Use and Misuse of Field Testing
By Dean Lewis
When applied properly, field testing is a useful way to verify the actual installed performance of fenestration products during construction and prior to occupancy of a building. But, in the hands of the misinformed or those with ulterior motives, it can be misused to falsely substantiate claims of alleged product mal-performance. For example, such abuse has been attempted in liability cases involving supposed window leaks and all the ills (real or imagined) that can stem from them.
Whether it’s during a service call or in the courtroom, window manufacturers should be ready with the facts when their products are tested to the wrong specification, tested incorrectly or by inexperienced personnel, or held to inappropriate or unreasonable expectations of installed performance (compared to laboratory test data).
Know the Test Methods
The proper use of field testing under different circumstances is spelled out in ASTM and AAMA test methods and specifications. The latter include: AAMA 501.2-03, Quality Assurance and Diagnostic Water Leakage Field Check of Installed Storefronts, Curtain Walls, and Sloped Glazing Systems; AAMA 502-02, Voluntary Specification for Field Testing of Windows and Sliding Glass Doors; and AAMA 503-03, Voluntary Specification for Field Testing of Storefronts, Curtain Walls and Sloped Glazing Systems. Two of these (AAMA 501.2-03 and AAMA 503-03) do not apply to operable windows and clearly are not intended for residential windows and patio doors. AAMA 501.2 is a simple hose nozzle test used as a quality assurance check during the installation of curtainwalls or storefronts and is not intended to verify performance. It may also be used as a diagnostic tool to determine the source of a leak (roof, wall, window, etc.) when a leak is known to exist.
The recognized field test method for windows and doors is AAMA 502-02. It establishes requirements for verifying air infiltration and water penetration resistance of newly installed products. Testing for structural performance is not included. Based on ASTM E 783 and ASTM E 1105, it describes two test methods (A and B), both of which require the use of a sealed test chamber usually applied to the interior side of the window or door and evacuated to establish a specified pressure differential across the product that simulates wind pressure. Water is then sprayed against the outside surface of the window from a calibrated water spray rack. Performing the tests on the job site as soon as it is practical can be beneficial in determining if manufacturing, installation and/or perimeter sealing problems are present before a substantial portion of the project is completed. In Method A, only the window or patio door product itself is tested. Frame corner seals and perimeter members are excluded, as are any other joints, cracks or openings between the product and the adjacent wall construction. If sealed improperly, these elements can cause uncontrolled water penetration. This limitation to Test Method A should be clearly understood, and can be addressed by using the described optional sill dam test for leakage at lower corners. Method B tests the complete assembly, including the installation, by using a larger test chamber attached to the rough opening members. It thus applies the differential pressure to the joint between the product and the rough opening and tests the efficacy of sealing applied to that opening during installation. This ensures that the entire fenestration product is tested, including the frame, corners, panning, subframe/receptor system, etc. and the adjacent substrate including the perimeter seals. A limitation of Method B is that it may not be possible to differentiate between leaks through the window and leaks through the perimeter sealants.
Manufacturers should especially take note of the following:
• AAMA 502-02 was never intended for testing old window installations;
• AAMA 501.2-03 is not a valid substitute for AAMA 502-02. Reports indicate that the former’s “hose nozzle” test has been loosely applied by unscrupulous advocates in window leakage and mold litigation cases; and
• AAMA 502-02 requires that all testing must be performed by AAMA-accredited testing laboratory, i.e., one recognized as meeting all of the requirements of AAMA 204-98, Guidelines for AAMA Accreditation of Independent Laboratories Per-forming On-Site Testing of Fenestration Products. This assures the specifier that the laboratory has the staff, training, experience and calibrated instruments and equipment to properly perform field testing. AAMA does not accredit labs for field-testing-only. Anecdotes exist in which “shade tree” window testers, armed with little more than a garden hose and an incentive to develop product liability claims, have attempted (in vain, I should note) to obtain AAMA accreditation.
Manufacturers are well advised to be aware of the type of testing and scrutiny their products may encounter after they are installed, and the proper use of the test methods involved.
Dean Lewis serves as manager, product certification for the American Architectural Manufacturers Association in Schaumburg, Ill.
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