ASTM 1996-17 Regarding Insulated Glass Spacers.
This 2017 standard added section A1.9.2 stating tested air spacers making up the insulated laminated unit can be substituted with other spacers.
“A1.9.2 If the conditions in A220.127.116.11 are met, a change in spacer type, shape, or dimension is allowed automatically.”
Section A1.8 states: “A18.104.22.168 Substitutions for insulating glass shall only be made for systems with the impact resistant glazing structurally adhered to the frame or sash glazing leg or bed in the same manner and position as originally tested and approved.”
Section A1.8 states: “A22.214.171.124 Glazing systems typically have a stationary glazing stop that is a permanent part of the frame or sash, or a removable glazing stop (also referred to as a glazing bead), or both. If a removable stop is used, a system can be tested with this stop removed, if it considered to be non-structural and unnecessary to pass the required test.”
***Structurally adhered or structurally glazed is a term used when no glass stops or glazing beads aided in the test. The only way to test is with stops off where the only element holding that glass in place is the sealant. ***
Note: This is assumed no additional testing is performed. ASTM provisions permit one additional sample can be tested to substitute spacers or glass. Contact Engineering Express to further discuss how we can develop a test protocol for your glazing system or provide a review & approval of glass or spacing substitution.
Last Update: March 17, 2021