Crosflow 820 Bulk Filler – 20kg Bag is a cementitious, non-structural floor underlayment designed for internal bulk fill and levelling applications. With excellent adhesion properties and versatile application thickness (from 5mm to 80mm), it’s ideal for creating falls, ramps, and floor grades on both new and existing concrete floors prior to installing floor coverings.

Specifications & Features

• Type: Cementitious bulk filler underlayment
• Application Thickness: 5mm to 80mm in a single pour
• Set Time: Initial set in 2 hours at 23°C
• Ready for Floor Coverings: 4 hours for carpet & tiles, 24 hours for vinyl & timber
• Coverage:
  • Approx. 1.1m² at 10mm thickness (leveller consistency)
  • Approx. 1.0m² at 10mm thickness (screed consistency)
• Water Temperature Range: 15–25°C for optimal mixing

Applications

• Bulk filling of uneven concrete floors
• Creating ramps, falls and screed gradients
• Underlayment prior to applying:
  • Carpet, carpet tiles, ceramic tiles (after 4 hrs)
  • Vinyl or timber (after 24 hrs)
• Internal flooring in residential and commercial projects
• Suitable for both new builds and refurbishment works

Installation Tips / Usage Guidelines

• Levelling: Pour mixed Crosflow 820 onto the prepared surface and spread using a gauged spreader. Product self-levels within 10–15 minutes.
• Screeding: For thicker applications or creating falls, spread using a screed bar or power screed. Can be poured up to 80mm thick in a single application.
• Ensure a wet edge for seamless blending if pouring in stages.
• Wear spiked footwear to avoid indenting while product is fluid.
• Allow appropriate curing time before applying floor coverings based on the type of material.

Delivery & Pickup

• Sydney-wide delivery
• Crane trucks with up to 21m reach available to get your delivery to you exactly where you need it
• Click & Collect available – ready in 2 hours
• Bulk pricing available for account customers

Need Help?

Call us on (02) 8543 3401. We can help you with quantity calculations, product information, and delivery solutions.