Though the S.A. building regulations does not provide extensive detail in thatch construction - please read through the below guide from the Thatchers Association of South Africa (TASA) for more guidance.
Thatch Construction Guide available through the publicly available link: http://www.sa-thatchers.co.za/wp-content/uploads/2016/04/GUIDE-TO-THATCH-CONSTRUCTION-IN-SOUTH-AFRICA1.pdf
