Stop Chimney Fires in Thatched Properties

A quintessential “Chocolate box” thatched house is a unique feature of the UK country landscape. Add a glowing wood burning stove on a chilly spring evening and the picture becomes a rural dream for some lucky (or unlucky) families; that dream combination is not without extreme risk for the unwary.   A chimney fire is wholly preventable.   In a thatched property, a fire in the chimney can easily spread to the thatch and once alight thatch is very difficult, almost impossible, to put out.  The damage caused in dealing with a thatch chimney fire can be devastating.

Records taken over many years show March to June, is the most likely time to experience a chimney fire.  Peak times are during cold spring bank-holiday weekends, after the central heating has been turned off.

There are two causes of chimney fires, nesting birds and using unsuitable material as fuel.

Bird Nests

A determined pair of Jackdaws can fill a chimney with large twigs and sticks in a surprisingly short period of time.  Next time a fire is lit in the hearth below, the Jackdaws sticks, above, can catch fire. Burning twigs can be ejected onto the thatch.

An essential precaution is to fit a bird guard, your thatcher or local chimney engineer will advise. A clean bird guard indicates that properly prepared and stored fuel is being used.

Blockages & Chimney Fires

Water vapour combines  with other gases and particles going up the chimney and unless the chimney is kept warm, the condensation forms a creosote-like substance  which  hardens  to  form  tar  on the  surface  of  chimney liners  and  may  seep  into  brickwork  in  an  unlined  chimney.  The following picture is a blocked liner after only one year of burning chemically treated builders’ timber off-cuts.