Flash Harry Charcoal Liquid Plastic WP/Sealer 5L

The Flash Harry Liquid Plastic Waterproofing & Sealer 5L Charcoal is a flexible acrylic waterproofing and coating solution designed for roofs, walls, parapets, and a variety of roofing details. Supplied in a 5-litre container with a charcoal finish, it is suitable for waterproofing repairs, renovations, roof maintenance, and protective exterior coating applications.

Flash Harry describes Liquid Plastic as a pure acrylic waterproofing polymer modified with latex, formulated to provide flexibility, UV stability, and adhesion. The product offers up to 350% stretch, helping the waterproofing system accommodate normal surface movement.

Flash Harry Liquid Plastic 5L Charcoal

Liquid Plastic is designed for waterproofing and coating compatible pitched and flat roofs, roofing details, and parapet walls.

According to the manufacturer, suitable applications include:

• Pitched roofs
• Flat roofs
• Flashings
• Lap joints
• Roof ridges
• Valleys
• Skylights
• Chimneys
• Roof screws
• Parapet walls
• General waterproofing repairs

The charcoal colour provides a practical dark finish that works particularly well with compatible dark roofing materials and exterior surfaces.

Flexible Waterproofing Protection

One of the main advantages of Flash Harry Liquid Plastic is its flexibility. The latex-modified acrylic formulation provides approximately 350% stretch, along with UV stability and adhesion.

For waterproofing applications, the manufacturer specifies that Liquid Plastic should be used with a waterproofing membrane. Proper saturation of the membrane during the first coat is critical to the performance of the complete waterproofing system.

Key Features

• Brand: Flash Harry
• Product: Liquid Plastic
• Size: 5L
• Colour: Charcoal
• Pure acrylic waterproofing polymer
• Latex-modified formulation
• Approximately 350% stretch
• Flexible waterproofing system
• UV stable
• Suitable for roofs and parapets
• Suitable for roofing details
• Water clean-up while wet
• Suitable for professional and DIY waterproofing projects

Surface Preparation

Correct surface preparation is essential for effective waterproofing.

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

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

Application Guidelines

Liquid Plastic can be applied using a brush, roller, or spray, depending on the application. The manufacturer’s technical data indicates a touch-dry time of approximately 1 hour at 25°C, with a second coat after approximately 4–6 hours under specified conditions. Full cure is approximately 7 days.

For waterproofing applications, ensure the membrane is properly embedded and saturated with the first coat rather than simply applying multiple coats over an inadequately saturated membrane.

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 this product for under-tile applications, swimming pools, or fibreglass structures.

Always follow the latest Flash Harry technical data sheet and product instructions for the specific waterproofing application.

Availability

Available in-store and online at Build It DTM.