G l a s s T e c h  
Trying to Reason with Hurricane Season”  
Substitutions That Meet Hurricane Codes  
by Sara Neiswanger  
housands of impact-resistant windows, doors  
and skylights have been tested and certified since  
Hurricane Andrew made landfall in 1992. As a  
consequence of the billions of dollars in prop-  
erty damage Andrew inflicted, more stringent  
standards for window systems were adopted. The  
General Rules for Substitution  
General premises for substitution require that  
three out of four initial specimens have passed all  
the appropriate criteria in ASTM E1996 and that  
the original specimens are identical in every way,  
including anchorage and mounting. The general  
premises that apply to any substitution are:  
• Large size qualifies smaller as long as dimen-  
sions do not exceed dimensions of tested width  
or height.  
requirements put into place called for testing of  
window and door systems and changes to any  
component, including framing materials, glazing,  
sealants, weatherstripping, hardware and anchors.  
In order to meet these testing requirements  
while keeping down cost, manufacturers and  
suppliers may consider various glazing and fram-  
ing substitutions. Rules about what component  
changes required retesting and what retesting was  
required were developed by Miami-Dade Product  
Control. (Miami Dade component substitution  
rules are not contained in a single document and  
are therefore not addressed here.)  
ASTM International developed a formalized  
system of component substitution similar to the  
Miami-Dade rules. This is contained in the appen-  
dix associated with ASTM E1996.  
It covers general substitution principles and  
detailed substitution allowances for glazing and  
framing systems. There are three substitution cat-  
• Small missile – all elements that are not infill  
elements shall be allowed automatically.  
• Automatically substituted elements shall be  
allowed to be combined into a system without  
requiring engineering analysis or testing.  
• New components shall be equal to or stronger  
than the components originally tested.  
• Substitution shall not raise the design pressure  
above that at which the three initial specimens  
were qualified.  
• Substitution is not allowed if a failure occurs  
for any reason.  
• No more than three substituted elements can  
be combined before retest.  
• Glazing tapes, sealants, adhesives and back bed-  
ding substitution requires a single test.  
• Glazed products must be impacted twice per  
Sara Neiswanger  
1. Automatic – requiring no additional testing;  
. Engineering Analysis – requiring demonstrat-  
ed or documented performance through a  
review of materials that predicates a minimum  
of equivalent performance; and  
Glass Infil Panels Rules:  
• Color change is automatic.  
• Substitution of a glass coating is automatic once  
it is determined that the product is durable and  
compatible with all the components of the system.  
• Individual glass ply thickness increase shall  
require the testing of one additional specimen.  
A substitution with a decrease in glass ply  
thickness shall not be allowed.  
• A glass type change from annealed to  
heat-strengthened or chemically-strengthened  
requires the testing of one additional specimen.  
• Glass type change from heat-strengthened to  
annealed or heat-strengthened to chemical-  
ly-strengthened shall not be allowed.  
. Single Specimen – requiring one specimen,  
identical to the original specimen qualified with  
the only difference being the element to be sub-  
stituted (i.e. interlayer type for laminated glass).  
Full qualification is defined as a minimum of  
three new specimens being qualified with no credit  
given for any past test specimens. Full qualification  
is not considered part of the substitution parame-  
ters as it is required when the desired substitutions  
are too extensive for a single product and have  
multiple variables that cannot be tested in a single  
test. Full qualification is a new test program that  
allows unlimited changes to any product as it is not Glass type change “to” or “from” fully tem-  
limited by previous design parameters. pered shall not be allowed.  
Architects’ Guide to Glass & Metal  

Architects' Guide to Glass & Metal
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