We have the pleasure in introducing to you Micon THATCHSAYF, an innovative fire protection product for thatch roofs. The Building Technology Division of the CSIR (Council for Scientific and Industrial Research of South Africa) has been involved with research and development of fire retardant products for the past 20 years. Its most dynamic product, Micon THATCHSAYF, which took years to develop, is marketed and manufactured by Micon Coatings. This coating provides protection of thatched roofed structures against the ravages of fire, whether initiated by electrical short circuit, lightning or any other source of fire.

This fire retardant coating consists of a solution of fire retardant chemicals, intumescent and polymer. On application, evaporation of the water causes a surface skin to form, resulting in longer contact and better penetration of the fire retardant chemicals into the substrata. The mechanism of the protection is two-fold: on exposure to heat, the fire retardant chemicals react with the cellulose to form esters, giving a more stable base for the intumescent layer on the surface and the intumescent layer foams to form a protective char that restricts oxygen flow to the surface and also reduces the surface temperature of the thatch.

The esterification of the cellulose prevents the formation of levoglucosan, the backbone of the tarry substances that causes flaming combustion. These esters char, i.e. form carbonaceous residue on further heating and thus prevent flaming combustion of the cellulose. As the fire retardants used in the formulation stabilise the substrata, they provide prolonged adherence for the surface protection coating with the result that a very thin intumescent coating will still give good protection, thus cutting down on cost.

This invention differs from many conventional fire retardants, which rely on dehydration of the cellulose to form a carbon backbone when the volatiles are paralysed off. The protective coating is applied by an approved applicator using specialised equipment.

The protective coating is environment friendly as it is:

  • biologically acceptable
  • no flammable or harmful solvents are used
  • non-toxic before and during application
  • products of combustion are non-toxic

Micon THATCHSAYF is clear and does not alter the natural aesthetics of thatch, in fact, it prevents discolouration for a longer period of time. In addition, the coating improves compaction of thatch without hindering its ability to breathe, thus preventing bacterial and fungal growth. It is the only product applied to both interior and exterior thatching for maximum protection. This task is undertaken only by trained and approved applicators that are monitored by both Micon Coatings and the CSIR ensuring that the ASTM E108 specification is complied with.

On completion of a contract, Micon Coatings will issue a certificate to confirm the correct amount of product has been applied in accordance with the CSIR, ASTM E108 specification. On the same certificate, the expiry date is recorded. The interior of the structure should not have to be retreated for the life of roof.

As of the today, Thatchsayf is the only post erection fire retardant treatment tested in accordance with ASTM E108, a requirement of the SANS 10407 thatch roof construction specification. A number of the major insurance companies allow premium savings.




It is crucial that the thatch roof construction complies with good thatching practice, as fire performance is also dependant on the construction of the thatch. This ensures that when the roof is sprayed with Micon THATCHSAYF it will maintain its integrity in resisting the ravages of fire for sufficient time to allow fire-fighting services to arrive or for in-house fire fighting to commence.


Quality control procedures are kept of a high standard and all batch numbers of material are recorded for each contract and certificate.


Spraying Micon THATCHSAYF is undertaken by Micon’s approved and trained applicators ensures that correct pressure and minimum quantity of 1,3 litres per m² is applied to the thatch. Micon THATCHSAYF is easily applied by means of high pressure spraying equipment to both the interior and exterior of the roof surfaces. This ensures that at least 5mm penetration of the underside of the thatch (where compaction is much denser), and up to 75mm penetration to the outside of the thatch. It is important that the thatch roof is not disturbed after spraying and in this event re-application of the effected area is necessary to ensure complete protection.


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As the application of Micon THATCHSAYF is to provide vital protection in the event of a fire, Micon offers a certificate for each contract. The home owner, architect, developer, or building control officer can request this document that certifies supply of the product on site. The applicator also signs that the product has been correctly applied in accordance with the manufacturer’s specifications.

Certification Period – From date of application:

  • Coastal Regions >100km from the coast : 5 years (outside only, interior is valid for the life of roof)
  • Inland : 7 years (outside only, interior is valid for the life of roof)
  • Inland areas of high humidity (ie Vic Falls) : 5 years (outside only, interior is valid for the life of roof)


On exposure to heat the first stage of protection occurs when intumescent material foams and forms an insulating char on the surface limiting the heat flow and supply the of oxygen which supports combustion. The second stage of protection occurs when the fire retardant chemicals react with the cellulose and charring takes place, again having the effect of limiting the flow of oxygen.


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  • Fire Properties Test Method
  • Resistance to Ignition DIN, UL (modified), ASTM E-108, FireLab, BS 476 part 3
  • Weathering CSIR, UL (modified)
  • Rot Resistance CSIR
  • Tested by the CSIR report No BF010/020 Sept993
  • Tested by FireLab report No FTL 05/019


  • Viscosity: 16 secs F.C.4
  • Specific Gravity: 1,16
  • Drying Time: 2 – 5 hours
  • Full Cure: 4 Days
  • Solid Content: 47 – 49% /vol
  • Spread Rate: 1,3ml/m²
  • Shelf Life: 12 Months


Micon THATCHSAYF is an environmentally safe and effective fire retardant coating for the fire protection of thatched roofs. On exposure to heat, the fire retardant forms a protective char that restricts the oxygen flow to the surface and reduces the surface temperature of the coated base.


  • Tested in accordance with the CSIR, DIN, UL (modified), ASTM E108 requirements
  • Environmentally safe
  • Improves thatch compaction
  • Does not alter the natural appearance of thatch
  • Decreased insurance premiums


Micon THATCHSAYF is a water-based solution of fire retardant and intumescent chemical in a polymer emulsion binder formulated for the protection of thatch roofing. This combination provides dual-protection with the fire retardant chemicals penetrating the leaves of the thatch and intumescent, as well as some of the fire retardant chemicals forming a thin protective film on the surface of the thatch stems.


Micon THATCHSAYF does not change the natural appearance of the thatch and improves compaction without hindering its ability to breathe. In order to minimise water penetration it is crucial that roof slopes are 45 degrees. The main constituents of Micon THATCHSAYF consist of fertilizer type chemicals, i.e. phosphates and nitrogen compounds, and such are environmentally friendly, however high concentrations such as vegetation in the drip-off area depending on the amount of rain and thus dilution.