Third Party Verification Claim

Mr. John Ruprecht – Clear View Glass Railings
AET Project No. 05-20608
February 1, 2021
Page 2 of 3
Wind Loading vs. Panel Capacity
The FBC follows the International Building Code (IBC) requirements for wind loads, with ultimate
(factored) wind speeds up to 180 mph; Table 1609.3.1 converts this to 139 psf for unfactored loading,
which was used in the analysis. See Attachment 1 for nominal ground wind speed reference maps from
the Florida Building Code.
The American Society of Civil Engineers (ASCE) Standard 7-10, Chapter 29, provides the analysis
method to convert wind speed (in mph) to pressure (psf) against the glass panel. Using Exposure
Category C (open terrain) and a height of 100 feet above ground; a 139 mph wind produces a calculated
pressure of 81psf. See Attachment 2. The three distinct support points, “spigots”, for these panels
creates stress concentrations around the supports that are best modeled using a finite element model
(FEM). A FEM model was created for this panel using Risa-3D software (version 10.0.1), that modeled
a 60” wide x 39” tall x 13mm thick tempered and laminated panel, with a 81psf surface load applied.
The model generated a 15,979 psi principal axis stress (s) in the panel. See Attachment 3.
The glass used in the panels was tested to determine its structural capacity, using a static load applied to
a test specimen. The specimen was loaded to failure, and the loading was applied to the FEM to
determine the equivalent stresses. The failure stress was 35,767 psi. This modeling shows that the
panels have calculated factor-of-safety of 2.24. See Attachment 4.
Impact Resistance
For building envelope glazing in wind-borne debris regions, glass that is part of a building envelope
must be tested for impact resistance in accordance with American Society for Testing and Materials
(ASTM) E1996. This requirement protects a closed building envelope from being penetrated and
prevents high wind pressures from filling the building, potentially blowing out windows and lifting the
roof off the building. Because these panels are not part of the building enclosure, damage from wind-
borne debris would not penetrate the enclosure and its structural elements. Therefore, this test is not
required for the panels used as a guardrail system.
Summary
In summary, based on our understanding of the FBC requirements, our conclusions are as follows:
1. Each panel is constructed of fully tempered, laminated glass.
2. Each panel is secured to the structure with three supports.
3. A top rail is not required for these panels.
4. Wind pressure – previous testing confirms that the panels meet the 180 mph factored wind
speed requirement, with a calculated factor-of-safety of 2.24.
5. The panels do not require wind debris projectile testing.