SA Roofing November 2018 // Issue 106 | страница 22

FEATURES
A thatch roof boasts a lifespan of between 25 and 30 years and requires a service twice in its lifetime.
Thatching to last
The fire safety of a thatch roof starts from
the planning and design stages, advises the
Thatchers Association of South Africa
(TASA). First and foremost an approved,
certified and qualified contractor should be
employed to administer the construction.
Unfortunately, we were informed that less
than five thatching contractors are certified
by the South African Technical Auditing
Services (SATAS). The thatch roof industry
is a specialised field and choosing the
cheapest contractor might be the most
expensive mistake an owner can make.
When installing, the thatch must be clean
and cut during the winter season according
to specifications. After the grass has been
cut and loosely bundled, each bundle is
shaken vigorously to dislodge all loose
material. The bundles are then cleaned by
passing a sickle through them, working
from top to bottom. Grass bundles are
between 75 and 100mm in diameter. These
are each tied with a thong of twisted grass
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NOVEMBER 2018
CLADDING // CONCRETE // INSULATION // STEEL // THATCH // TIMBER // TRANSLUCENT // WATERPROOFING // COMPONENTS
or with twine and packed in heaps. Thatch
that isn’t cut in season may rot over time.
Cutting before winter deems it immature
as it is full of seeds and leaves. The grass
boasts a resin layer when it is mature,
which assists in keep moisture out. Cutting
it in the growing season strips the grass of
this resin, leaving the thatch unprotected
from moisture and therefore susceptible to
rot. Thatch is cut in and out of season
because contractors may have limited
funds and possibly don’t have the correct
facilities to store the grass.
Once the thatch has been cut and
cleaned, it needs to be sundried for a
minimum of seven days before bundling
and placing in an upright position to dry
properly. This process would also apply to
re-thatching or servicing a thatched roof. A
roof being serviced should undergo a pull
and combing process. This process must be
well supervised since inexperienced or
uninformed contractors could take
shortcuts that could destroy the roof. Some
contractors comb the roof and the thatch
that is combed out is then pushed back –
this messes with the compaction and
alignment of the thatch and therefore
bends it.
As soon as the thatch is ready for
installation, you should consider that it is a
living breathing material which needs to
continue doing as such. The material
breathing works towards preventing
rotting. There are preventative measures
that can be taken to avert animals from
getting inside the roof again, it is the
compaction together with a rational design.
Systems that can be used to prevent animal
infestations and fires include drenching,
fire blankets, spark arrestors, bird mesh,
sprinklers, smoke detectors and more.
A thatch roof has a lifespan of between
25 and 30 years and it only needs to be
serviced twice in its lifetime. This is true for
roofs that use quality material that is cut
according to specifications. According to
research, there is a Cape reed roof that is
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