Developed over 30 years ago by a specialist team of cement chemists. the Triskell® Coatings were designed specifically to renovate and weatherproof aging asbestos fibre reinforced cement roof sheets. The Triskell® treatment is an in depth system that envolves the thorough preparation and over hauling of the roof followed by the application of the Triskell® coating, to provide a guaranteed roof coating which can be either the natural colour of the roof sheet or an attractive pigmented finish to give the appearance of a re­sheeted roof.

It was established during long term weathering tests that were carried out between 1934 and 1945, as to which asbestos cement type sheets, once weathered. can absorb up to 30% of their original weight of rainwater.

The absorption of the rainwater naturally leads to a decrease in weatherproofing properties and an increase in moss and fungal growth, which further exacerbrates the problems caused by the additional weight of the roof sheet. In addition the extended drying time of sheets can lead to damage by frost, causing cracking and delamination of the sheet surface.

The thorough preparation, repair, overhauling of fixings followed by the application of the Triskell® treatment. will provide a guaranteed extension of the lite for this type of roof.

Available in a range of colours the Triskell® treatment will improve the external appearance of the roof, which will achieve an aesthtically pleasing finish. Triskell® Coatings penetrate and bond with the sheet to seal the surface and improve water run off, retarding future moss and fungal growth. Vertical asbestos cement cladding can also be renovated with the Triskell Coating System.

Triskell® is a non-convertible paint system specifically designed for the renovation of asbestos cement sheets. Applied to a properly prepared substrate the system will give a smooth long lasting moisture permeable finish thereby allowing the substrate to breathe. preventing premature failure of the surface coating.


The use of approved contractors ensures that the work carried out is to Triskell requirements. They have developed the policies and procedures to meet the following standards, required before any work is carried out.

  • Health & Safety legislation and guidance
  • Preparation of method statements and risk assessments.
  • COSHH preparation and procedures.
  • Site safety and safe working practice.
  • Project management and quality control.
  • Cleaning and preparation of existing sheets, using high-pressure cold water rotary cleaning head in an enclosed box mounted on wheels to traverse the roof in a vertical direction.
  • Proper filtering and disposal of waste to a licenced waste site is a legal requirement.
  • Repair and replacement (if required) of damaged or leaking sheets and fixing bolts.
  • Application of Triskell treatment, by coating brush or airless spay.

Renovation Of Asbestos Cement Sheets

Triskell Treatment Specification

The quality of the preparation is crucial to the life expectancy of the system. The preparation should only be carried out by a Triskell® approved, competent contractor who has an intimate knowledge of both working with and working on asbestos cement roofs.

  • The cleaning of the roof must be carried out using high-pressure water with a closed box cleaning system.
  • A filtration system must be installed to prevent air rising entering the drainage system. Contaminated filter bags must be disposed of at a toxic waste site.
  • Badly damaged sheets or missing fittings should be replaced prior to the cleaning being carried out
  • Holes, splits and cracks must be repaired using the Triskell Flexible Repair Kit. Self-adhered bitumen based repairs are not acceptable.
  • The Triskell® Flexible Repair system repairs must be carried out to a thoroughly dampened sheet.
  • Under no circumstances should the reinforcing fabric be omitted from the system.

Application of the Triskell® System

The sheets must be clean, all repairs carried out and the sheets thoroughly DRY.

Natural System

Apply one full coat of Triskell Natural applied at approximately 4m2 per litre to achieve 40 micron OFT Allow 6 hours to cure.
Apply second full coat of Triskell Natural applied at approximately 6m2 per litre to achieve 30 micron OFT