Archetech Issue 23 2016 | Page 141

Thatched Roof – Fire Protection Thatching Advisory Services (TAS) - Overview Statistically homes with thatched roofs are no more likely to catch fire than those with conventional roofs if the owner is made aware of and understands the risk of thatch fire. However, if a thatched roof does ignite and is allowed to develop it’s almost impossible to control and the results can be devastating. Every thatched fire will vary due to factors such as weather conditions, location of property, thickness of the thatch etc. For over 40 years TAS has unrivalled expertise in the protection of thatched buildings and offer advice on the preventative and protective options available. We are often the first port of call for architects, home-owners, local authority building control departments and thatchers. The key objective of any fire barrier is to buy more time. A fire barrier will dramatically increase the chance of saving the majority of the building. Fire Retardant Sprays A survey into the cause of thatch fires revealed ejected embers and sparks as the main cause and all included the use of wood burning or multi-fuel stoves. Investigations showed that fires were reported within 30 minutes of a fire being lit or being re- fuelled. Fire retardant sprays should be applied by trained personnel using high-pressure specialist equipment to treat not only the thatch surface but also the thatch stems to ensure a degree of protection for a number of years. Several issues can increase the risk of the effects from ejected embers or sparks, these include: • • Spark arrestors – If not cleaned at least once a year they can clog up and will catch fire in their own right, which in turn could cause a thatch fire. Chimney height – The risk of a thatch fire is further increased when the chimney height has been reduced following many years of recoating works, this is more common with thatching materials such as long straw. The application should be carried out at a certain pressure using a specific tip spraying upwards into the thatch coat work at the angle of the roof ensuring penetration of between 50mm and 75mm. This will ensure the fire retardant is applied to both the surface and thatch stems. Thatch fire retardants should be a water-based solution of fire retardant and intumescent chemicals specifically formulated for the protection of thatch roofing. They should not contain any borates or borate-based additives. They must be environmentally friendly with no detrimental effect to plants or animals and of course have no adverse reaction to the thatch. TAS Thatchsayf Fire Retardant Spray can be applied as a standalone product or in addition to having a physical fire barrier system installed and should be reapplied every five years. Page 141 - Archetech Over the years we have forged close working relationships with many of the leading insurance companies, test houses and product manufacturers whilst further developing our range of fire barriers. Fire - Causes