BITUMEN MASTIC is a trowel-applied, black, heavily-filled bituminous compound with added fibres for reinforcement. The product forms a surface skin, but the mass below remains soft to allow for moderate movement. Suitable for sealing and filling holes in mastic asphalt, roofing felt, corrugated iron, metal guttering and downpipes.
▪ Waterproofing, stopping, bedding, bonding and sealing.
▪ Adheres to/fills holes in: mastic asphalt, roofing felt,corrugated iron, cast iron, fibre cement, slates, lead,copper, zinc, concrete and timber.
▪ Fast drying
▪ Suitable for use with all bituminous surface coatings
▪ Remains flexible for long periods
As with all surface coatings, preparation of the surface is of great importance and will influence the degree of adhesion obtained and the life of the coating.
All surfaces must be sound, stable and thoroughly clean and dry. Metal surfaces should be wire brushed to remove rust. Where long term protection is re- quired an initial treatment of a rust-inhibitive product such as red lead or zinc phosphate should be used. Loose or blistered paint should be removed. New gal- vanised surfaces should be roughened with a wire brush or treated with a proprietary etch primer. If the surface is still dusty after preparation, or coated in weathered bitumen, prime with BLACK JACK® BITU- MEN PRIMER and allow to dry. To assist in cold weath- er application, store the material in a warm room overnight prior to use.
BITUMEN MASTIC is ready for use and should not be thinned. Apply by steel trowel or putty knife.
Force the compound into the crack, but finish with a 25mm band at a 3mm thickness running the length of the crack. For large cracks and holes, apply the compound over the area to be treated and embed a closely woven glass fibre membrane into the compound to overlap the crack or hole by 50mm. Allow to dry and then apply a second coat, fully covering the reinforcing membrane.
Tighten loose hook bolts and trowel around with mastic. Remove loose screws, re-bed screws and washers in BITUMEN MASTIC and tighten. Top seal in further mastic and to a smooth finish. If the sheet is cracked, clean and prime with BITUMEN/FLASHING PRIMER and apply a bandage strip of glass fibre em-bedded in the mastic. When dry, overcoat with BLACK