ARDEX A 70 GYPFLO – Quick Drying Flowable Calcium Sulphate Screed
Ready to receive floorcoverings in as little as 14 days – a high-performance, pre-blended, flowable screed designed for fast-track construction and excellent finish quality.
ARDEX A 70 GYPFLO is a quick drying, flowable calcium sulphate screed that combines high strength, superior workability, and fast drying properties. Pre-blended for consistency and convenience, it only requires the addition of water on site, ensuring accurate and reliable performance every time. With exceptional flow characteristics, ARDEX A 70 GYPFLO can be hand-applied or pump-applied, making it ideal for both large commercial projects and smaller installations with restricted access.
Key Features
- Walkable in as little as 6 hours at 20°C.
- Ready to receive floorcoverings in just 14 days (≤2% moisture content).
- Pre-blended for consistency and convenience – just add water.
- Can be pump or hand applied – perfect for areas with limited access.
- Excellent flow properties for a smooth, even surface finish.
- Low shrinkage formulation minimises cracking and curling.
- High early and final strength development (CA-C40-F7 classification).
- Suitable for use with underfloor heating systems.
- Environmentally conscious formulation with low embodied carbon – 0.49 kg CO₂ eq/kg.
Product Description
ARDEX A 70 GYPFLO is a premium quick-drying calcium sulphate-based screed specifically engineered to receive floor finishes in as little as 14 days – twice as fast as traditional calcium sulphate screeds. It is a pre-blended formulation requiring only the addition of water, ensuring consistency and reducing on-site errors. Designed for both unbonded and floating screed applications in internal environments, ARDEX A 70 delivers a highly durable, low-shrinkage surface suitable for direct floorcovering installation.
With its excellent flow properties and ease of placement, ARDEX A 70 GYPFLO is ideal for both commercial and domestic flooring projects. It achieves high compressive and flexural strength, providing a stable substrate for a wide range of floor finishes, including resilient, textile, and timber coverings.
Applications
- Suitable for unbonded and floating screeds in internal locations.
- Ideal for fast-track installations requiring early trafficking and quick drying.
- Use over underfloor heating systems (minimum 25mm cover over pipes).
- Perfect for both domestic and commercial projects.
- Can be used for repairs to existing calcium sulphate screeds.
Thickness Guidelines
| Application Type | Minimum Thickness (Domestic) | Minimum Thickness (Commercial) |
| Floating Screed | 35mm | 45mm |
| Unbonded Screed | 30mm | 40mm |
Note: Minimum cover over underfloor heating elements should be 25mm.
Mixing
Each 25kg bag of ARDEX A 70 GYPFLO requires up to 5 litres of clean water. Use clean potable water only and add the powder to the water. The correct water dosage should be verified using the flow ring test (target flow: 280–320mm). Do not exceed the recommended water content.
ARDEX A 70 can be hand mixed using a paddle mixer or machine mixed and pumped for larger areas. The working time of the mixed screed is approximately 2 hours at 20°C. The fresh mortar must be placed and finished within this working period.
Application
- Ensure substrate temperatures are above 5°C before application.
- Mix and place ARDEX A 70 in a single layer to the required thickness and levels.
- Use a tamping bar to spread and level the screed, working across the full area in two passes—one deep and one shallow for finishing.
- Do not allow the product to freeze during application or curing.
- Once hardened (typically after 48 hours), sand the surface to remove any loose materials before applying floor coverings.
Drying and Hardening
- Walkable: approx. 6 hours at 20°C
- Partially Loadable: approx. 24 hours
- Ready for floorcoverings: typically 14 days (≤ 2% moisture content at 20°C)
Use with Underfloor Heating Systems
After laying over a hot water underfloor heating system, allow 3 days before heating. Gradually raise the water temperature to 20°C and maintain for 3 days. Then increase to the maximum floor temperature for another 4 days, avoiding draughts. Allow the screed to cool to room temperature (≥15°C) before laying any floor finishes.
Technical Data
| Working Time | Approx. 2 hours at 20°C |
| Compressive Strength (28 days) | ca. 40 N/mm² (CA-C40-F7) |
| Flexural Strength (28 days) | ca. 7 N/mm² (F7) |
| Tensile Adhesion Strength | > 1.5 N/mm² |
| Thermal Conductivity (λz) | 1.2 W/mK |
| Thermal Expansion | 0.01 mm/mK |
| Thermal Load Capacity | Up to 55°C |
| Embodied Carbon (A1–A3) | 0.49 kg CO₂ eq/kg |
| Coverage | Approx. 0.4 m² per 25kg bag at 35mm thickness |
| Packaging | 25kg paper sacks with polyethylene liner |
| Shelf Life | 12 months in unopened packaging |
Benefits
- Twice as fast drying as standard calcium sulphate screeds.
- Excellent flow for smooth, level finishes.
- Minimises cracking and curling due to low shrinkage.
- Compatible with underfloor heating systems.
- High strength and long-term durability.
- Environmentally friendly with reduced embodied carbon.
FAQs
What is ARDEX A 70 GYPFLO used for?
ARDEX A 70 GYPFLO is a high-performance calcium sulphate screed used to create smooth, level, and durable floor bases. It’s ideal for both commercial and domestic floors requiring quick drying and early strength development.
How soon can floor coverings be laid on ARDEX A 70 GYPFLO?
Under typical site conditions (20°C and good ventilation), floor coverings can be applied in as little as 14 days once a moisture content of ≤ 2% is achieved.
Is ARDEX A 70 suitable for underfloor heating?
Yes. ARDEX A 70 is suitable for use over underfloor heating systems, provided a minimum 25mm cover is maintained above the heating pipes.
What are the strength properties of ARDEX A 70 GYPFLO?
ARDEX A 70 achieves a compressive strength of approximately 40 N/mm² and a flexural strength of 7 N/mm² after 28 days.
How long before the screed can be walked on?
The screed is typically walkable within 6 hours and can take light loads after 24 hours at 20°C.
Can ARDEX A 70 be used externally?
No. ARDEX A 70 is suitable for internal applications only and must not be used in areas with prolonged exposure to moisture.
What is the embodied carbon value of ARDEX A 70?
The embodied carbon value (A1–A3 production stage as defined in BS EN 15804) is 0.49 kg CO₂ eq/kg, making it a sustainable choice for low-impact construction.
How should ARDEX A 70 be stored?
Store in unopened packaging, off the ground, in a cool, dry location protected from drafts and moisture. Shelf life is 12 months when stored correctly.
