BS 13700 – Permanent Counterweighted Guardrail Systems – Specification
Introduction
Over the last forty years numerous cantilever edge protection systems have been launched in the UK and across the globe.
These products were initially developed to provide temporary edge protection for those carrying out flat roof refurbishments/repairs and featured a lifting base foot and interchangeable cantilever weight, thus allowing work at the edge to continue unhindered while the guardrail remains in position. The early products were featured in HS-G33 published in 1987 (see below)
and tested for conformance to the Health & Safety Executive – Technology Division – Specialist Inspectors Report – Design Loadings for Temporary Roof & Floor Edge Protection (HSE/SIR 15 – 1988), which is now withdrawn.
The free-standing features of these temporary edge protection systems offer key advantages over traditionally fixed guardrails principally because they eliminate the requirement to drill/weather into the floor/roof slab which would otherwise increase the likelihood of water ingress.
This significant advantage led to many manufacturers launching cantilever edge protection systems and demand significantly increased with the introduction of the Workplace (Health Safety and Welfare) Regulations 1992 requiring “ACOP 108 “Secure fencing should be provided wherever possible at any place where a person might fall 2 metres or more.”
British and European Standards
During the mid-90s edge protection systems complied with the following: –
Permanent Systems – BS 6180: 1982 Protective Barriers in and about Buildings
Temporary Systems – HSE Specialist Inspectors Report – Design Loadings for Temporary Roof & Floor Edge Protection (HSE/SIR 15 – 1988) – Superseded by EN 13374 2004 Temporary edge protection systems. Product specification, test methods.
Based on the above, an important question remained unanswered. Which Standard applies to permanent counter balanced edge protection that is not physically connected to the building?
The truth of the matter is neither Standard is truly appropriate. EN 13374 is a Standard for temporary edge protection and does not specify the correct height criteria of 1100mm for permanent products. Equally the wind loading of 600 N/m2 may, in certain situations be inappropriate for sites generally to the North of London and on high rise construction in general. However, the suggested serviceability and ultimate limit state loadings are appropriate for the intended protection of a few persons carrying out maintenance tasks as opposed to BS 6180 which specifies much higher loadings that are beyond the necessary requirements for the intended protection of a few persons carrying out maintenance tasks. (Please see Technical Paper – OVERVIEW OF LEGAL REQUIREMENTS FOR PERMANENT AND TEMPORARY EDGE PROTECTION – for full comparison)
Hence the requirement for a new, appropriate Standard to remove the current ambiguity, BS 13700 – Counterweighted guardrail systems. The specification will be published in Spring 2021 and finally provide a specific standard for permanent counter balanced guardrails.
The key features of BS 13700 include:
• Serviceability and ultimate limit state loadings are the same as EN 13374 Temporary edge protection systems – Product specification, test methods
• This new Standard will be introduced to provide comprehensive guidance for those manufacturing counter balanced guardrail systems that are permanently installed.
a) Testing at 5 degree pitch
b) No provision for upstand/parapet during testing
c) Testing in both dry and wet conditions
d) Horizontal perpendicular loads applied to:-
a. Principal guardrail
b. Intermediate guardrail
c. Intermediate support
d. Toe-board (where option is required)
e) Horizontal parallel loads applied to:-
a. Principal guardrail
b. Intermediate guardrail
c. Toe-board (where option is required)
f) Vertical (up & down) loads applied to:-
a. Principal guardrail
b. Intermediate guardrail
c. Intermediate support
d. Toe-board (where option is required)
g) Working Wind & Combined load
• Every proposed installation will require a site specific wind speed calculation conforming to wind loading criteria in accordance with BS EN 1991‑1‑4:2005+A1:2010.
• Every final installation will have to conform to wind loading criteria in accordance with BS EN 1991‑1‑4:2005+A1:2010.
• This standard requires all guardrail installations to be designed for specific wind speed calculation in relation to the location, height of building and exposure level. All manufacturers will have to provide calculations or software programs to comply with this requirement.
• The standard has also introduced the requirement for annual recertification of counter balanced guardrails installed permanently and provides an examination scheme including the requirement for a wind speed calculation.
System Technical File
Following the “best practice” requirements of BS 7883 :2019 every installation should have a “System Technical File”. This evidence-based document is produced by the System Designer for forward transmission to the Duty Holder and should be placed, where appropriate, in the health & safety file required under the Construction (Design & Management) Regulations 2015.
The Duty Holder must then retain the file and ensure it is available to anyone who may need it for as long as it is relevant – normally the lifetime of the building – to enable them to comply with health and safety requirements during any subsequent work/inspection.
The System Technical File shall include the system design and layout, design calculations, and wind speed calculations permitting compatibility, safety, and operational suitability to be assessed and verified.
Examination Scheme
BS 13700 introduces the requirement for annual recertification of counter balanced guardrails installed permanently and provides an examination scheme including the requirement for a wind speed calculation. Duty Holders must receive a full inspection visit report, including a summary of their building’s edge protection equipment condition.
Conclusion
The introduction of this new Standard – BS 13700:2021 provides a standard for permanent counter balanced edge protection. This brings clarity and consistency for the manufacturer, designer, Duty Holder and Recertification Technician, ensuring these safety critical edge protection systems are designed, installed, inspected, and maintained to the highest standard.
A certificate is no longer sufficient to prove that all is compliant and safe. Specific details of all inspection criteria must be supplied to the Duty Holder, for them to justify to themselves that all is safe.
It is no longer reasonable to assume “it must have been designed and installed correctly in the first place” and there must be evidence of how any edge protection system has been wind speed calculated for the given location of installation. If this information is not available, BS 13700 requires this to be completed during the thorough annual examination of the system.
The introduction of requirements for wind speed calculations and an annual inspection is designed to ensure all crucial elements of a counter balanced edge protection system installation are properly recorded and remain available to facilitate the safe operation and maintenance of the edge protection system.
Graham Willmott
BS 13700 Convenor & UK BSI Principal Expert BS EN 13374
April 2021