Water penetration through the building envelope is a serious concern. Issues range from what constitutes reasonable performance during extreme conditions, such as hurricanes, to resolving liability for interior water damage and moisture-induced mold. Fenestration is a prime candidate for being perceived as the weakest link in the weather-resistive barrier and, thus, typically receives the greatest scrutiny.
Faulty fenestration is not likely to be the cause of such leakage, especially when the design is certified to the code mandated AAMA/WDMA/CSA 101/I.S.2/A440, “North American Fenestration Standard/Specification for Windows, Doors, and Skylights (NAFS)”, which includes stringent water-penetration-resistance laboratory testing. This testing of factory-made window and door products does not account for leakage caused by improper flashing or poor installation practices—more likely culprits when leaks occur. In addition, water penetration at or near a fenestration product opening may actually originate from the surrounding construction.
How can you tell for sure before problems arise post-occupancy? When properly applied, field testing can be a powerful quality-control mechanism to verify the actual installed performance of fenestration products during construction and retrofitting and prior to occupancy of a building. The key is to apply the appropriate test method to the specific installation.
Performing tests as soon as practical after installation of the fenestration product is crucial in determining if manufacturing, installation and/or perimeter-sealing problems are present before a substantial portion of the project is completed. This ensures issues are found at a time when responsibility for the problems can be assigned and remedial action can be relatively simple and inexpensive. Optimally, testing is performed prior to the installation of drywall, interior finishes and wall/roof materials to provide visual access to hidden parts of the fenestration product and the perimeter joint. In some retrofit applications, this is not possible. In these cases, small portions of interior finishes can be removed to provide visual access. The testing agency may also employ specialized equipment, such as borescopes or thermal-imaging equipment, to minimize disturbance to the interior finish materials.
Industry Consensus Test Methods
To properly test installed fenestration, the Schaumburg, Ill.-based American Architectural Manufacturers Association (AAMA) has developed three field-testing methods:
- AAMA 501.2-15, “Quality Assurance and Diagnostic Water Leakage Field Check of Installed Storefronts, Curtain Walls, and Sloped Glazing System”, is a simple, economical water-spray quality assurance and diagnostic method for finding leaks in fully installed, permanently closed (non-operable) glazing. It includes gaskets, sealant, perimeter caulking, splices and frame intersections. It is not appropriate for testing operable windows and doors and does not simulate the effects of wind-driven rain.
- AAMA 502-12, “Voluntary Specification for Field Testing of Newly Installed Fenestration Products”, is the proper test method for verifying field air leakage and water-penetration resistance of newly installed operable windows and doors and is used for new and existing buildings. Based on ASTM E783, “Standard Test Method for Field Measurement of Air Leakage Through Installed Exterior Windows and Doors”, and ASTM E1105, “Test Method for Field Determination of Water Penetration of Installed Exterior Windows, Curtain Walls and Doors by Uniform or Cyclic Static Air Pressure Difference”, AAMA 502-12 requires the use of a sealed test chamber, typically applied to the interior side of the window or door. The entire installed fenestration product is tested, including the frame; corners; panning; subframe/receptor system; and the adjacent substrate, including the perimeter seals.
- AAMA 503-14, “Voluntary Specification for Field Testing of Newly Installed Storefronts, Curtain Walls and Sloped Glazing Systems”, is similar to AAMA 502 but applicable to storefronts, curtainwalls and sloped glazing systems installed into new and existing buildings. Like AAMA 502, AAMA 503 bases its testing protocols on ASTM E1105 and E783. Also, both AAMA 502 and 503 require the testing be performed during construction and retrofitting and prior to occupancy of a building but in no case later than six months after installation.
But who is going to perform such tests in an objective and professional manner?
Photos: Melissa Baldwin