African Design Magazine ADM #35 November 2017 | Page 34

For decades, people have been using thatch to create durable, beautiful
roofs for their homes. This practical form of roofing is now widely used
in both rural communities and urban developments, both commercial
and residential. Thatched roofs can be aesthetically pleasing, especially
where there is a desire to make the structures 'blend' into the
environment. However, this beautiful roof is also infamous for its
vulnerability to lightning strikes.
As outlined by the South African National Standard, SANS 10313, thatched roofs
are said to be far more susceptible than any other roof type to catching alight as a
result of a lightning strike.
It is no longer necessary to install a 30 metre long mast as the only option for
lightning protection for residential or commercial thatched roof structures. DEHN
Africa relies on an external lightning protection system called HVI (High Voltage
Insulation), which is practical, easy to install and far more aesthetically pleasing
than the mast technology. It blends into the environment and does not require
concrete foundations and construction techniques, as compared to the mast
technology.
South Africa has a number of provinces that are prone to higher incidents of
lightning strikes, and Gauteng, Kwazulu-Natal, Limpopo, Mpumulanga and
Northwest Province have some of the highest ground flash density in South Africa.
These areas are synonymous with lodges and bushveld homesteads and hotels.
Buildings with thatched roofing are most susceptible to lightning strikes and due to
this increased fire risk, insurance cover can be quite a struggle.
Hannes Ackermann, managing director at DEHN Africa, points out the enormous
loss to property sustained in the Cape St Francis fires of November 2012, in which
around 80 thatched roof residential properties were destroyed or badly damaged
by a fire that very quickly raged out of control. Ackermann notes, “While this fire
was not caused by lightning, it a ests just how flammable thatched roofs can be
and how quickly they can be set alight without proper protective measures in
place.”
The Cape St Francis fires were a big story in the insurance industry, and it is on
record that a large percentage of insurance claims on thatched roof houses are
unsurprisingly fire-related, and that a house can burn to the ground in 10
minutes. Therefore, from an insurance perspective, the claim often becomes a
total loss.
Ackermann says, “The 2012 St Francis fires incident indirectly reiterates and
confirms the necessity for owners of thatched lodges, hotels and residences to
invest in adequate lightning protection, particularly in areas of high flash density
lightning areas. technology on offer in the market for external lightning protection.”
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