For R1000
h
r
T
Find an expression for the ring force
required around the perimeter of a
rondavel roof to prevent the roof from
collapsing under its own weight. Then
determine the force magnitude assuming:
• Radius r = 3m
• Pitch h = 1.5m
• Thatch density  = 300kg/m3
• Thatch thickness t = 150mm
Email your derivation and answer to
sw.jacobsz@up.ac.za