Rust-Oleum Mathys Dacfill HZ Flat Roof Waterproofing 20kg Kit

Mathys Dacfill HZ is a quick-drying, water-based liquid membrane for horizontal roofs, supplied as a complete 20 kg kit (19.2 kg base with 0.8 kg activator).

Key features

• Quick drying, 100% watertight coating
• Resistant to UV radiation, acid rain, heat, frost and pollution
• Seamless elastic finish; abrasion resistant, rubber-like coat
• Non-flammable and self-extinguishing
• Suited to situations needing quick water resistance or recoatability

Where to use it

Waterproofing protection of flat roofs. Dacfill mesh must be used on every roof with a slope below 5%, where water may stand, or where substrate movement is expected. Do not apply on TPOs (thermoplastic olefins).

Technical details

• Mixing ratio base : activator 19.2 : 0.8 by weight (kit supplied matched); stir mechanically and use the same day; pot life 18 hours
• Two coats of 1–1.5 kg/m² each: first coat by roller to fix the Dacfill mesh (overlaps at least 5 cm), second coat by roller or airless once dry
• Touch dry and handle 1.5 hours; recoat 12 hours; fully cured 1 week (20°C)
• Brush, long-nap roller or airless (nozzle 18–23, 220 bar); do not dilute
• Apply in dry weather with some air movement or sun, above 5°C and below 85% humidity
• Matt finish; VOC 55 g/l; cleans up with water

Preparation

Clean and dry the substrate, free from flakes, gravel, dust and dirt. Fill joints with Elastofill and bridge active cracks with Dacfill bridging mesh. Prime porous concrete, hard PVC and polyester with Primer 44HS; very smooth concrete with Noxyde diluted 25% with water; iron and steel with undiluted Noxyde. Zinc, galvanised steel, copper, lead and aluminium can be coated after degreasing and light sanding.

Download the official Dacfill HZ technical data sheet (PDF). Read the safety data sheet and the pack label before use.