When roofing with an open flame
a gas burner is used.
It produces long flames and
can easily start a fire
in materials nearby,
or lead warmth
through cavities, ducts and so on.
This is especially dangerous in older buildings
where isolation often consists of
wood shavings, newspapers or other material
that can easily ignite.
Metal can also lead warmth
and start a fire at a completely different
place than on the roof.
Therefore you should bring tools
you can use to remove planks and tiles with,
since these places are difficult to reach.
Roofing with an open flame is also
regulated in the safety regulation:
It is prohibitied to use open flame
on lined and ventilated wooden roofs.
On compact roofs open flame is permitted
if flammable insulation is protected with
at least 30 mm non-combustible insulation.
There must be a safety distance of 60 cm
to parapet, cornice, ducts and so on
if thes consist of combustible material.
Hot air is a lot safer than
open flames.
Here the warm gas and air is
shielded in a chamber.
The biggest risk with this equipment
is that it produces a lot of carbon dioxide
that displaces the oxygen.
When you are done and turn off the equipment
oxygen-rich air rushes back,
which can lead to ignition.
Roofing can also be done with hot bitumen.
Gas-fired bitumen boilers are used
in order to heat the asphalt to 200 degrees celcius.
Here the bitumen boiler is the main risk,
not the roofing.
It can overheat,
causing the bitumen to ignite.
Or warm bitumen can spray out of the boiler.
When using a bitumen boiler you must follow these rules:
The bitumen boiler must be placed on a non-combustible
and level base,
for example in a vessel,
that can hold at least half of the
content in the boiler and is at least
30 cm wider than the boiler on all sides.
The boiler must always be placed
where it cause the least possible risk
if it overheats or tips over.
The boiler must be supervised at all times.
Flammable material in the vicinity must be removed.
On sloping grounds the boiler must be at least
15 meters from flammable material.
And at least 5 meters from
buildings in non-combustible materials.
Gas cylinders must be placed at
least 5 metes from the boiler.
Fire in a boiler must
never be put out with water.
If water comes in contact with
the burning bitument,
it can be thrown out of the boiler
with great power.