Thatch Evolution

Please note, click to expand the sub-sections below.

New Thatching
  • Rafters and roof trusses will be constructed insitu at 45° with poles of diameter 100mm - 125mm (Pole centres 800mm between roof trusses and Adequate cross bracing will be provided.
  • Structural junctions will be bolted with 12mm galvanised rods. Please note that in terms of the SABS standard of measurement the pole diameter specified relates to the top or thin end of the pole.
  • All poles will be CCA treated and conform to SABS standards.
  • The battening will be CCA treated Xingu's (laths) at 250mm centres.
  • The thatching will consist of frost dried Drakensberg thatch grass laid to the thickness of 175mm and tied with a double layer of tarred sisal twine.
  • The sprei laag (internal layer) will be selected long stemmed thatch.
  • A concrete ridge capping will be constructed with the appropriate waterproofing and reinforcing wire.
New Thatching
  • The thatch under the capping will be patched where necessary
  • New 250 micron plastic will be laid
  • Wire mesh will be placed over the plastic to reinforce the cement capping
  • Cement capping will be laid to profiles from the bottom ridge capping up to the rondawel ridge capping leaving the two joined neatly.
  • The profiles will be removed on completion of the work and the thatch tidied wherever disturbed during the process.
New Thatching
  • The existing thatch roof will be combed prior to receiving a new layer of thatch to remove all decayed matter.
  • A fresh layer of Drakensberg thatch (Hyperina Hirta ) will be stitched to the roof to a finished thickness of 175mm using double stranded tarred twine.
  • New capping will be placed on completion of the re-thatching – as per the specification above.
  • The thatched section discussed will be combed after the capping has been laid to yield a neat finish.
  • The eaves line will be knocked up to ensure a level final result.
New Thatching
  • The combing process is designed to remove all decayed material on the surface of the thatch as well as all the decayed thatch.
  • The thatch is also re-compacted and replaced where necessary i.e where it has fallen out under the ridge capping and next to the chimney at the rear of the house.
  • Failure to comb the thatch, when required, causes the thatch to rot quicker as the excess decayed matter on the outside acts as a sponge which retains moisture for longer than would normally be the case thus keeping the roof wet for longer than normal.