Restricting the Spread of Fire

It is preferable that all thatch roofs should be separated from the roof void by a fire resisting barrier, this ensures that any fire is easier to extinguish, and the building would suffer less damage from firefighting water.

The separation can take the form of "Masterboard", "Supalux" or similar proprietary fire resisting board. The boarding can either be applied under, between or preferably over the top of the rafters, as this provides a better fire tight roof. The disadvantage of the last method of course, is that the boarding can only be applied before the thatch.

The roof access should have a hatch of at least 900 mm x 600 mm, and should be able to withstand the passage of fire for at least 30 minutes.

Combustible materials should not be stored in the roof space.

Fire Retardant Treatment

In the past the practice was to soak new bundles of thatch prior to installation with a fire retardant solution. However for reasons of practical difficulty, on site quality control and fears that the treatment would shorten the service life of the roof, the practice has largely died out.

The process has generally been replaced by a sprayed external surface coating of fire tested silicon based compounds. Due to the leaching effect of the weather, and natural wear the life expectancy is guaranteed for just ten years, with possible re-treatment after five years.