I f you travel through rural south India observing its architecture, you cannot miss the charm and elegance of thatch-roofed huts. Step into one and you will notice how cool the interiors are. Compare this to our modern city dwellings — where we spend a lot of money and energy to use engineered building materials and then spend more money and energy to cool the same mechanically.
Thatch roofing is a traditional roofing method that uses dry vegetation such as straw, palm leaves and water reeds to create a natural roof covering. Looking back in time, it has been used traditionally as a locally available eco-friendly roof cover worldwide. These dwellings date back even before the middle ages when it was one of the very few roofing options available before the onset of manufactured materials and transportation options in the late 19th century.
Fire safety
Since then, with continued modernisation, thatch was seen to be a ‘poor man’s’ material and associated with mediocrity.
This resulted in the art fading over time and the craft disappearing in our modern cities. One more hurdle in using thatch in modern construction has been the assumption that its is prone to fire.
However, thatch is no more prone to fire than any other material. Thatch in fact, smoulders and does not burn. Its installation is done in a minimum thickness of about 9-12” which provides the density to slow down spread of smoke. Today there are also several techniques that are used for fire prevention in thatch.
These include: an aluminium barrier foil beneath the thatch, fire retardant sprays and non-combustible rock-wool slabs to the underside of the thatch.
Given the current scenario of critical environmental degradation and climate change there seems to be a revival of alternate, building materials. In this regard the use of thatch is one such holistically sustainable option for the following reasons:
Water resistance: Water reed thatch has a natural resistance to salt and liquid and when installed at a slope of over 45 degrees, is an ideal waterproof roof even in coastal areas prone to heavy rains. The outer layer of these reeds has a natural waxy coating that repels moisture.
Insulation: Thatch is highly insulating and is one of the few naturally occurring insulating materials, its insulating value being more than three times higher than a typical RCC roof with weathering course. This will further reduce the need for mechanical conditioning.
Aesthetics: Thatching is a skilled art that is highly aesthetically attractive and charming and can be innovatively combined with modern materials in our contemporary designs.
The author is founder, Green Evolution, sustainable architects
