Flash Harry Charcoal Liquid Plastic WP/Sealer 20L

The Flash Harry Liquid Plastic Waterproofing & Sealer 20L Charcoal 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 charcoal finish, it is ideal for larger waterproofing projects, renovations, roof maintenance, 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 states that the product offers approximately 350% stretch, helping it accommodate movement in suitable waterproofing applications.

Flash Harry Liquid Plastic 20L Charcoal

The 20L pack size provides a practical option for larger waterproofing jobs where substantial areas or multiple roof details need to be treated.

The charcoal colour provides a dark, modern finish suitable for compatible roofing materials, parapets, walls, and other exterior surfaces. Flash Harry’s technical information confirms that Liquid Plastic is available in charcoal and in 20L pack sizes.

Suitable for Waterproofing Applications

Flash Harry Liquid Plastic is designed for waterproofing applications on compatible building surfaces. Typical applications include:

• Roofs
• Walls
• Parapet walls
• Flashings
• Lap joints
• Roof ridges and valleys
• Roofing screws
• Skylight details
• Waterproofing repairs
• Exterior maintenance
• Renovation projects

For waterproofing applications, Flash Harry states that Liquid Plastic should be used in conjunction with a waterproofing membrane. The first saturation coat is particularly important to the performance of the completed system.

Flexible Acrylic Waterproofing

The latex-modified acrylic formulation provides 350% stretch, along with UV stability and adhesion. These properties make Liquid Plastic suitable for exterior areas where a flexible waterproofing system is required.

The product can be applied by brush, roller, or spray, depending on the application. The technical data lists touch-dry time at approximately 1 hour at 25°C, with a second coat after approximately 4–6 hours under specified conditions.

Key Features

• Brand: Flash Harry
• Product: Liquid Plastic
• Size: 20L
• Colour: Charcoal
• 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

Ensure surfaces are dry, clean, sound, and free from dust, dirt, grime, loose material, and contaminants that could interfere with adhesion.

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

Application Guidelines

For waterproofing applications, apply Liquid Plastic together with an appropriate waterproofing membrane. The membrane should be properly embedded and saturated during the first coat.

Applying multiple coats over a membrane that was not properly saturated initially will not provide the intended result, according to Flash Harry.

Allow sufficient drying time between coats and follow the manufacturer’s instructions regarding application rate, weather conditions, surface preparation, and curing.

Important Information

Flash Harry advises that Liquid Plastic should not be used to overcoat bitumen waterproofing systems. Compatibility should also be confirmed when applying the product 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.