.2/A440 Organizations such as AAMA, WDMA, and CSA are considered to be industry leaders in developing and producing standards pertaining to fenestration systems. The code-referenced standard AAMA/WDMA/CSA 101/I.S.2/A440 is used in the testing and rating of windows, doors, tubular daylighting devices, and unit skylights. Additionally, it is considered to be internationally accepted as the performance standard/specification for windows and doors. AAMA/WDMA/CSA 101/I.S.2/A440 defines performance class requirements based on the minimum performance grades (PG), design pressures (DP), uniform load structural test pressures (STP), and water penetration resistance test pressures. The performance classes are as follows: • R – Commonly used in one- and two-family dwellings. • LC – Commonly used in low-rise and mid-rise multifamily dwellings and other buildings where larger sizes and higher loading requirements are expected. • CW – Commonly used in low-rise and mid-rise buildings where larger sizes, higher loading requirements, limits on deflection, and heavy use 248 | WylieIE and Butler IIBEC 2020 Virtual International ConveVEntion & Trade Show | June 12-14, 2020 Referenced Code Section and Requirement Type of Code Requirement 2018 IBC 1404.13 – Exterior Windows and doors installed in exterior Performance W indows and Doors walls shall conform to the testing and performance requirements of Section 1709.5 2018 IBC 1404.13.1 – Installation Windows and doors shall be installed Prescriptive in accordance with approved manufacturer’s instructions. 2018 IBC 1709.5 – Exterior The design pressure rating of exterior windows and Performance W indow and Door doors in buildings shall be determined in As semblies accordance with Section 1709.5.1 or 1709.5.2. 2018 IBC 1709.5.1 – Exterior Exterior windows and doors shall be tested Performance W indows and Doors and labeled as conforming to AAMA/WDMA/CSA 101/I.S.2/A440. 2018 IRC R609.1 – General Windows and doors shall be installed and flashed Prescriptive in accordance with the fenestration manufacturer’s written instructions. Window and door openings shall be flashed in accordance with Section R703.4. Written installation instructions shall be provided by the fenestration manufacturer for each window or door. 2018 IRC R609.2 – Performance Exterior windows and doors shall be capable of Performance resisting the design wind loads specified in Table R301.2(2) adjusted for height and exposure in accordance with Table R301.2(3) or determined in accordance with ASCE 7 using the allowable stress design load combinations of ASCE 7. 2018 IRC R609.3 – Testing Exterior windows and sliding doors shall be Performance and Labeling tested by an approved independent laboratory, and bear a label identifying manufacturer, performance characteristics and approved inspection agency to indicate compliance with AAMA/WDMA/CSA 101/I.S.2/A440. Table 1 – Summary of the performance and prescriptive requirements for fenestrations from the 2018 International Building Code (IBC) and the 2018 International Residential Code (IRC). are expected. • AW – Commonly used in high-rise and mid-rise buildings to meet increased loading requirements and limits on deflection, and in buildings where frequent and extreme use of the fenestration products is expected. In an effort to provide a primary set of requirements for the fenestration systems, AAMA/WDMA/CSA 101/I.S.2/A440 established gateway performance requirements that provide the minimum allowable performance levels that a gateway test specimen shall achieve in order for that product to be rated with a particular performance class (i.e., R, LC, CW, or AW). Figure 1 provides the minimum allowable performance levels for the gateway requirements. The gateway requirements provide the design professional or building enclosure consultant with the appropriate level of performance based on several factors that include, but are not limited to, environmental conditions, height of fenestration, type of building, and type of fenestration. WATER PENETRATION TESTING STANDARDS As a means to provide assurance or compliance with project specifications not only to owners, but also to design professionals, building enclosure consultants, and contractors, water penetration testing is often performed on the newly installed fenestration systems during new construction and renovation projects. Though the building codes do not offer commentary regarding water penetration testing, organizations such as ASTM International (formerly known as the American Society of Testing and Materials, and now ASTM) and AAMA have developed standards that provide the basis for the means and methods of performing water penetration testing for newly installed fenestration systems. ASTM E1105 ASTM International developed and produced the technical standard ASTM E1105, Standard Test Method for Field Determination of Water Penetration of Installed Exterior Windows, Skylights, Doors, and Curtain Walls, by Uniform or Cyclic Static Air Pressure Difference.3 The scope of this standard includes test methods that determine the resistance of fenestration components (i.e., windows, curtainwalls, skylights, and doors) to water penetration testing when subjected to an air pressure differential across the product (from the exterior to the interior). The air pressure differential across the fenestration system is created by a sealed chamber, installed either from the interior or exterior, that includes an air source which supplies air (i.e., positive pressure) or exhausts air (i.e., negative pressure) at a required calculated rate while simultaneously spraying water onto the exterior surface of the fenestration system. The major components of the water penetration system include the following (Figure 2): • Test Chamber – A chamber or box constructed from suitable materials (e.g., wood, plastic, or similar) that is sealed against the fenestration for purposes of creating the air pressure differential. The chamber shall not come in contact with a part of the fenestration that will restrict water penetration during testing. • Air System – A controllable air system that provides a constant IIBEC 2020 Virtual International ConveVEntion & Trade Show | June 12-14, 2020 W wylIE and Butler | 249 Figure 1 – Gateway requirements in AAMA/WDMA/CSA 101/I.S.2/A440. Figure 2 – ASTM E1105, General Arrangement of Water Penetration Test Apparatus. air flow at a fixed pressure for the required testing method. • Pressure-Measuring Apparatus – A device to measure the test pressure difference across the fenestration within a tolerance of ±2% or ±0.01 in. of water column (±2.5 Pa of water column), whichever is greater. • Water Spray System – A grid of evenly spaced nozzles located at a uniform distance from the exterior surface of the fenestration that delivers water at a minimum of 5.0 U.S. gal/ft2*h (3.4 L/m2*min). Based on this standard, the selected fenestration system shall be subjected to one of the following testing procedures: — Procedure A – A test under a uniform static air pressure differential with a continuous water spray for 15 minutes. — Procedure B – A test under a cyclic static air pressure differential with intervals of five minutes with pressure and one minute without pressure. A continuous water spray is applied during the duration of the test. The test shall be cyclic for a total time of no less than 15 minutes. Although this standard provides the testing procedures and requirements for determining the water penetration resistance of a fenestration system subjected to an air pressure differential, it does not provide specific guidance as to how each product performance class is to be tested. That guidance is gained in the AAMA 502 reference standard. AAMA 502 AAMA developed and produced the technical standard AAMA 502, Voluntary Specification for Field Testing of Newly Installed Fenestration Products.4 The scope of this standard is to establish the requirements for field test specimens, apparatus, sampling, test procedures, and test reports for verifying water penetration resistance performance of newly installed fenestration systems. This specification pertains to fenestration systems installed during construction, but no later than six months after the issuance of the building occupancy permit. It should be noted that the fenestration products defined with AAMA 502 are based on the requirements of AAMA/WDMA/CSA 101/I.S.2/A440. The test methods outlined within this water penetration reference standard are required to be in general accordance with ASTM E1105. Specifically, the test chamber is required to be sealed in a manner that creates a pressure differential across the entire fenestration system, including the subframe/receptor and/or panning, and the perimeter seals. Additionally, no interior finishes are to be installed immediately adjacent to the test area, allowing for observations of potential water intrusion during the testing. Water penetration testing of the subject components should be initiated when a representative number of fenestration systems have been completely installed inclusive of the perimeter sealant joint. There are a multitude of considerations and variables that can inform the testing sample size. The overall size of the project, total number of completed installations, exposure based on façade, height above finished grade, and unit operation, are just a few of the possible variables to consider in selecting the testing sample size. If water intrusion is observed during testing and the source of the leakage cannot be readily determined, a forensic evaluation using the procedures outlined in AAMA 511, Voluntary Guideline for Forensic Water Penetration Testing of Fenestration Products, shall be performed while maintaining the test pressures and the methods defined in AAMA 502. It should be noted that the AAMA 511 forensic evaluation of fenestration systems is considered to be outside the scope of this paper, and as an aside, is often not included in testing protocols. All newly installed fenestration systems, with the exception of product performance class AW, are to be water tested using Procedure B – Cyclic Static Air Pressure Difference as outlined in the above-referenced standard ASTM E1105. Fenestration systems with performance class AW shall be water tested using Procedure A – Uniform Static Air Pressure Difference. The water penetration resistance tests are to be performed at a static test pressure equal to two-thirds of the tested and rated laboratory performance test pressure as indicated by the product designation in AAMA/WDMA/CSA 101/I.S.2/A440, unless other criteria are specifically established by project requirements. The reduction in static test pressure is to account for the difference in laboratory and field conditions that may be within industry-accepted tolerances but are not considered to be perfectly plumb, level, and square within the rough opening. ASTM E2112 ASTM developed and produced the technical standard ASTM E2112, Standard Practice for Installation of Exterior Windows, Doors and Skylights.5 Though this technical standard provides specifications regarding the installation of new and existing fenestration systems, it does provide commentary about field testing fenestration systems as a quality assurance procedure or proof of compliance with project specifications. Specifically, the installer shall be familiar with the procedures and requirements outlined in both the ASTM E1105 and AAMA 502 water testing standards. WATER TESTING PROBLEMS AND SOLUTIONS In an ideal world, there would be no need for water penetration testing, as the installed fenestrations would be properly integrated and perfectly plumb, level, and square within the rough opening. However, in the real world, construction tolerances are not perfect (though they can be close) such that unanticipated problems may cause future issues that can compromise the functionality of the fenestrations and their ability to perform adequately. Whether it is new construction or a renovation project, similar and distinctive modes of failure directly associated with water penetration have been observed by the authors when testing has been performed in general accordance with ASTM E1105 and AAMA 502. The following in-situ examples of water penetration failures were observed from both new and renovation projects and attributed design details and constructability issues associated with the work performance and project management. Issue I – Sub-Sill and Fenestration Frame Fenestration systems installed in hurricane-prone coastal environments are subjected to some of the most extreme conditions, from salt-laden air coupled with elevated relative humidity, to high-wind and rain events. These conditions appear to be compounded as the rough openings of 250 | WylieIE and Butler IIBEC 2020 Virtual International ConveVEntion & Trade Show | June 12-14, 2020 fenestration systems are progressively getting larger, and buildings are consistently being constructed higher. In order to provide a fenestration system with enough support to adequately transfer the wind load, independent structural sub-framing is installed at the head and sill. The fenestration systems are then simply snapped into the sub-framing at the time of installation. During a water testing session, a sliding glass door with an AW product performance class was subjected to Procedure A of AAMA 502. During the 15-minute static-air water penetration resistance test, evidence of water leakage was observed at the intersection of the fenestration-to-sub-sill framing. When two different framing systems are intimately jointed together, it is critical to ensure that the joints are properly sealed to prevent the occurrence of water intrusion. For this particular project, the critical location was at the rear vertical leg of the sub-sill where a bead of sealant was installed into a prefabricated slot to ensure intimate contact with the fenestration framing (Figure 3). During installation, the fenestration framing can move slightly, creating small voids or holes in the sealant. These small voids or pinholes can be exposed during water testing, especially when the interior chamber pressure is significant. After discussions with the manufacturer and contractor, an additional bead of sealant was installed on the exterior surface of the fenestration-to-sub-sill intersection. This mode of failure was not observed during subsequent water penetration resistance testing of the remaining sliding glass doors within the sampling. As the design professional and building enclosure consultant, it is important to identify the critical locations where water intrusion may occur and consider the installation and assembly of the system, especially if it requires a multitude of products. This understanding of the fenestration system proves useful when preventative or corrective action is required. Issue II – Incomplete Exterior Cladding Whether it is new construction or a renovation project, it is important for the weather-resistive barrier (WRB) or exterior cladding and sealant joints installed adjacent to the fenestration systems to be complete. Even though protective coverings can be used to isolate the fenestration and sealant joints, unforeseen gaps in the WRB or between the exterior cladding and joints can allow incidental water to penetrate the interior during water penetration resistance testing. The pressure differential created by the negative (i.e., vacuum) conditions of the interior chamber can draw water in from the exterior. Therefore, prior to any water penetration resistance test, it is important to inspect the exterior for any gaps or separations adjacent to the perimeter of the fenestration system. Miscommunication among the contractor, design professional, and building enclosure consultant prior to water penetration resistance testing can result in a failure before testing begins. As shown in Figure 4, the general contractor stated that the exterior cladding IIBEC 2020 Virtual International ConveVEntion & Trade Show | June 12-14, 2020 W WylieIE and Butler | 251 Figure 4 – Absence of exterior cladding adjacent to the newly installed fenestration. Figure 3 – Critical sealant location at fenestration-to-sub-sill framing intersection. had been installed adjacent to the newly installed fenestration system on a renovation project. However, during pre-test inspection, the exterior cladding immediately adjacent to the test area had not been installed. Undoubtedly, a water test at this location would have resulted in water penetration if a pretest inspection had not been completed. As the design professional and building enclosure consultant, it is important to make sure that the fenestration system and adjacent exterior claddings are properly installed, and the engineered sealant joints have had adequate cure time to allow for a fair and representative water penetration resistance test for purposes of comparison during a project. Issue III – Sub-Sill Sealant As discussed in Issue I – Sub-Sill and Fenestration Frame above, when two different framing systems are intimately jointed together, such as the sub-framing and fenestration framing, it is critical to ensure that the joints are properly sealed to prevent the occurrence of water intrusion. In an effort to prevent water intrusion, many contractors will install supplemental sealant where the sub-framing terminates adjacent to the fenestration framing. For example, sealant will be installed between the sub-sill end dam and jamb mullion of the fenestration frame. In this project, several sliding glass doors with an AW product performance class were subjected to Procedure A of AAMA 502. During the water penetration resistance testing, evidence of water leakage at several of the sliding glass doors was observed at the intersection of the sub-sill end dam and fenestration jamb (Figure 5). Closer examination of these intersections following water testing did not exhibit any open gaps or holes in the sealant. It should be noted that the sub-sill was designed with weep holes to allow incidental water to exit. Following extensive discussions with the manufacturer and contractor, it was concluded that the weep holes located within the sub-sill needed to be closed with a bond breaker and sealant. Though the sub-sill was designed with weep holes, the incidental water drawn into the sub-sill during water testing was not being purged, thereby creating a head of water within the sub-sill and subsequently overtopping the back dam. The installation of the sealant over the weep holes of the sub-sill created a barrier-type system versus the originally designed drainage system. It should be noted that subsequent water penetration testing did not recreate this type of water leakage during the course of the project. This type of change could be considered an undesirable consequence and a potential problematic maintenance issue for the owner. However, by working with the manufacturer on site, design changes could be implemented on future fenestration systems. Issue IV – Glazing Panel Gasket In renovation projects, it is not always feasible to have a one-size-fits-all fenestration system opening due to inconsistencies and variables in the original construction. Therefore, the fenestration framing may need to be field fabricated with custom glazing panels to ensure proper installation. When fenestration systems are fabricated by the manufacturer, there is a series of quality control checks and inspections performed prior to approval for shipment. In the event that fenestration systems are field fabricated, it can be more difficult to perform the same level of quality control and inspections as that of the manufacturer. Due to the variability of rough opening dimensions, one renovation project required that the frames for the new windows be fabricated on site. During a water testing session at one particular window, evidence of water leakage was observed at three locations almost simultaneously, with one water leak at the intersection of the vertical and horizontal mullion and two water leaks at the intersection of the horizontal mullion and jamb framing (Figure 6). When the glazing panels were removed, it was revealed that although sealant was properly installed, water migrated around the gasket due to the pressure differential during water testing. The gasket at the top 252 | WylieIE and Butler IIBEC 2020 Virtual International ConveVEntion & Trade Show | June 12-14, 2020 In renovation projects, it is not always feasible to have a one-size-fits-all fenestration system opening due to inconsistencies and variables in the original construction. Figure 5 – Location of water leakage at the sub-sill end dam and fenestration jamb. of the glazing panels did not properly seal and created a void that allowed water to penetrate the interior. Due to the magnitude and location of the water intrusion during water testing, the window was scheduled to be retested following the removal and replacement of the original gaskets and sealants. At the next water penetration resistance testing session (following proper cure time of the sealants), the window successfully passed the retest. These types of issues are difficult to determine in the absence of water penetration resistance testing, especially where fenestration systems are field fabricated. Issue V – Fenestration Operable Panel Though owners have numerous options regarding the type, color, or configuration of a fenestration, the basic functionality of a glazing unit within a specific fenestration system is designed to be either operable or fixed. Where fenestrations have an operable glazing unit, such as a window sash or slider in a glass door system, the critical location for several types of issues—whether water leakage, air drafts, or insects—is at the intersection of the operable and fixed panels. The likelihood of water leakage during a water penetration resistance test increases if the operable panel is not properly installed or the weatherstripping does not conform to a proper fit. Prior to any water penetration resistance testing, the operable panel of a fenestration is checked to ensure proper movement and closure. Though these basic checks may appear adequate, water leakage can still occur during water testing due to misalignment of the operable panel within the track or improper fit of the weatherstripping. For instance, water leakage was observed during the testing of a sliding glass door at the intersection of the operable and fixed panels (Figure 7). Following the water penetration resistance testing, the sliding glass door was observed to be misaligned within the track and did not provide a proper fit with the fixed panel. Discussions with the contractor determined that the sliding glass door needed to be realigned and adjusted prior to successfully passing the water retest. Thorough inspection of the alignment of the operable panel performed by the contractor can assist in reducing the potential of a failure during a water penetration resistance test. IIBEC 2020 Virtual International ConveVEntion & Trade Show | June 12-14, 2020 W WylieIE and Butler | 253 Figure 6 – Location of water leakage at a window during water testing. Figure 7 – Location of water leakage at the operable-to-fixed panel intersection. Issue VI – Use of Protection The use of protection (e.g., vinyl or plastic sheets) during water penetration resistance testing can be vital—whether the intent is to isolate the newly installed fenestration systems and joints or to protect adjacent sections of a building. However, failures that occur during water testing can contribute to the incomplete coverage of the protection, allowing incidental water to migrate behind the protection and into areas that were unattended. During the renovation project, new AW product performance class windows were installed adjacent to existing hard-coat stucco cladding. Protective plastic sheets were attached adjacent to the engineered sealant joint and window to segregate the existing cladding during water testing. During the water penetration resistance testing, water intrusion was observed to penetrate the interior between the window frame and existing light-gauge metal framing wall. Following the water testing, it was observed that small gaps within the protective plastic allowed incidental water to migrate into a small void in the existing cladding at the bottom of the window (Figure 8). Though this particular water penetration resistance test resulted in a compliant window unit, the evidence of water intrusion inside the wall cavity propagated discussions with the contractor, and it was determined that localized voids in the exterior cladding—especially adjacent to the new fenestration—needed to be included as part of the repair project. Issue VII – Holes in Sealant As previously discussed, AAMA/WDMA/CSA 101/I.S.2/A440 defines performance class requirements for fenestration systems based on the minimum performance grades (PG), design pressures (DP), uniform load, structural test pressures (STP), and water penetration resistance test pressures. The pressure used during water penetration resistance testing is based on two-thirds of 15% of the rated laboratory performance. For example, a fenestration with an 80-lb./ft.2-rated laboratory performance would be tested with a chamber pressure of 8 lb./ft.2 (80 psf x (2/3) x 0.15 = 8.0 psf). Therefore, the test chamber pressure is proportionate to the rated laboratory performance pressure. The pressure differential across a fenestration system can be very significant, depending on the rated laboratory performance. As such, small voids and pinholes in the sealant can be exposed during water penetration resistance testing due to the 254 | WylieIE and Butler IIBEC 2020 Virtual International ConveVEntion & Trade Show | June 12-14, 2020 Figure 8 – Location of water penetration from a void in the exterior cladding. Figure 9 – View of hole in sealant. Figure 10 – View of void in sealant. pressure differential. During moderate storm events, the pressure differential across the fenestration system may not be significant enough to draw water into the interior; however, during an extreme storm event such as a hurricane, the pressure differential can be significant enough to allow water to penetrate the interior. Water penetration resistance testing of fenestrations located within hurricane-prone coastlines have resulted in failures due to small voids or holes in the sealant. An initial inspection of the sealant prior to a water test may leave small voids and holes undetected. The small voids or holes can be caused by the thinning out of the sealant, improper tooling, or adhesion failure. During water testing, the water level was observed increasing along the back dam of the newly installed sliding glass door. Inspection of the sealant following the water testing concluded that a small hole in the exterior sealant joint allowed water to fill and overtop the sill pan due to the pressure differential across the fenestration system (Figure 9). Prior to applying water to the exterior face of the fenestration system, a high-pitched whistling sound was detected during the preparation phase while depressurizing the interior chamber. A smoke pen was used to locate a small void in the sealant at the top of the new sliding glass door (Figure 10). Again, due to the high interior chamber pressure, the pressure differential across the sliding glass door resulted in the high-pitched sound. During the inspection process, it may be difficult to observe and locate small voids and holes in the sealant. These types of issues are difficult to determine in the absence of water penetration resistance testing; however, being mindful of locations where sealant may be difficult to install can alleviate the potential of failure during a water penetration resistance test. CONCLUSIONS New construction and renovation projects present their own unique set of challenges, especially during the installation and integration of new fenestration systems. It is abundantly important that these elements be subjected to water penetration testing to assure owners of adequate performance and functionality. Similar and distinctive modes of water penetration failures directly associated with fenestration systems have been observed during sessions of water testing performed in general accordance with accepted industry standards. The issues presented by several case study projects are considered to be a mixture of detail design and constructability issues. Applying the knowledge of past water penetration failures to the current design and installation of fenestration systems during the construction phase will lead to improved performance and life expectancy of the entire building envelope for both new and renovation projects. REFERENCES 1. American Architectural Manufacturers Association (AAMA), Window & Door Manufacturers Association (WDMA) and Canadian Standards Association (CSA). “NAFS – North American Fenestration Standard / Specification for Windows, Doors, and Skylights.” (AAMA/WDMA/CSA 101/I.S.2/ A440). 2. American Society of Civil Engineers (ASCE). “Minimum Design Loads for Buildings and Other Structures.” (ASCE/SEI 7-10). 3. ASTM International, ASTM E1105 – 15. “Standard Test Method for Field Determination of Water Penetration of Installed Exterior Windows, Skylights, Doors, and Curtain Walls, by Uniform or Cyclic Static Air Pressure Difference.” Approved August 1, 2015. 4. AAMA 502 Voluntary Specification for Field Testing of Newly Installed Fenestration Products 5. ASTM E2112 Standard Practice for Installation of Exterior Windows, Doors and Skylights IIBEC 2020 Virtual International Conve ntion & Trade Show | June 12-14, 2020 W ylie and Butler | 255
