Sika Blackseal Lastic

Uses

Waterproofing for various applications such as:

• Flat roof waterproofing
• Waterproofing of water-retaining structures
• Flashing of roofs
• Gutters
• Parapet walls
• Sealing of fixings, lap joints and roof screws

Features & Benefits

• Applied with a brush, roller or trowel
• Supplied ready to use
• No primer needed
• Easily applied
• Non-sag on vertical surfaces
• Remains flexible at low temperature
• Crack-bridging
• Non-toxic

Application Instructions

Substrate Quality

• The substrate must be smooth, dry, and free of dust, oil or grease and loose or friable particles. Surface defects including blowholes, voids, honeycombing, etc., in the concrete, must be repaired with suitable Sika mortars before coating.

Substrate Preparation

• Rinse concrete surfaces with clean water. Clean contaminated substrates by suitable means including steam cleaning, high-pressure water jetting, etc.
• Concrete substrate: Prime substrates with one part Sika® Blackseal Lastic diluted by one part water.
• Metal surfaces: After degreasing the surface prime new galvanised surfaces with Sika® Blackseal Primer. Old surfaces affected by rust should be thoroughly cleaned and primed with a suitable metal etch primer.

Application Methods

• Manual application: Apply with a suitable brush or roller.
• First coat: Brush on a thick coat of Sika BlackSeal® Lastic onto the primed surface at a spread rate of 1,25m²/litre. Embed the membrane into the wet coat, ensuring that the bitumen impregnates the membrane and all air is expelled.
• Second coat: A second coat is applied once the first coat has dried sufficiently (approx. 3 hours), at a spread rate of 2,0m²/litre. The membrane must be well-saturated to ensure a good watertight barrier is formed.
• Final coat: A final coat should be applied once the second coat has dried. This coat should be applied at the rate of 1,25m²/litre to finish off the system. The completed waterproofing system should be left for approximately 2 weeks before filling a water-retaining structure with water. Ambient temperatures have an effect on the time period required for a full cure. If unsure please contact the Technical Department of Sika, before doing so.

Local Restrictions

• Please note that as a result of specific local regulations the performance of this product may vary from country to country. Please consult the local Product Data Sheet for the exact description of the application fields.

Storage Conditions

The product must be appropriately stored in original, unopened and undamaged sealed packaging in dry conditions at temperatures between +5 °C and +30 °C.

Higher storage temperatures may reduce the shelf life of the product.

Reference shall also be made to the storage recommendations within the safety data sheet.