FGIA updates guidelines for insulating glass dimensional tolerances in fenestration products
Posted on May 23rd, 2025
Schaumburg, Illinois – The Fenestration and Glazing Industry Alliance (FGIA) has updated guidance for the dimensional tolerances of insulating glass units (IGUs) produced for installation in fenestration products. IGMA TB-1200-25, Guidelines for Insulating Glass Dimensional Tolerances, is now available for purchase in the FGIA online store. This document was last updated in 2016.
IGMA TM-1200 is intended to assist in achieving successful performance of IGUs, both dual and triple units. These guidelines are for the consideration and use of manufacturers and other interested parties in their own independent business judgment, while considering their particular glazing or installation configuration.
“This technical bulletin provides guidelines for typical glass tolerances in the absence of specific information from the glass manufacturer,” said Scott Corley (ODL), vice chair of the FGIA Dimensional Tolerances Task Group. “This revision removed some redundancies with other documents and cleaned up some tables and units.”
IGMA TB-1200-25, as well as other documents available from FGIA, may be purchased from the online store at the discounted member rate of $18 or the non-member price of $36.
For more information about FGIA and its activities, visit FGIAonline.org.
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