Volume 48, Issue 7- July 2013

Codes&Regulations

National Building Code of Canada Says Yes to ASTM E1300
A The Insulating Glass Manufacturers Alliance’s (IGMA) request to see ASTM E 1300 referenced in the Canadian Building Code has been successful. The Part 9 Committee for Houses and Small Buildings of the National Building Code of Canada approved the request, and the reference will be included in the next edition of the code.

“IGMA submitted a code request in September 2007 to both the Part 4 (Structural Design) and Part 9 (Houses and Small Buildings) Standing Committees to include a reference to ASTM E 1300,” says IGMA executive director Margaret Webb. “The Canadian General Standards Board (CGSB) 12.20 Standard was initially published in 1989 and has served the industry well. The overall content of the CGSB Standard and the original ASTM Standard, also initially published in 1989, parallel very closely with regard to determining glass strength for buildings.”

She continues, “There are certain conditions in each standard that are slightly different for the determination of the load resistance of glass to be used in building design. The strength charts for ASTM and the original charts for the CGSB Standard were published to accommodate four-side supported glass under uniform lateral pressures. This was the methodology used in 1989 in both standards. The ASTM standard has been updated continuously since 1989 with the addition of additional glass load resistance thickness selection charts for various support conditions and glass constructions. The CGSB 12.20 standard has not been updated since its original publication date in 1989.” Webb says the committee developed a task group to look at the two standards and make a recommendation on how to address IGMA’s code change request. “This was a relatively large task so it wasn’t possible to address this in time for the 2010 Canadian code cycle,” she says.

The change is expected to provide “much needed flexibility and the tools to ensure appropriate glass design for current products,” according to Webb.

“The most recent versions of the E 1300 Standard have incorporated the load duration for the charts in the standard to be at three seconds for the initial uniform load,” says Webb. “There were factors applied for certain glass combinations to accommodate long-term loads such as snow loads for skylights and other slope glazing conditions. The practice has also incorporated specific charts for monolithic glass, laminated glass and glass-supported on one, two, three or four edges and also includes triple-glazed units.” Webb says a public comment period will be held for the proposed change, though it has not yet opened.

ASTM Publishes Revised Specification for Flat Glass Mirror
The ASTM document C1503 – Standard Specification for Silvered Flat Glass Mirror, developed by the ASTM C14.08 committee, has been reapproved. The Glass Association of North America’s (GANA) mirror division has been very involved over the years with the development of ASTM documents.

“GANA’s mirror division was instrumental in first developing ASTM C1503, and we recently reviewed and agreed to re-publish the standard,” says Mandy Marxen, GANA mirror division chair and vice president of marketing for Gardner Glass Products Inc. “It is a defining technical document for silvered flat glass mirror and the Mirror Division encourages everyone to get it into their company’s list of referenced documents.”

According to ASTM, “this specification covers the requirements for silvered flat glass mirrors of rectangular shape supplied as cut sizes, stock sheets or as lehr ends and to which no further processing (such as edgework or other fabrication) has been done. The quality requirements of silvered annealed monolithic clear and tinted flat glass mirrors up to a certain thickness are also discussed. The mirrors are intended to be used indoors for mirror glazing, for components of decorative accessories or for similar uses.”

The standard specification is available as C1503-08(2013) in the Book of Standards, Volume 15.02.

Also within ASTM C14.08, the group is currently working on a new standard about cleaning architectural flat glass. According to the scope, “airborne and waterborne debris accumulates on glass surfaces and creates a need for the glass to be cleaned in order to preserve its integrity. There are various types of glass and glass coatings that must be considered prior to cleaning. In addition, unprotected glass during construction can become covered with various types of construction debris which may affect the cleaning practice. It is anticipated that this standard would be utilized by many interested parties in the construction industry, including manufacturers, architects, builders, window cleaners and government agencies.”



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