What is the recommended fire retardant treatment?

Dipping the thatch in a solution containing 60 g/l each of diammonium phosphate and ammonium sulphate, followed by the application of a stabilized mud plaster (Clause 5.2).

What is the minimum recommended slope for a thatched roof?

The roof frame should have a slope not less than 35 degrees to ensure proper water drainage (Clause 6.2).

How is the thatch protected from rot and termites?

By treating the material with a preservative chemical like a 40 g/l solution of Copper-Chrome-Boron (CCB) as per IS 1003 (Part 2) (Clause 5.3).

What is the specified thickness for the thatched roof?

The compacted thickness of the thatch at any point on the roof should not be less than 150 mm (Clause 6.3).

IS 12506

: 1988

Code of Practice for Improved Thatching of Roof with Rot and Fire Retardant Treatment

CurrentSpecializedCode of PracticeArchitectural · Building Construction Practices incl. Painting, Varnishing

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This standard outlines the code of practice for improved thatching of roofs to enhance their lifespan and safety. It details the selection of materials, methods for treatment to make them resistant to rot and fire, and the proper construction techniques for laying the thatch.

Code of Practice for Improved Thatching of Roof with Rot and Fire Retardant Treatment

Quick Reference Values

Minimum compacted thickness of thatch150 mm

Minimum roof slope35 degrees

Fire retardant chemical solution (Diammonium Phosphate)60 g/l

Preservative chemical solution (Copper-Chrome-Boron)40 g/l

Minimum end lap of thatch layers150 mm

Maximum spacing of battens300 mm

Practical Notes

The fire retardant treatment's effectiveness depends heavily on keeping the thatch dry. A steep roof slope (over 35°) and regular maintenance are critical.

Chemical treatments must be applied thoroughly and evenly before the thatch is laid. Use appropriate Personal Protective Equipment (PPE) when handling chemicals.

The final roof should have a smooth, compacted surface to facilitate water runoff and prevent wind damage.