OSHA REQUIREMENTS FOR FAÇADE ACCESS SYSTEMS · PDF fileOSHA REQUIREMENTS FOR FAÇADE ACCESS SYSTEMS Michael Murphy ... (DAVITS): 2.5 x rated load ... Provide Contractor Use...

OSHA REQUIREMENTS FOR FAÇADE ACCESS SYSTEMS

Michael Murphy

Project Engineer

BOMA Brown Bag Lunch

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© Thornton Tomasetti Inc. 2017

Susta inab i l i t y

St ructura l Eng ineer ing

Const ruct ion Eng ineer ing

Façade Eng ineer ing

Weid l inger Protect ive Des ign

Weid l inger Appl ied Sc ience

Renewal

Proper ty LossConsul t ing

Forens icsWeid l inger

Transpor tat ion

About Thornton Tomasetti - Our Practices

Agenda

Façade Access Components and Types

Overview of Various Design and Testing Regulations

Testing Procedures

Summary

Image Credit: https://www.constructionspecifier.com/designing-and-testing-facade-access-equipment/print/

Façade Access Components

and Types

Activities include: Window Washing, Construction,

Repairs/Renovation, Inspections

OSHA estimates that 202,066 serious injuries and 345

fatalities occur annually among workers directly affected by

the final standard.

What is Façade Access and Why is it Needed?

Façade Access ComponentsDavits and Tiebacks

DAVIT ASSEMBLY TIEBACK ANCHORAGE

Façade Access ComponentsDavit Systems

Davit Socket/Sleeve

Davit Base

Davit Arm

Façade Access ComponentsDavit Systems

Davit Arm

Socket

Base

Façade Access ComponentsPortable Outriggers (i.e., “Beams and Weights”)

https://www.archtoolbox.com/materials-systems/equipment/windowwashsuspension.html Source: New England Scaffolding

Façade Access ComponentsParapet Clamps

Façade Access ComponentsBuilding Maintenance Units (BMU or “House Rig”)

Roof-mounted

Façade Access ComponentsRoof-Mounted Tiebacks

https://www.archtoolbox.com/materials-systems/equipment/windowwashsuspension.html

Façade Access ComponentsWall-mounted Tiebacks

https://www.archtoolbox.com/materials-systems/equipment/windowwashsuspension.htmlImage credit: Columbia Building Services, Inc.

Façade Access ComponentsRope Descent Systems (i.e., “bosun’s chairs”)

http://www.highwindowcleaning.com/bosun-chair-window-cleaning.php

Seat Board

Façade Access ComponentsIndustrial Rope Access

No Seat

Board

Question: Which components do I need to test?

Façade Access Components

Answer: Building-mounted support elements.

Building-mounted Contractor-supplied

Davit Bases and Sleeves/Sockets Portable Outriggers (i.e., “Beams and

Weights”)

Davit Arms Parapet Clamps

Permanent tie-back points Everything else (ropes, cables,

harnesses, hoists, etc.)

Building Maintenance Units*

*BMUs fall underneath a different OSHA guideline

Overview of Various Design

and Testing Regulations

Façade Access Regulations

Codes and Standards

Voluntary Standards

“Rated Load” versus “Stall Load” for hoists

Fall-arrest/lifeline anchorages – 5,000 pound load requirement

OSHA’s “Final rule” states that building owners must affirm in writing

that building anchorages for rope descent have been tested, certified,

and maintained as capable of supporting 5,000 pounds – i.e., field

testing

OSHA Design Requirements

Incorporate design loads consistent with

OSHA strength requirements

Hoist Load requirements (DAVITS):

2.5 x rated load x 1.6 safety factor, OR

1.0 x stall load x 1.6 safety factor

Fall-arrest load requirements (TIEBACKS):

3,100 pounds per person x 1.6 safety

factor ~ 5,000 pounds

ASCE/SEI and IBC Design Requirements

IWCA and ASME Testing Standard

IWCAInternational Window Cleaning Association - Window Cleaning Safety

Published once in 2001

Withdrawn in 2011

Proposed testing to 50% of minimum required strength

ASMEAmerican Society of Mechanical Engineers - Safety Requirements for Powered Platforms and Traveling Ladders and Gantries for Building Maintenance

In 2010 proposed the 50% restriction, similar to IWCA

Voluntary standard which contradicts legally-required codes

Testing Procedures

Engineering Check “On Paper”

Step 1: Analyze Existing Components

Step 2: On-site testing Example: Load from roof side to replicate moment arm

Step 2: On-site testing Example: Pull Tiebacks Against Each Other

Monitor Deflections, Ensure Components Return to Original Position

Step 3: During Testing

Provide Contractor Use Plan/Davit Certification by Licensed Engineer

Step 4: Post-Testing Summary

Summary

Starting November 20, 2017 per OSHA Final Rule:

Written assurance requirement from Building Owner begins

300-foot height limit for rope descent systems

Test loads:

Many davit systems were designed for 1,000 pound motors, but 1,250

pound (or even 1,500 pound motors) are common in restoration work

Test load requirement for personal fall-arrest or safety-line tiebacks is

5,000 pounds

Test loads must reach 100% of intended load

Summary and Main Takeaways

Questions?Michael Murphy

Project Engineer

[email protected]

www.ThorntonTomasetti.com