Electricity + Control January 2019

EARTHING + LIGHTNING PROTECTION

DEHN Africa launches DEHNinsure

DEHN Africa has been involved in a number of installations of lightning protec- tion systems for thatched roofs and, in what is believed to be a first in South Africa, has launched a new and exciting initiative, which combines the company’s expertise in lightning protection with a holistic insurance offering.

Take Note!

Protective measures against fire are essential for thatched roofs. These days, the nature of lightning protection for thatched roofs has improved.

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T hatched roofs are an aesthetically pleasing option for game lodges and other buildings looking to cultivate a rural feel, but they re- quire significant maintenance, including protective measures against the possibility of a fire outbreak. At the same time, because they are so potentially flammable compared to other types of roofs, the insurance requirements on buildings with thatched roofs can be onerous. For numerous insurance companies, a thatched roof is regarded as a non-standard construction – in contrast to roofs made of tile, slate, concrete, asbestos, metal or zinc, which are deemed to be standard – and this is taken into account when de- termining home insurance cover and premiums. The insurer will expect you to take steps to reduce fire risk. These steps include the following: • Have your thatched roof installed and main- tained by professionals. • Protect it against fire, using fire-retardant ma- terials that can help to delay the fire’s spread over the roof, and make sure that any chim- neys are protected. • Have fire extinguishers strategically available, and service them annually. • Protect against lightning: The direct lightning flash density is high in large areas of South Af- rica, and can cause fires. DEHN Africa managing director Hano Oelofse notes that traditionally, external lightning protec- tive equipment for thatched roofs has involved the use of a free-standing lightning mast, which must be higher than the thatched roof. “The idea,” he says, “is that the lightning flash

will ‘seek’ a pathway to the ground and thereby discharge itself through the lightning mast; pre- venting a flammable roof from being struck by the lightning instead. However, the masts are highly visible which defeats the object of having a thatched roof that blends into the environment. The mast has to be installed at a height derived from the lightning risk assessment whereby the correct angle of protection is given according to each lightning protection level. The lightning mast must be high enough to cover the enire building. “A free-standing lightning mast must be earthed and bonded sufficiently, and also needs to be ser- viced annually, as insufficient bonding and earthing may lead to flashovers to the thatch roof and haz- ardous step and touch potentials around the mast. A mast alone is not sufficient to prevent damage to the equipment in a home, so a separate surge protective device is still necessary.” Today, however, the nature of lightning protec- tion for thatched roofs has changed with improve- ments in technology. “For some years now, DEHN Africa has provided lightning protection system (LPS) components for use specifically on thatched roofs,” Oelofse says, “and our high-voltage-resistant insulated (HVI) light- ning protection system, which is compact and neat, removes the need for a 30+ metre lightning mast. The HVI system is far less visible to the naked eye and arguably provides better protection from a light- ning strike than a thirty-metre mast. Plus it is ac- cepted by leading insurance companies.” Oelofse says that, given the technical expertise offered by the HVI technology, and the company’s confidence in its product, DEHN Africa is now

"A mast alone is not sufficient to prevent damage ... a separate surge protection

device is still necessary."

Enquiries: Hano Oelofse. Tel. +27 (0) 11 704 1487

24 Electricity + Control

JANUARY 2019