Volume 7, Issue 10 - November 2006

AAMA Analysis

Forensic Field Testing Can Pinpoint Sources of Water Leaks
by Larry Livermore

Uncontrolled water leakage through exterior walls is a serious concern. 

It is important to determine the source of such leakage accurately, as improper or inadequate leak investigations result in wall components wrongfully identified as the cause of water penetration. 

“Windows and doors are often wrongfully identified as the primary source of water leakage because water appears at the window or door opening,” says AAMA Forensic Field Testing Task Group chairperson Scott Warner of Architectural Testing Inc. “Many times the actual source of the leakage is not the window or door.”

An accepted method for identifying the source of water penetration in an occupied building has thus become increasingly desirable. A systematic forensic investigation is the logical way to determine the actual root cause of the leak. 

To accomplish this, the AAMA Task Group first considered making modifications to AAMA 502-02, Voluntary Specification for Field Testing of Windows and Sliding Glass Doors, the recognized field test method for verifying air infiltration and water penetration resistance of newly-installed operable doors and windows. It describes two test methods, both of which require the use of a sealed evacuated test chamber. 

AAMA 502-02 was never intended to be used to investigate known wall leaks, but instead was developed for field testing of new door and window installations for quality assurance or compliance with a project specification. Thus, the Task Group decided that AAMA 502 should continue to serve only its original purpose, with the exception of some necessary revisions to bring it up-to-date. The Task Group determined that the goal was to better define the process for performing a proper forensic investigation of an existing building in order to determine the root cause of the water penetration, which may involve only recreating leaks that are known to have occurred. Because such an investigative approach involves testing that is different from that set forth in AAMA 502-02, it reinforced the idea that a separate document needed to be developed. 

“The test pressures used for quality assurance field testing often do not correlate with in-service site environmental conditions,” notes Warner. “It is erroneous to assume that the window or door is the cause of the leakage because it does not satisfy a product certification which is based on a laboratory test environment.”

Hence, work is progressing to finalize a new testing guideline, to be identified as AAMA 511, provisionally entitled Voluntary Guideline for Forensic Water Leakage Testing of Fenestration Products. The new guideline will reference and expand on each step in ASTM E 2128, which describes the procedure for a systematic forensic investigation into the causes of water leakage that exceeds the planned resistance or temporary retention and drainage capacity of an exterior wall. 

AAMA 511 is being designed to provide supplemental guidance in some applications of ASTM E 2128 and highlights required information and actions regarding door and window investigations. The test methods are similar to those referenced in AAMA 502-02 for newly-installed products, but have specific differences in preparation and data interpretation. The guideline will also take into consideration the actual weather conditions of the project site prior to testing. 

In application, the new AAMA 511 guideline will recognize a wall as a system, encompassing its exterior and interior finishes, fenestration, structural components and components for maintaining the building interior environment. It will be able to assist industry professionals in selecting the appropriate testing protocols for field investigations of windows and doors which have been installed six months or more prior to testing. Tentatively scheduled for release next year, the document may be of particular value in cases where water penetration is evident and the source is unknown.

Larry Livermore serves as technical standards manager for the American Architectural Manufacturers Association in Schaumburg, Ill. He may be reached at llivermore@aamanet.org

DWM
© Copyright 2006 Key Communications Inc. All rights reserved.
No reproduction of any type without expressed written permission.