Everbuild Bitumen Trowel Mastic 5L - Black Jack 903

Sika® Black Jack®-903 Bitumen Trowel Mastic

Sika® Black Jack®-903 Bitumen Trowel Mastic is a black, heavily-filled, fibre-reinforced bituminous compound. Specifically designed for trowel application, it forms a surface skin while the mass below remains soft and plastic to allow for moderate movement. It is the ideal solution for waterproofing, stopping, bedding, bonding, and sealing gaps or holes in various roofing and building substrates.

Primary Uses

• Sealing & Filling: Perfect for filling holes and cracks in mastic asphalt, roofing felt, corrugated iron, cast iron, and fibre cement.
• Roof Repairs: Used for repairing leaks in gutters, downpipes, slates, lead, copper, and zinc.
• General Building: Suitable for bedding and bonding on concrete and timber surfaces.

Features & Advantages

• Fibre-Reinforced: Added fibres provide strength and durability for structural repairs.
• Long-Term Flexibility: Remains flexible for long periods after application, accommodating natural movement.
• Fast Drying: Develops a surface skin within approximately 24 hours.
• Excellent Adhesion: Bonds strongly to most common building materials.
• Chemical Resistance: Resistant to water, most salt solutions, and dilute acids or alkalis.

Technical Specifications

• Yield / Coverage: Approximately 0.5 m² per litre (at 2 mm wet thickness).
• Service Temperature: -10 °C to +50 °C.
• Application Temperature: +5 °C to +40 °C (surfaces must be free from ice and water).
• Drying Time: 24 hours to develop a surface skin; remains plastic beneath for many months.