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|
| The
consequences of burning wood inefficiently
can be disastrous to the fabric of
a chimney. The heat producing characteristics of wood burning are
not the same as fossil fuels, over 50% of the weight of the wood
is moisture in the form of tree sap or resin. Therefore wood burns
cooler and slower. This may at first appear to be a very efficient
fuel, however the following information will prove otherwise. |
|
THE
FOUR STAGES OF CREOSOTE
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|
1.
Condensate 2. Liquid 3. Solid 4. Friable
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| When wood
is burnt in a stove, it is common practice to reduce the amount
of air entering the combustion chamber in an attempt to save fuel.
This will cause the appliance to sulk (smoulder), this has serious
side effects.
Slowing the
burning process will cause the products of combustion (smoke)
from the wood to cool as it enters the chimney.
The smoke
will not maintain a high enough temperature, preventing it from
being driven up the flue at a sustainable velocity to escape from
the stack. The cooling effect causes condensation to form on the
inner surface of the chimney, and the sap/ resin turns the condensates
into creosote (a natural bitumous oil)
|
| The
condensates turn to liquid. The liquid creosote seeps into the mortar
joints and the masonry, the corrosive effects of the creosote then
destroys the masonry and mortar joints, in the same way as oil destroys
concrete garage bases. |
Varying
temperatures within the chimney cause the liquid creosote to heat
up and cool down, as it cools it solidifies on the internal surfaces
of the chimney the creosote quickly builds up, reducing the cross
sectional area of the chimney and in some cases blocking the flue
completely. The visual appearance of solidified creosote resembles
that of tar and many people refer
to it as tar build up. Solid-state creosote is highly inflammable
and serious chimney fires are a regular occurrence from wood burning.
Temperatures exceeding 2000C have been recorded from such fires.
|
| Stage
4 FRIABLE STATE CREOSOTE |
| When
solid-state creosote burns, all the volatile oils are burnt off
leaving a residue similar to a honeycomb, which is crisp and easy
to sweep from the chimney. However we would never recommend setting
a fire to a chimney to clean it, this would be a sure fire way to
become homeless. |
THERMOCRETE’S
CREOSOTE REMOVAL SYSTEM |
| Thermocrete`s
Creosote Removal Treatment will enable the chimney
to be used again and minimise the chances of a chimney fire. |
•
The process involves an initial sweeping of the chimney from the
top.
• Specialised chemicals are then
sprayed onto the internal surfaces of the chimney.
• The chemicals are then left
to react with the creosote for a minimum of seven days.
• If possible the appliance should
be used.
• After the chemical reaction
is complete it is then possible to remove the residue.
• The chimney is then tested.
• If any further problems become
apparent, this will be reported and any remedial works required
advised to the client. |
| BELOW
A CHIMNEY CHOKED WITH CREOSOTE |
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