Thatch fires

[88v8]

'The causes of chimney fires in thatched roofs are being investigated by scientists at the Fire Protection Association's base in Moreton-in-Marsh, Gloucestershire.
Iain McCaig of Historic England, which is involved in the study, said the first phase - looking at the risk posed by sparks, was now complete.
"Evidence suggests that most thatched roof fires occur shortly after the wood burner has been lit," he said.
http://www.bbc.co.uk/news/uk-england-wiltshire-34183381

Only an issue when the thatch is dry. Not too difficult to pop out at such times, shortly after lighting up, and check that one hasn't set the place alight.

Ivor

shame it's not being investigated by Thatcham

 

[atticman]

"Investigated by Thatcham"? - that would be alarming!!

Sorry. :?

 

[garnett]

Interesting - this information need careful reading as it could contradict advice that is given in Devon and Somerset. It is important to remember that there are two separate types of thatch in the UK. Long Straw in the east / centre and combed wheat read in the west. The chimney junction and resistance to sparked and transmitted heat is different. This is in the middle and it also gets complicated because government advice after the war said that long straw was better so some roofs got changed over! That makes a lot of sense with the wood sap collecting within the flu liner and the wonderful insulation that the thatch gives over 10 feet of its length. I suspect that if the full tests were read they would say much the same thing.

The horrible ones are the fires that start within the thatch when an unlined flu touches the chimney stack and created a hot spot. You often don't know that the roof is alight for a couple of hours until it has reached the opposite end of the building. We have so much thatch in Devon that they have strategically place fire tenders with CAFF Foam Lances to inject into the thatch.

I would strongly recommend that you treat this article with caution and speak to your local fire and rescue people who will understand the type of thatch in your area. Lined flues installed by HEATAS Engineers are vital along with spark arrestors. Without them you are probably not insured!

Garnett

 

[formerly known as]

don't forget water reed in Norfolk.

the current advice is that spark arrestors can be a problem - they cannot be easily cleaned and can themselves catch light.

heat transfer and electrical faults get my vote as the main causes.

flue liners allow the sparks to exit far more readily than a standard flue, so, in my opinion, a well pointed and parged flue lining would be the ideal although impossible to ensure; perhaps someone needs to look into the 20th c method of stabilising stacks with grout set in a temporary flexible shutter - this lining technique could be used to reinstate pointing and parging, although with an insulative sulphate resisting mixture that will not impede permeability.