Duromastic M17 is a single pack, clear polymeric sealer specially designed to penetrate and encapsulate the cement and asbestos dust fibres.
Duromastic M17 is best applied by airless sprayer at a rate of approx 4 sq metres per litre, per coat. 2 coats are recommended. Duromastic M17 must then be overcoated with Gilsonite Aluminium or Duromastic AC roof coatings.
Weathering of Asbestos cement sheet roofing is now becoming very evident due to age and sulpur dioxide pollution. This weathering is causing eosion of the cement binding matrix, leaving a loose mat of Cement and Asbestos fibres on the roof surface. This then allows loose fibres to escape in to the air and the black lichen growth sets in. As well as being a health hazard to the environment, the blackened, mossy roof is very unsightly. The Duromastic M17 system binds the surface of the sheet and also contains a highly effective fungicide to help inhibit future moss growth. This system also causes a significant reduction in roof weight during rain and helps provide a dryer interior environment.