Third Party Verification Claim

550 Cleveland Avenue North | Saint Paul, MN 55114
Phone [phone] | [phone] | Fax [phone] | www.amengtest.com | AA/EEO
November 13, 2020
Mr. John Ruprecht
Clear View Glass Railings
737 Quentin Avenue South
Lakeville, MN 55043
Re: Code Requirements & Static Test of Clear View Glass Railings “Hercules Glass” guardrail panel
AET Project #: 05-20608
Dear Mr. Ruprecht,
This letter reports building code requirements for guardrails; it also reports test methods and results for
static tests performed on Clear View’s Hercules Glass panel.
The International Building Code (IBC) and International Residential Code (IRC) are “model codes”
created by the International Code Council, intended to be used by states and municipalities as they publish
their own building codes. Section 1607.8 of the IBC requires that “handrails and guards shall be designed
to resist a linear load of 50 plf.” It also requires the system to resist a 200# concentrated load that produces
the “maximum load effect” on any element within the system. The 2018 IRC Table R201.5 extends this
requirement into residential construction. It is understood within the building design industry that laterial
loads applied to the top of the panel create the maximum load effect; structural design assumes this
loading condition.
Section 1607.8 of the IBC also refers to IBC section 2407 Glass in Handrails and Guards that adds a
requirement for all-glass handrails and guards to “be laminated glass constructed of fully tempered or
heat-strengthened glass”; this requirement was added in the 2015 IBC code cycle. Section 2407.1.1
adds the significant requirement: “a design factor of four shall be used for safety”. This addition bumps
up the linear load to 200 plf and the concentrated load to 800#..
Exterior glass guardrail panels are designed to resist two load types: wind loads, and “live” loads such
as a person or object pushing on or striking the panel from the side or from above. Wind loading on a
panel can vary greatly based on location, terrain (wooded vs open) and elevation above ground; these
are governed by publication ASCE 7 (American Society of Civil Engineers) Minimum Design Loads
for Buildings and Other Structures. Wind speeds of 115 psf are used to calculate wind pressures against
the glass, which generally vary from 17 psf (2
nd
story in wooded area) to 35 psf (30 stories tall in open
terrain). The wind speeds required to match the stresses created by the 800# point load are 192 mph for
the 42” tall panel and 215 mph for the 36” tall panel; these are only seen in a Category 5 hurricane or a
tornado. Therefore, the 800# horizontal point load requirement is the worst-case scenario for the panels.
Calculation methods to arrive at these values include computer modeling using finite element analysis,
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