Cemtop XD: High Performance Cementitious Flooring System

Product Overview

Cemtop XD is a polymer-modified cementitious screed product engineered as a thin-layer industrial wearing course flooring system. It is specifically designed for internal areas subjected to foot and forklift traffic, providing a durable and economical floor topping solution in industrial environments such as warehouses, light to medium engineering operations, food processing plants, and car parks.

Product Composition & Supply

Cemtop XD consists of a carefully formulated blend of selected cements and hard-wearing aggregates modified with polymers and flow agents. The product is supplied as a dry powder in two color formulations:

• Grey (Cemtop XD Grey)
• White (Cemtop XD White)

Both variants are supplied in 18-kilogram bags. The product requires only the addition of water for preparation, making application straightforward and eliminating the need for on-site batching, which ensures consistency of the mixed product.

Design Specifications

Minimum Requirements

• Minimum thickness: 6mm
• Maximum thickness: 12mm (single layer system)
• Concrete substrate strength: Minimum 25 MPa compressive strength OR surface tensile strength exceeding 1.25 MPa
• Concrete age: Minimum 14 days old
• Substrate preparation: Clean, sound, and well-prepared concrete free from loose material, oil, grease, and paint

Dual Layer Systems

For thicknesses exceeding 12mm, a dual-layer system is recommended using Cemtop GP Advanced or Cemtop GP as the underlayment material at a minimum thickness of 7mm, with a 6mm top layer of Cemtop XD applied over it.

Performance Properties

Cemtop XD demonstrates excellent mechanical and physical properties when fully cured at 28 days:

Property	Specification
Compressive Strength	>27 MPa @ 28 days
Flexural Strength	>7 MPa @ 28 days
Janka Hardness	12.7 MPa @ 28 days
Abrasion Index	7.6 @ 28 days (AS4456.9 standard)
Slip Resistance (Dry)	D1 (AS4586-2013)
Slip Resistance (Wet)	P4 (AS4586-2013)
Service Temperature	80°C
VOC Content	49 g/L

The abrasion index of 7.6 exceeds CMAA industrial pavement requirements (>7.0), demonstrating superior wear resistance suitable for heavy-traffic industrial applications.

Application Properties

Property	Specification
Foot Traffic Readiness	2 hours @ 25°C; 4 hours @ 10°C
Light Vehicle Traffic Readiness	24 hours @ 25°C; 36 hours @ 10°C
Full Cure Time	28 days
Mixing Ratio (Hand Application)	3.1-3.4 litres water per 18kg bag
Coverage	10.6 litres per 18kg bag at 6mm thickness covers approximately 1.75m²

Application Methods

Installation by Pump

Preferred method of application using a continuous mixer pump, which must be operated by an experienced contractor trained in the product and equipment use.

Installation by Hand (Single Layer System - up to 12mm)

1. Thoroughly prepare the floor surface
2. Prime with Nitoprime 330 diluted 1:4 (primer to clean water by volume); allow to dry (~45 minutes @ 23°C)
3. Apply second coat of Nitoprime 330 diluted 1:4; allow to dry (~90 minutes @ 23°C)
4. Apply Cemtop XD to required thickness onto the dry, primed surface
5. For final smooth finish, spike roll using the Cemtop spike roller

Installation by Hand (Dual Layer System - over 12mm)

1. Prepare and prime floor surface as above
2. Apply Cemtop GP Advanced underlayment to required thickness
3. When hardened, prime underlayment with Nitoprime 330 diluted 1:4; allow to dry
4. Apply 6mm Cemtop XD top layer to the primed underlayment

Primer System

Nitoprime 330 is the recommended primer for Cemtop XD applications. This water-based styrene-acrylate copolymer emulsion:

• Seals the substrate to prevent air release and pinhole formation
• Promotes adhesion between substrate and Cemtop XD
• Prevents desiccation of the cementitious material
• Achieves excellent water resistance after film formation
• Coverage: 6-8 m²/litre per coat (after dilution)

Two coats of primer are typically recommended to ensure complete substrate sealing.

Chemical Resistance & Protection

When cured, Cemtop XD demonstrates good resistance to water and oils. However, for areas subject to:

• Continuous water exposure
• Chemical attack from organic solvents
• Attack from organic or inorganic acids

Protective overcoatings using the Nitoflor range of resin-based floor coatings are recommended. Nitoflor FC130 is specifically recommended as a protective topcoat, requiring two coats applied within 3-6 hours of Cemtop XD installation.

Incompatibilities

Important: Cemtop XD is incompatible with Nitoflor PA application. Nitoflor PA should not be applied to polymer-modified cementitious screeds such as Cemtop XD.

Moisture & Environmental Requirements

• Concrete moisture content: Must be sufficiently dry to allow primer absorption
• For overcoating with impermeable toppings: Relative humidity of concrete floor must not exceed 75%
• Application temperature: Minimum 10°C during application
• Freeze protection: Required for 48 hours after placement
• Temperature precautions: For temperatures exceeding 25°C during application, contact Fosroc for advice
• Environmental protection: Protect from direct sunlight and drying winds during application and initial curing period

Safety & Classification

Cemtop XD is classified as not hazardous for Respirable Crystalline Silica (RCS) in accordance with the Australian Inventory of Industrial Chemicals, containing <0.1% RCS.

Product Shelf Life & Storage

• Shelf life: 2 years from date of manufacture when kept in original, unopened bags
• Storage conditions: If stored at high temperatures and/or high humidity, shelf life may be reduced
• Product condition: Do not use if lumps are present or loss of workability is experienced

Coverage Data

Product	Coverage
Cemtop XD	10.6 litres per 18kg bag yields ~1.75m² at 6mm thickness
Nitoprime 330	6-8 m²/litre per coat

Note: An additional 10% allowance is recommended for irregularities in floor surface and wastage.

Cleaning & Maintenance

• Fresh material: Remove from tools and equipment immediately with clean water
• Hardened material: Can only be removed mechanically
• Uncoated surfaces: May be cleaned with rotary scrubbing machines
• Avoid: Strong acidic or alkaline-based cleaning agents
• Coated surfaces: Follow maintenance recommendations from the relevant Nitoflor product data sheet

Key Advantages

• Very fast application and rapid cure, minimizing factory downtime
• Cost-effective compared to equivalent resin-based systems
• Dimensionally stable for large jointless areas
• Self-smoothing with minimal finishing required
• Durable smooth dense surface resistant to forklift truck traffic
• One-pack product applied by pump, eliminating on-site batching
• RCS Hazard Free classification

References

• [1] Fosroc_Cemtop_XD_TDS.pdf
• [4] Fosroc_Nitoflor_PA_TDS.pdf
• [11] Fosroc_Nitoprime_330_TDS.pdf