Flash Harry Black Liquid Plastic WP/Sealer 20L

The Flash Harry Liquid Plastic Waterproofing & Sealer 20L Black is a flexible acrylic waterproofing solution designed for roofs, walls, parapets, flashings, and other compatible roofing applications. Supplied in a large 20-litre container with a black finish, it is ideal for larger waterproofing projects, roof maintenance, renovations, and exterior building repairs.

Flash Harry describes Liquid Plastic as a pure acrylic waterproofing polymer modified with latex, providing flexibility, UV stability, and adhesion. The manufacturer specifies approximately 350% stretch, helping the waterproofing system accommodate movement on suitable surfaces.

Flash Harry Liquid Plastic 20L Black

The 20L pack size is particularly suitable for larger waterproofing and maintenance projects where significant surface areas need to be treated.

The black finish makes it a practical choice for compatible dark-coloured roofs, flashings, parapets, and other exterior surfaces.

The 20L Black variant is an established size and colour option within the Flash Harry Liquid Plastic range.

Suitable for Waterproofing Applications

Flash Harry Liquid Plastic can be used for a range of compatible roofing and waterproofing details, including:

• Roofs
• Walls
• Parapet walls
• Flashings
• Lap joints
• Roofing screws
• Roof joints
• Waterproofing repairs
• Exterior maintenance
• Renovation projects

For waterproofing applications, Flash Harry specifies that Liquid Plastic should be used in conjunction with a waterproofing membrane, with correct saturation of the membrane during the first coat being particularly important.

Flexible Acrylic Waterproofing

The latex-modified acrylic formulation provides approximately 350% stretch, together with UV stability and adhesion. These characteristics make Liquid Plastic suitable for exterior waterproofing applications where flexibility is important.

For coating applications, the manufacturer’s technical information indicates approximate coverage of 3m² per litre per coat, depending on the surface.

Key Features

• Brand: Flash Harry
• Product: Liquid Plastic
• Size: 20L
• Colour: Black
• Pure acrylic waterproofing polymer
• Latex-modified formulation
• Approximately 350% stretch
• Flexible waterproofing protection
• UV stable
• Suitable for compatible roofs
• Suitable for walls and parapets
• Suitable for roofing details and repairs
• Water clean-up
• Large 20L size for bigger projects

Surface Preparation

Surfaces should be dry, clean, sound, and thoroughly free from dust, dirt, grime, loose coatings, and other contaminants before application.

On porous surfaces, Flash Harry recommends a priming coat consisting of a 50% Liquid Plastic and water dilution, or the use of a suitable bonding liquid.

Application Guidelines

For waterproofing applications, apply Liquid Plastic with the appropriate waterproofing membrane according to the manufacturer’s instructions. Proper saturation of the membrane is critical to forming the intended waterproofing system.

For coating applications, apply the required coats evenly and allow sufficient drying time between coats. Follow the manufacturer’s instructions regarding application rate, weather conditions, and curing.

Important Information

Flash Harry states that Liquid Plastic should not be used to overcoat existing bitumen waterproofing systems and compatibility should be checked when applying over unknown existing coatings.

The manufacturer’s technical guidance also states that the product is not recommended for under-tile applications or areas of permanent ponding, and it should not be applied when rain is imminent. Recommended surface application temperature is between 5°C and 35°C.

For complete technical guidance, refer to the official Flash Harry Liquid Plastic product information.

Availability

Available in-store and online at Build It DTM.