Brothers in arms - SFS's roof is safe

When UK fastener manufacturer fastener manufacturers SFS intec needed access their roof for some routine gutter maintenance, they were in for a surprise - their roof mounted horizontal safety line system was classed as unsafe for use.  Sister SFS company QBM, who are fast becoming a leader in this field, conducted a site survey and made some recommendations on how to make everything safe again.

The original system was 18 years old, fixed with rigid fabricated anchors, through to the main steel structure.  The original seals / flashings had become stretched due to the continual movement of composite roof panels and were now a potential for roof leaks. The system had not been recertified as laid down by in BS EN 365: 2004 and BS 8437 "periodic inspection of fall protection equipment…..  every 12 months"

The original line system could not be safely accessed from the roof hatch; it had been designed to "arrest" and required the use of extended rope and grabs, PPE equipment that requires advanced user training. Over the years ventilation cowls have become permanent obstacles and the original roof lights have gained in fragility - so protection against a potential fall here was a must.

Industry progress has seen the old fixing method of penetrating through the roof substrate and bolting back to the main structure become less popular, and nowadays has been replaced with the method of attaching anchor posts to the outer skin of the roof.

Fixing back to steelwork makes it hard to find the optimum place on the outer skin. Modern systems make it predictable and easier to seal.

However with the advent of composite panels – some with outer skins as little as 0.4mm – anchors can not be arbitrarily fixed at 10m / standard spacings without proven calculations. Moreover, the use of a “drill screw” in a thin gauge outer sheet material requires specialist knowledge with regard to its installation & performance.

QBM have tested the performance of anchor posts on both 0.55 & 0.4 steel sheets with startling results.  These applications aided the development of their system and calculations package - that is complies with both EN795 & the recently published “magenta” industry guide for horizontal life lines.

The unique SOTER end anchor facilitates crossing lines and allows people to pass each other while still being attached to the system.

Air leakage is now a major factor in building design; SFS wanted all possible measures taken to reduce potential air leakage and water ingress. Many anchor posts on the market require as many as 16 fasteners per post to secure them, that’s 16 potential leak points.   The second generation Soter posts need just 4 external fasteners, structural bulb tite rivets that yield up to three times more sheer strength and four times greater pull out from such a composite panel.

 In addition to these challenges the gutters require ongoing maintenance & periodical cleaning.

Current Health &Safety and CDM guidance stipulates that the design of roof safety systems to be as far up the safety hierarchy triangle as possible. The best way of designing a building is to have no roof hazards - and build parapet walls for example… the worst is to make provision for a fall but arrest it, so no hard comes to the unfortunate faller.  Somewhere between these extreme conditions is the deployment a “work restraint” option.  This comprises a guided line system that will allow an operative with minimal experience and appropriate PPE to perform his tasks in complete safety – typically he will never be closer than 2.3m from any possibility of a fall.

Structural bulb tite rivets offer three or four times better performance than traditional drill screws in this application.  Soter posts are fixed on top of the corrugation, away from the water, with 4 large rivets.  This means less fasteners and reduced risk from leaks.

Following and remaining with-in these guide lines, the most cost effective option to cater for all the various changes to the roof's conditions over it's lifetime culminated in a QBM decommissioning the old system and providing a simple "restraint" design with over 500m of line allowing for access to all areas of the roof regularly requiring maintenance, by even the most inexperienced operative.

Simple perimeter systems are safer, easier to use and can often be more cost effective than "arrest" designs.

The old out dated system gave way to a simple, functional and safer restraint design.  The whole project was completed in two days much to the satisfaction of everyone.

and those gutters are clean once more !