We adhere strictly to minimum specifications for thatched roofs as drawn up by the South African Thatchers Association (SATA), the CSIR's Guide to Good Thatching Practise and the new SANS 10407:2004 on Thatch Roof Construction.

MATERIALS
Poles
All poles must be CCA treated and meet the SABS 457 Specification for Eucalyptus and Pine wood. Strict attention is given to SABS 0163:1994 Sections 1 and 2, Table 5 dealing with tensions for round poles.
Besides the quality requirements of Code 457, the poles must also meet aesthetic requirements, namely no excessive cracks or crookedness, and they must be clean.

Laths
Laths must also meet the SABS 457 Specification and must be of the Eucalyptus species, with the following requirements:
Laths must be reasonably straight. They must be bound with wire in three places in bundles of 10. Laths must have a uniform thickness throughout the length with a thin end of 20-30mm. No signs of bark must be visible and they must be clean. Required lengths are 3 m, 3,6 m, 4,5 m and 6 m.

Grass & Reed
Permissible thatching grass species are:
Hyparrhenia Hirta (Common Thatching Grass) or Hyperthelia Dissolutu (Yellow Thatching Grass) or Hyparrhenia Filipendula (Fine Thatching Grass). Cape Reed (Thamnochortus lsgnis) can also be used, as well as the reed Phragmites Communis/Australis. The grass must only be cut in winter and be thoroughly dry with a maximum moisture content of 10-15 %. The grass must have a minimum length of 900mm. No mould or mouldy odour may be present. Joints must not be loose of shrunken. Only straight grass, cut above the first joint, may be used.

String
Creosote-treated sisal twine or polypropylene heavy-duty string must be used. Should wire be used as a fastening agent, it must be galvanised or be chrome nickel of +- 1 mm thickness.

ROOF CONSTRUCTION
All roof trussed must be made in accordance with the details and design of a thatchroof specialist or engineer. Drawings should be available.
All carpentry work must be neat and finished off to a high standard.
Roof construction must slope at 45° with a minimum slope of 35° over attic/dormer windows.
Trusses must be spaced at a maximum of 700-800 mm apart.
The minimum eave overhang is 400mm from end of pole to wall.
The minimum poles diameter is 75-100mm up to a length of 9 m. A larger diameter must be used on longer poles.
All work must comply with the National Building Regulations.
In a span of less than 10m, all load points must be fastened with 12mm bolts, and with 16mm bolts on larger structures.
Anti-split plates of the correct size must be affixed to all sawn off pole ends.
There must be a minimum spacing of 150mm between the first and last three laths, and 300mm between the remainder. The laths must be secured with 75-100 mm nails to every truss.
A proper truss plan must be designed to carry a minimum weight of 70 kg/m2
No thatching may be started in a section of the roof unless that section of the pole structure is fully secured and completed.
All poles and laths must be varnished.

Grass
Grass must be cleaned of excess leaves and seeds, and the ends must be free of roots and straight. Grass must preferably be yellow in colour. A standard bundle of grass should have a diameter of 100-120 mm and a circumference of 400 mm.

Cape Reed
A standard bundle should have a diameter of 60-76 mm. The reed must have a minimum length of 1,2 m, and must be thoroughly dry and yellow in colour.

Underlay Grass or Reed (Spreigras)
If grass is being used as underlay, then it must preferably be of the species Hyperthelia Dissolutu. Grass must be thoroughly clean of leaves or seeds. It is important that the grass has a golden yellow colour. Standard bundles of underlay grass must have a diameter of 60-75 mm with a minimum length of 1,2 m. If Cape Reed be used as an underlay, it must be a golden yellow colour and have no more than 5% grey reed in content.

Ridges
Cement ridges must conform to the following requirements:
o A layer of 250 micron PVC membrane must be placed over the grass on the top.
o A reinforcing layer of 12 mm galvanised bird wire must be embedded into the 75 mm thick cement and sand mix cast on top of the PVC membrane. The cement ridge must be neatly formed, floated and finished, with a 75 mm thickness. (Mix 3 parts river sand : 1 part cement).
All cement ridges must be sealed with a waterproofing membrane.
Grass ridges must have a minimum thickness of 75 mm and be properly formed and secured with 13 mm galvanised bird wire.
Grass must be thatched and secured to at least the last two laths on the ridge.
All ridges must be will formed and have a sturdy appearance.

Thatching
Spray layer ends must be tucked in behind laths and must not to be visible.
Roofs must be thatched at a minimum angle of 45° with a minimum thickness of 175mm at a minimum of 35 kg/m2, which represents approximately 50 bundles of grass per square metre.
The maximum projection of grass ends must not exceed 25-50 mm after thatching is completed.
Grass must be thoroughly compacted and layered. No loose grass or loosely layered grass areas is permissable.
Thatching twine must be tightly fastened, no further than 100 mm apart as it is stitched around the laths, with no loops allowed.
Roof must be level and smoothly finished, and layers in the thatching must not be visible. No bumps or dents are allowed.
No loose leaves or grass stems must be visible.
Eaves can be finished at either a 45° angle or a horizontal level.
The overhang of the thatch projecting over the last lath may not exceed 300 mm.
The kick batten must be 30-50 mm thicker than the rest of the laths.
Wire - (3,15 mm wire or 2,2 mm steel wire)
Small reed bundles or thin laths may also be used in place of tension wire.

Lightning Protection
All lightning poles must be of manufactured galvanised steel pipe.
They must be erected in strict accordance with SABS Code 3 Lightning Protection for residential dwellings.