Appeal 33748

Section 13.4 of ASCE 7-16

NONSTRUCTURAL COMPONENT ANCHORAGE
Nonstructural components and their supports shall be attached (or anchored) to the structure in accordance with the requirements of this section, and the attachment shall satisfy the requirements for the parent material as set forth elsewhere in this standard. Except where permitted in Section 13.6.12, component attachments shall be bolted, welded, or otherwise positively fastened without consideration of frictional resistance produced by the effects of gravity. A continuous load path of sufficient strength and stiffness between the component and the supporting structure shall be provided. Local elements of the structure, including connections, shall be designed and constructed for the component forces where they control the design of the elements or their connections. The component forces shall be those determined in Section 13.3.1. The design documents shall include sufficient information relating to the attachments to verify compliance with the requirements of this section.

Work proposed for East Precinct Police Bureau is primarily for replacing the roof assembly on the existing building - but the City of Portland (owner) also wanted to improve maintenance staff safety on the roof with the addition of OSHA compliant railings - both mechanically fastened where cost effective and ballasted railings at very limited locations.
The proposed counterweighted (ballasted) railings provide added protection to personnel for maintaining rooftop equipment, clearing debris and accessing the flag pole within 10’ of the edge of the roof. The roof is accessed by maintenance staff only. Linear feet of ballasted = approx. 236 lf vs. mechanically fastened = approx. 347 lf.

The existing CMU and brick veneer walls were designed with a mix of low to medium height parapet walls at the flat roofs. The ballasted railings are proposed to provide OSHA-required fall protection at 42” high at existing parapet wall locations only where the wall is less than 20”. Mechanically-attached OSHA railings are proposed where existing parapet walls are 20” tall, as noted on plan. Equivalent protection is provided by the ballasted railing system that is tested to meet the requirements for personal safety per OSSC 1607.9.1 per attached report. The counterweighted railing system is to be publicly bid with the complete scope therefore the product test results are provided for reference and will be procured with this manufacturer or an approved equal.

The existing CMU and brick veneer exterior walls would require complicated structural upgrades in order to provide 42” tall parapet walls or to mechanically-attach OSHA railings in all locations. We have limited the ballasted railings to only the areas that would require more complicated modifications to the existing building.
Personnel accessing the roof are restricted to maintenance staff with OSHA safety training. At the front facade the existing marquee and flag pole construction would require complete re-design to accommodate new mechanically attached OSHA railings and would alter the building elevation.