Preparation
All necessary repair work should be carried out prior to application of the coating and the prepared surface should be clean, sound and free of flaking or loose material, moss or fungal growth. Any water, oil or grease must be removed and the surface allowed to dry.
Due to the wide variation in roofing materials and conditions, the following are generalised recommendations only. Please contact the Polycote technical helpline if more specific guidance is required for your application.
Moss, lichen and fungal growth – remove by stiff broom or jet washing, then treat the area with Polycote Destroy IT to inhibit further growth – Please see the relevant data sheet.
Porous surfaces – Acraflex Rubber Grade should be applied to porous surfaces which have been primed using ARG Primer.
Non-porous surfaces – Shiny surfaces should be abraded to allow for better adhesion. Acraflex Rubber Grade should be applied to non-porous surfaces once they have been thoroughly cleaned and are completely dry.
Asphalt, bitumen and felt roofs – New asphalt and bitumen surfaces should be allowed to weather prior to application.
Metal surfaces – remove all loose and flaking rust and treat with Polycote Rustex – refer to relevant Data Sheet. New galvanised steel should be allowed to weather, or may be treated with a suitable primer – Please see the relevant Data Sheet.
Gaps, cracks, joints and holes – Acraflex Rubber Grade will fill or bridge hairline cracks. Wider cracks or joints should be raked clean, opened out and filled using Polycote Rooflex Sealant. Allow sealant to cure before embedding membrane and overcoating – see under ‘Application’ following.
Application
Having prepared and primed the surface, and making sure it is completely dry, apply a generous coat of Acraflex Rubber Grade by brush or roller.
Any filled cracks or joints that are subject to movement should be reinforced with Polycote Flexible Membrane.
The membrane should be cut to approximately 100mm wide strips of appropriate length and laid into the wet Acraflex Rubber Grade coating over the repair, stippling with a paintbrush to integrate the membrane into the wet coating.
After all necessary membranes are embedded, an overall coating may be applied by brush or roller.
One overall coat is normally sufficient. However, further coats may be applied if required, allowing drying intervals between coats.
Application Temperature
Acraflex Rubber Grade should be applied at a temperature between 2˚C and 35˚C. Relative air humidity 85% r.h. maximum. Do not apply to frozen or damp surfaces. Do not apply in hot direct sunlight or coating may skin.
