Flash Harry White Liquid Plastic WP/Sealer 20L

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

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

Flash Harry Liquid Plastic 20L White

The 20L pack size is particularly useful for larger projects where substantial areas or multiple waterproofing details need to be treated.

The white finish provides a clean appearance suitable for compatible light-coloured roofs, walls, parapets, and other exterior building surfaces. Flash Harry’s technical information confirms that Liquid Plastic is available in white and in 20L containers.

Suitable for Waterproofing Applications

Flash Harry Liquid Plastic is designed for a variety of compatible roofing and waterproofing applications, including:

• Roofs
• Walls
• Parapet walls
• Flashings
• Roof joints
• Lap joints
• Roofing screws
• Roof ridges
• Valleys
• Skylight details
• Waterproofing repairs
• Exterior maintenance

For waterproofing applications, Liquid Plastic should be used in conjunction with a waterproofing membrane. Flash Harry specifically notes that correctly saturating the membrane with the first coat is critical to achieving the intended waterproofing result.

Flexible Acrylic Waterproofing

The latex-modified acrylic formulation provides the flexibility required for suitable exterior waterproofing applications.

Liquid Plastic can be applied by brush, roller, or spray, and the manufacturer lists a full cure time of approximately 7 days at 25°C and 65% relative humidity in its technical information.

Key Features

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

Surface Preparation

Correct preparation is essential for effective waterproofing. Ensure surfaces are dry, clean, sound, and free from dust, dirt, grime, loose coatings, and contaminants.

For porous surfaces, Flash Harry recommends either a suitable bonding liquid or a priming coat made from a 50% dilution of Liquid Plastic with water.

Application Guidelines

For waterproofing, apply a generous first coat and immediately embed the appropriate waterproofing membrane into the wet product. The membrane should be fully saturated and installed without bubbles or wrinkles.

Flash Harry recommends approximately 75mm overlaps where membrane sections meet. Further coats should completely cover the membrane weave to form the finished waterproofing system.

For coating applications, the manufacturer recommends a minimum of two coats applied at right angles to each other.

Important Information

Flash Harry advises that Liquid Plastic should not be used to overcoat bitumen waterproofing systems. Compatibility should also be confirmed before applying it over unknown existing coatings.

The manufacturer does not recommend Liquid Plastic for under-tile applications, swimming pools, or fibreglass structures.

Official Flash Harry Liquid Plastic product information

Availability

Available in-store and online at Build It DTM.