Thatch Roofing - Innovations in Fire Protection

'How very little since things were made, Things havebetween the building and its plot boundary line.o
altered in the building trade' -Rudyard KiplingREDUCTION OF COMBUSTIBILITY
If one look at the quote above one can deduct thatFire retardant chemicals
there has not been a lot of innovations in theMany fire retardant chemicals are available these
thatching industry, there has however been hugedays that can be applied to thatch by immersion or
advances in the fire protection of the thatchingspraying, but as these chemicals are generally water
material. Modern laying techniques also eliminate thesoluble they are, in time, largely washed out by rain
exaggerated fire risk that many people fearas they do not penetrate the material but only form
regarding thatch. Nowadays various fire blankets area surface coating.
placed in between the thatch and with the correctA lot of exposure to the sun will also gradually
compaction the fire risk is virtually eliminated and withevaporate the chemicals and might leave the top
the use of lightning conductors, thatch is no longerlayer unprotected.
the hazardous material of the past.o PREVENTATIVEFire resistant blankets
MEASURESA protective, noncombustible membrane can be laid
Lightning protectionunder the thatching grass to act as a blanket
Lightning conductors should always be installed topreventing the spread of fire between the thatch
protect the thatched buildings. For single masts thelayers. Materials that are generally used for such a
angle of protection is 45° from the highest pointpurpose is aluminum, building paper or glass fibre. The
downwards and one should make sure that thedisadvantage of such a measure in warm, humid or
whole roof is covered by at least one meter abovehigh rainfall areas is that because of the impervious
the roof of the building. For a high risk zone ofmembrane or blanket, air flow between the thatch is
lightning for example on sloping ground or on a hill,restricted and will enhance the growth of destructive
the angle of protection is only 30° from thefungi. To allow air flow through the thatch to avoid
highest point downwards along the pole and naturallyfungi growth the chosen membrane should be
the lightning conductor will have to be a lot taller orsufficiently perforated.o FIRE FIGHTING FACILITIES
multiple conductors can be installed. When more thanSoaking with water
one lightning conductor is installed, the angle ofPerforated horizontal pipes can be provided on each
protection between them is 60° from theirside of and running parallel to the ridge, controlled by
highest points downwards along the poles.stop taps at ground level. The pipes can be of
Bindinggalvanized steel or copper, perforated with holes at
For lightning protection purposes, it is stronglysufficient intervals along the length of the pipe to
recommended that galvanized steel wire should notdischarge water over the roof surface in the event
be used for binding the thatch, and rather a suitableof fire. Alternatively a horizontal pipe may be run
natural material should be used. Poplar and wattleinside the roof at the ridge, with 'spreaders'
sticks are commonly used and some use cane orprotruding through the thatch at sufficient intervals.
thatch strands. Tar treated string should not be usedSuch installations can be used to soak the thatch in
for binding as this can create a fuse-like effect in thethe event of a fire risk. A high rate of water
event of fire.discharge is needed for this to be effective and will
Chimneysnot be able to run of a domestic water supply.
Chimney stacks should be constructed in such awaySpecial arrangement will need to be made with the
that the outer faces in contact with the thatch dolocal council for such an installation.
not become hot. A full brick thickness (220 mm) isOther
normally sufficient to satisfy this requirement. AllThere are two schools of thought about the value of
mortar joints in the stack must be properly filled. Theswimming pools as a source of water supply for fire
top of the stack must extend to at least 1m abovefighting. Some local authorities consider that a pool
the highest point of roof and a spark arrestor,can be useful if located near enough to the house
(stainless steel wire mesh), fitted close to the top,and with unrestricted access for the fire brigade.
covering the full width of the flue, must be built intoHowever, some specialist organizations believe that
the flue around the edges to prevent sparks flyingthatch burns so rapidly that the fire brigade can
out and possibly ignite the roof.rarely reach the scene before the fire has got a hold
Cabling & Servicesand that initial use of water from the brigade's unit
Electrical power supply and telephone cables shouldtanks would be quicker than using a swimming pool
enter the building by means of underground ducts,supply.
and all electrical wiring in the roof space should be runA long-handled metal rake should be provided in an
in screwed metal conduit, with all junction boxeseasily accessible place, for pulling down smoldering
properly sealed.thatch from the roof. The handle may be fitted with
Refusea suitable clip to which the nozzle of the hose pipe
Combustible material should not be allowed tomay be attached, thus improving the reach of the
accumulate near the house. A number of thatchedjet.
roofs have, in the past, been set on fire as a resultEven when all these precautions have been taken,
of the burning of garden refuse in the vicinity.the occupant of a thatched house must always
Adjacent buildingsexercise care when handling open fires in or near the
Sufficient space must be allowed between buildingshouse e.g. when preparing for a bbq or burning
to prevent fire spreading to the thatched buildinggarden refuse or if fireworks are being discharged in
from adjacent buildings and vice versa. Somethe vicinity.
countries' regulations calls for at least a 15m distance