Everbuild Black Jack 903 Bitumen Trowel Mastic 1 Litre

DESCRIPTION

When a roof leak or crack appears, you need a sealant you can trust to stay watertight. The Everbuild Black Jack 903 Bitumen Trowel Mastic is a professional-grade, fibre-reinforced bituminous compound that goes on thick, grips fast, and stays flexible — making it one of the most reliable roof repair mastics available in the UK.

Unlike brush-on bitumen coatings, this trowel-grade mastic is heavily filled for direct application into cracks, voids, and joints. It sets with a firm surface skin whilst the compound beneath remains soft and resilient, allowing for the natural thermal movement that roofing structures experience throughout the year. The result is a durable, weatherproof seal that won't crack or peel under pressure.

BENEFITS

• Fibre-reinforced formula — added fibres give superior tensile strength across repaired areas
• Waterproof & weatherproof — forms an immediate seal against water ingress and weathering
• Flexible finish — remains pliable after curing to accommodate structural movement
• Excellent adhesion — bonds to felt, mastic asphalt, corrugated iron, cast iron, fibre cement, slates, lead, copper, zinc, concrete, and timber
• UV and temperature resistant — maintains integrity in year-round UK weather conditions
• Ready to use — no mixing or thinning required; apply straight from the tub with a steel trowel or putty knife
• Suitable for professionals and DIY enthusiasts — trowel-grade consistency makes it manageable for all skill levels

DIRECTIONS

Ensure the surface is clean and dry before application. Apply the trowel mastic with a suitable tool, spreading evenly. For best results, follow the instructions on the label and allow sufficient drying time.

WARNINGS

Keep out of reach of children. Use in a well-ventilated area. Follow safety instructions on the label.

Ideal for patching holes in flat roofs, sealing around roof fixings and flashing, repairing corrugated iron sheeting, and waterproofing gutters and downpipes. For large cracks, embed a glass fibre membrane into the first coat and apply a second coat once dry for a fully reinforced repair.