FEATURES
They have conducted work for a variety of clients ranging from
the Sandton Fire Department in Johannesburg to the Kruger
National Park in Mpumalanga.
The company also trades as Thatch Protection Africa for the
business’s cross border clients. Heatlie says since their
inception, TPS has never suffered a loss of a roof to fire caused
by lightning strikes, electrical faults, arson attacks, veld or
bushfires, gas or braai fires.
Although the construction of roofs to buildings requires
approval by local authorities, most lapas or recreational
buildings are erected without any approval of building plans –
another knock to the industry. Building without prior approval is
normally a result of ignorance by the respective owner as all
structures erected in South Africa must be approved by the
respective local authority in terms of the National Building
Regulations (NBR).
Very often clients are told by these thatching contractors that
minor structures do not require any approval from local
authorities. Whereas thatching contractors who follow best
practice would require approved plans prior to the erection of
any thatch structure, and their structures would also comply
with the necessary standards.
A burning question:
to spray thatch or not
SA Roofing has learnt that the thatching industry has incurred
incalculable damage by certain chemical substances sprayed on
thatched roofs that are not tested or tested incorrectly. Should a
chemical substance be applied for the fire protection of a thatch
roof, SANS 10400-T makes provision for the testing of all
combustible roofs, including thatching.
The test method SANS 10177-12 (previously known as ASTM E
108 – an American standard used mainly for roof shingles which
has now been upgraded to ASTM E 108.17) not only addresses
the fire properties but also the durability of the application by
means of an accelerated weathering test to observe the effect and
the effectiveness of the chemical application of the thatch layer.
In the absence of a South African test method for the fire
safety evaluation of roofs containing combustible materials, this
test method was adopted by the South African Bureau of
Standards (SABS) as part of its fire test protocols. In addition to
the fire testing, this test evaluation protocol also looks at
durability and the effect of chemical treatment of the thatch
protective layer and the short-term test results also require
long-term exposure confirmation.
The effects of non-tested or incorrectly tested chemical
substances to thatched roofs, or the application of chemical
substances to bad quality roofs, is a major concern. FIRELAB
owner Kobus Strydom says they have rejected a test thatch roof
that was meant to be sprayed with chemical treatment because
it was obvious that the grass used for the construction of the
roof was cut pre-matured only a few months prior to erection.
“This means that the thatching material didn’t meet
specification requirements,” says Strydom, adding that the
quality of the thatch has a big influence on the lifespan of the
roof and not just the chemical treatment. “The roof would have
rotted even if it wasn’t treated with a fire-retardant product.”
Chemical manufacturers, suppliers and applicators say that the roof
should be sprayed inside and outside to prevent fires as they can
either ignite from the inside or as a result of heat exposure on the
outside. The properties of the product after application should not
affect the natural air movement through the thatch layer as this has a
negative result on the life expectancy of the thatch layer.
“Thatch is a living and breathing material which should be treated
accordingly,” says Michael Howard, manager at Mic