Every year 30-40 historic thatched buildings, out of an estimated 25,000 listed properties, are destroyed and lost through preventable fires. Unless drastic measures are taken to reverse the trend, in the next 25 years up to 1,000 properties, along with their unique historical record will be irretrievably lost. (Source National Society of Master Thatchers : Fire in Thatch Seminar October 2005).

A superb illustration of this was of a thatched cottage in Wiltshire which had been injected with UF foam between the thatch roof and the internal sloping ceiling.

The thatched roof caught fire (see photo below) and the foam stopped the burning thatch from collapsing into the interior and destroying the building completely. The delay provided by the foam gave the fire brigade enough time to deal with the fire. It was estimated that the foam prevented £70,000 to £80,000 worth of additional damage.

The Chief Fire Officer of Wiltshire at the time wrote:

"Having studied the nature and consequences of the fire, certain unusual aspects are noted which may have significance for others in the future.

From a fire fighting aspect, the operational personnel attending the fire were struck by the manner in which the roof members and ceiling remained intact and thus preventing the complete collapse of burning material into the first floor rooms.

This allowed the firefighters to clear the burning thatch from the roof and after examination of the roof structure, covered it with weather protective sheeting. The lack of damage to the upper floor level was most noticeable. It wopuld appear that this was in the main, due to an environmental heat insulation which had been installed in the roof area. This insulation consisted of UREA-FORMALDEHYDE foam being injected through the ceiling panels into voids between the roof joints and the underside of the thatch.

It was noted that this foam stayed in place during the fire asnd provided an effective insulation between the burning thatch and the roof timbers.

Only in areas where the injected foam had not effectively filled certain cavity areas, did the fire significantly damage the exposed timbers.

In the main, a good standard of protection to the roof members had been achieved and excessive spread of the products of vfire via the void areas prevented.

I would suggest that this material in this particular case significantly restricted the spread of fire into the roof structures, gave the firefighters extra time to carry out damage control and to remove the burning thatch.