James Gooder, Business Unit Manager at SFS Fall Protection Systems, explains why today’s horizontal safety line systems provide assured roof safety without compromising building performance and aesthetic goals
Building design, specification and construction management takes into account numerous legally binding regulations to ensure workers are as safe as possible during the construction stage, and that users and maintenance workers are protected when the building is handed over and in-use. The latter means careful consideration of how different systems and materials will deliver protection on a passive basis – as with fire-resistant glazing – or reactively to perform when called into action, as with roof safety systems.
The long history of working to Building Regulations means that it has become second nature to design-in safety or face the consequences should the worst happen. And that will inevitably involve seeking out solutions that accommodate other design objectives, be they aesthetic, budgetary or performance related.
This is the case when designing-in safety for those people who are tasked with maintaining the building envelope – individuals whose essential work includes working at height, such as on roofs for gutter cleaning, access to air conditioning units, plant and machinery, or to maintain solar or photovoltaic panels, and green roofs.
Horizontal safety line systems have proved themselves in the market here thanks to their flexibility of installation. That can also be for restraint or arrest applications. They are a far cry from the early versions of the 1970s and 80s, taking a fairly primitive concept to deliver a highly reliable life-saving solution. This has been driven by expert engineering insight and product innovation to ensure that horizontal safety line systems are effective without impacting on the roof’s integrity, weather performance or visual appeal. SFS has been at the forefront of this development via its Fall Protection product line, which was originally part of SFS’s specialist building envelope product distribution and consultancy arm, QBM.
As a safety systems manufacturer with its long heritage in building envelope fastening systems, SFS has been able to apply its in-depth knowledge of roofing from across the global group to accurately predict and prove how the safety system fitted to it will perform. Close working relationships with major OEMs (original equipment manufacturers) and a continuous R&D programme here in the UK ensure that effective protection is maintained as new solutions come to market.
The evolution of horizontal safety line systems
Horizontal safety line systems have moved on from the early “through fixed” rigid posts that had to be fastened back to structural steel through the roof build-up. These solid posts would intrude heavily into the roof make-up of the building, and often led to weathering issues. System end loads would be significantly high and shock absorbing elements could only be added “in-line”, and their appearance was often ugly.
Fast forward to 2018 and today’s engineered solutions are fundamentally different. Firstly, there is now no need for posts to be fixed through the roof. The latest generation of horizontal safety line systems allow for the posts to be fixed to the roof skin, whether it be a standing seam, a flat roof construction or corrugated sandwich panels.
The SFS horizontal lifeline post element features built-in shock absorbing technology, which reduces deployment loads to the structure to under 6kN. Its internal features help to minimise the forces that rivets/fasteners would be subjected to in the event of a fall, spreading and dissipating the impact of multi- and single-user falls and preventing damage to the roof structure. And, given the robustness of the technology, a reduced number of fixing points are needed, thus reducing the number of fasteners and speeding up installation.
In the extreme event of a fall, the system will deploy a uniquely patented energy-absorbing element that limits the forces developed during free-fall to no greater than 6kN on the roof structure and even lower on the user attachment point. This allows users uninterrupted or controlled access to many different roofing applications. It can also be installed as a single point anchor for centralised maintenance tasks within a specific area of interest.
As major roofing manufacturers develop profiles of lighter weight and insulation of greater thickness, SFS’s horizontal lifeline system has been designed to complement these advances without compromising structural integrity or user safety. The fully stainless solution is housed in a pre-loaded enclosure that is designed to withstand the stresses exerted by snow and ice build-up, and resist corrosion.
As with all market-leading solutions from SFS, the horizontal lifeline systems have been fully tested for compliance. Initial development was undertaken by SFS at its own state-of-the-art, UKAS-audited testing facilities. These include a 6m x 6m test bed and 12m drop tower, suitable for testing to all current EU regulations and standards. The next stage was for SFS Fall Protection Systems to be independently tested and certified by SATRA for compliance with EN795:2012, as well as CEN/TS16415:2013 multi-user technical specification. SFS also tests to ACR[M]002:2009-(Part2) Testing of Roof Anchors on Roof Systems, known as the Magenta test method.
Any horizontal safety line system must retain its integrity over time and corrosion is one of the biggest threats. In addition to the potential for this to cause failure of the system when it is needed most, the corrosion of safety line components can also cause unsightly rust stains to appear on the roof sheets.
It is a common belief that the various protective surface coatings available offer sufficient resistance to corrosion, but this is not the case. Protective coatings applied to carbon steel elements will only offer temporary corrosion protection.
With a century of component manufacturing expertise to draw upon, SFS has a deep understanding of the problems associated with metals on exposure to the elements. Safety lines are exposed to the weather 365 days a year, 24/7 for life, and any corrosion is measured in terms of loss of performance that would be catastrophic in a safety line.
That’s why EN 795:2012 requires all components to be subjected to a neutral salt spray test in accordance with EN ISO 9227 for a period in excess of 48 hours. Protection and assurance comes with the type of stainless steel used for all components within the SFS system, including internal absorbing elements of the post. A combination of both 304 and 316 stainless steel is used, giving peace of mind to the end user or building owner that any installed system will have a lifespan equal to or beyond the building life.
Please note: this is a commercial profile
Business Unit Manager
SFS Group Fastening Technology Ltd.
Tel: +44 1924 472251