323 75TH ST SE BLDG A 2023-07-31

Tested panels per the AC273 acceptance criteria are deemed to comply with the IBC load requirements. 2. There were no substantial changes to the load testing requirements of picket style guardrail systems between the 2014 version of AC273 compared to the 2017 versions. As such,the testing completed in 2006 is still valid and can be used to meet the 2015 IBC requirements (Intertek report#3099244C0Q-005A dated December 11, 2006). 3. The 2014 prior version of AC273 added test requirements for glass panels to meet the factor of safety of 4 required per Chapter 2407.1.1 of the 2012 IBC. It was noted that the load testing completed in 2008 on the glass panel system did perform this test. As such,this report is also still valid and can be used to meet the 2015 IBC requirements-up to the limits of the tested panels. (Intertek report #3147626C0Q-003 dated October 20th, 2008 The 2015 and 2018 IBC codes require glass infill panels to be laminated glass. Section 2407 of the IBC requires guards to have laminated and tempered glass with a minimum nominal thickness of 1/4". There are a few exceptions, but laminated glass is the new norm. Glass panel style guardrails, when installed outdoors, also are subject to wind loading. As such,they also need to be designed for the load cases containing wind. The 6 mm tempered glass panels with a panel size of 66.375"x 37.75" were tested to AC273 with a 200 pound force over 1 sq. ft centered in the glass. This factored force is equivalent to a uniform nominal wind force of 25 psf over the area of the glass and therefore should be the upper limit for wind loading on the guardrail system based on the previous testing. 6 mm tempered glass panels supported on two sides with the free unsupported length of 37.75"has a capacity greater than the 25 psf allowable load per ASTM E 1300 -09a. As such, the glass panel guardrail assembly is recommended to only be used only in areas that have a nominal wind force pressure of 25 psf or less without further review. There are many design factors used in determining nominal wind pressures on the balcony railing. Wind Speed, Exposure Category, and elevation above grade are three key items. A chart has been created for the common wind speeds, exposure categories, and various elevations off of grade found in Oregon and Washington to show the limitations of the 6 mm glass panel guardrail system as previously tested. Consulting Structural Engineers Page 2 of 12 610 S.W.Alder Street,Suite 918, Portland,Oregon 97205 Tel (503)226-1286 Fax (503)226-3130