Clip & Comply to 18th Edition Regulations
The requirement of IET’s 18th Edition, Chapter 52, that cables must be supported against their
premature collapse in the event of fire, is for many stakeholders a long-awaited stipulation to
address a critical fire-safety issue, but has others wondering ‘why?’ and ‘how?’ Such queries we
put to D-Line, the Newcastle-based cable management experts, who invented the first fire-rated
clips for use either direct-to-surface or in pvc trunking installations.
To see the full range of D-Line complaint clips click here
Keep reading to find out more!
Can D-Line summarise the background to this new requirement?
Of the twelve firefighters killed at work between 2005 and 2015
in UK, two-thirds were victims of fatal cable entanglements - those
deaths wouldn’t have occured if cables had been supported with fire-
safety in mind. In temperatures up to 900ºC, plastic systems could
not prevent cables dropping ‘to make impenetrable webs’, ‘molten
sheaths that stuck…’ and made death-traps amidst ‘heat like jet-
engines’ in ‘zero-visibility’. Coroners reports describe the horrific
consequences of cable entanglements. In July 2015 an amendment
to 17th Edition required non-combustible fixings to be used for all
new surface cable installations on ‘escape routes’. Because fires
occur wherever, the 18th Edition has extended the requirement to
all new cable installations… a potential life-saving development.
To clarify, must all new cable installations be secured in noncombustible ways?
Yes. Note, steel fixings and containment-systems can typically
withstand temperatures exceeding 1000ºC for at least 2 hours;
intended to afford sufficient time to evacuate densely populated
Installations relying on common plastics will melt at approximately
150ºC. In fires, PVC wall-plugs, plastic clips and ties, and plastic
cleats fitted direct-to-surface, all cause cables to drop by offering
inadequate support. Similarly, every length of surface-mounted
PVC trunking and conduits needs to be secured by non-combustible
fixings, so long after they disintegrate the cables will remain in-situ.
Are all metallic clips suitable for use?
Not necessarily. While mild-steel is suitable, almost half of metals
will melt at lower than 500ºC. Surety is best proved by tests. British
fire-test labs test fixings up to 970ºC for 2 hours, applying vibrations
to installations and water sprays too, to simulate fire conditions in
accordance with BS5839pt1 benchmark. For peace-of-mind and to ensure fit-for-purpose, stakeholders
should beware of untested products and alloys of variable
compositions from batch productions that can offer no performance
guarantees. Aside the heightened awareness of fire-safety generally,
at D-Line we trust a legacy of lives lost can be that standards are at
How should non-combustible fixings be installed?
Cables should be secured in accordance with cable manufacturers
guidelines. For horizontal cable installations the rule-of-thumb is
generally 300mm spacings for cables up to 8mm diameter, and
400mm for vertical installations. Bigger cables can sometimes
be spaced wider. It is important to note that wider-than-recommended spacings
compromise cable integrity, and cable performance is fundamental
to the regulations. From specially commissioned testing we know D-Line Safe-D
products can be fully-loaded re cable weight, and spaced on both
walls and ceiling planes at 500mm centres, while still holding cables
securely. However tempting, the wider spacings can increase risk
of cables sagging, which over the time of a fire increases risk of
short-circuits… when power to alarms and lights might be critical.
Consideration must be given not only to surface clip capabilities, and
for due diligence only fire-tested certified fixings should be used as
part of a complementary fire-rated cable management ‘system’.
Are such fire-rated cable management systems available?
D-Line offer a full range of innovative and market-leading solutions,
available from all leading wholesalers. All are fully tested for compliance with BS5839pt1 and to satisfy
new 18th Edition regulations, in conjunction with D-fixing screws
also. These screws have subtly-domed heads that optimize space
within the Safe-D Clips, and 40mm length that embeds to offer
exceptional pull-load resistance and load-bearing.
D-Line’s range is ideal for direct-to-surface fixing or for installation
in pvc trunkings up to 50mm wide. All are user-friendly, exceptionally
quick-to-install, with value-added features, and very competitively