Thatching Fire and Safety

Fire protection is a very important consideration for owners of thatched properties. KS Thatchers offer the following options;


Magma Firestop & IMW 435

These have been designed and tested specifically for use on thatched buildings and produced to ISO 9002 standards. Magma Firestop is a water repellent external fire retardant that can be sprayed directly onto the surface of the roof. IMW 435 is designed for internal use and can be sprayed onto the internal surface of the thatch and the supporting timbers.
By applying Magma Firestop, household insurance premiums can be reduced to a similar level to that of a conventional brick and tile property.


Within the fire retardant there is a special coating which helps to waterproof the thatch. This impregnation product itself cannot be washed out and acts as a special protection against leaching. Tests show that protection should last for up to 10 years. This time frame could be longer with thatch due to the fact that the solution penetrates into the ‘dry zone’ when applied, and therefore, is unaffected by subsequent weathering until the roof wears back.

Thatch Foil

Thatch foil 341 is a heavy gauge aluminium foil specially selected for its combination of strength and fire resistance, which acts as a thermally reflective insulator. It is applied in exactly the same manner as roofing felt and contains no flammable materials. Thatch foil has excellent insulating properties, reflecting over 90% of radiated heat. However, should only be used in conjunction with thatchbatts and does not act as a stand-alone fire barrier.


Thatchbatts are non-combustible; high quality, resin bonded lightweight Rockwool slabs which are fitted between the rafters, supported from galvanized steel brackets. Thatchbatts are designed to provide fire protection to the underside of thatched roofs on new buildings and/or extensions to existing buildings. They will also provide thermal and acoustic insulations as well as a one-hour fire rating.

Thatch Firewall

This product provides a one-hour fire barrier. It is fixed between the thatch & roof construction, laid horizontally across the rafters. In event of a thatch fire that thatch is sacrificial and untreated.


We will be happy to provider further information and advice on fire protection. Contact KS Thatchers to discuss your requirements.

Just a line to say many thanks to the team for doing such a lovely job here. The cottage really does look rather splendid with it’s new ‘top hat’ and several people have stopped to admire the work carried out. We’d also like to say a special thanks to the boys, who were always sunny, bright and polite. They really are a credit to their profession.
— Customer in Longstock