Achieving a sand/cement screed or render that holds its ground, resists moisture, and handles thermal shifts can be challenging. ARDEX Abacrete is a liquid polymer additive that directly addresses these site realities. It enhances your mixes, ensuring superior bond strength and improved water resistance. The result is a resilient finish that accommodates thermal movement without cracking or delamination, bringing confidence to your project's foundation.
Traditional sand/cement screeds and renders often fall short when subjected to thermal expansion, contraction, or consistent moisture exposure, leading to bond failures and costly rework. ARDEX Abacrete is formulated as a liquid polymer additive to overcome these inherent limitations. It integrates directly into site-mixed sand/cement formulas, fundamentally modifying the screed or render itself, unlike standalone bonding agents that merely adhere materials together. This enhancement greatly improves shear and tensile bond strength, boosts water resistance, and allows the finished surface to accommodate thermal movement. It ensures your screeds and renders provide a durable base, whether for internal or external, commercial or residential projects on floors and walls.
ARDEX Abacrete significantly uplifts the mechanical performance of your cementitious mixes. When used in screeds, it helps achieve approximately 15 MPa compressive strength and 5 MPa flexural strength after 28 days. For renders, expect around 10 MPa compressive and 5 MPa flexural strength. These values translate to enhanced durability and resistance to cracking, critical for longevity in high-traffic or exposed areas. The 1-hour pot life offers sufficient working time for mixing and application on site.
Using ARDEX Abacrete involves precise mixing with your sand and cement. For a bonding slurry coat, combine 3 parts cement to 2 parts undiluted ARDEX Abacrete by volume. This slurry is applied up to 2mm thick using a roller, brush, or trowel, with your screed or render applied while the slurry is still wet. For screeds and renders, dilute ARDEX Abacrete with water at a 1:3 ratio by volume. Then, for a screed mix, combine 21 litres of this diluted solution with 40kg of Portland cement and 120kg of clean sand. For render, use 27 litres of diluted solution with the same cement and sand quantities. Tools clean up easily with water immediately after use, preventing hardened residue.
ARDEX Abacrete is typically introduced at the initial stages of a cementitious build-up. Its primary role is to enhance the physical properties of the screed or render mix itself. It forms a crucial interface when used as a bonding slurry coat, applied directly to the prepared substrate before the main screed or render is laid. This ensures a strong, monolithic bond. If a substrate is prone to rising damp, first apply a damp-proofing treatment like ARDEX WPM 300, then follow with an ARDEX Abacrete/cement slurry coat before applying your screed or render. This layered approach addresses both moisture ingress and mechanical performance.
Yes, ARDEX Abacrete is suitable for external applications when mixed into screeds and renders. Ensure the work area is protected from extreme weather during and after application to allow proper curing.
The recommended minimum thickness for an ARDEX Abacrete screed is 15mm. For thicknesses greater than 40mm, a reinforcing mesh is required; lay it between two layers of screed, not directly on the substrate.
It significantly improves shear and tensile bond strength, water resistance, and flexibility to accommodate thermal movement. This results in more durable screeds and renders with enhanced adhesion, preventing common failures.
Yes, ARDEX Abacrete is compatible with underfloor heating. For heated concrete slabs, apply ARDEX Abacrete undiluted in the slurry coat to ensure proper bond and performance.
| Application | Key benefit | Primary trades |
|---|---|---|
| Enhanced floor screeds (internal/external) | Significantly improves shear and tensile bond strength, reducing risk of debonding. Accommodates thermal movement, crucial for underfloor heating. Achieves approx. 15 MPa compressive strength for screed. | Tilers, Concreters, Builders |
| High-performance wall renders (internal/external) | Increases render adhesion and water resistance, preventing cracking and moisture ingress. Achieves approx. 10 MPa compressive strength for render. | Renderers, Plasterers, Builders |
| Slurry coat for bonding new to old cementitious substrates | Provides a robust bond layer for fresh screeds or renders over existing concrete, renders, or screeds, ensuring continuity and durability. Slurry coat achieves approx. 25 MPa compressive strength. | Tilers, Concreters, Waterproofers |
| Creating falls in wet areas (showers, bathrooms) | Supports durable, water-resistant screeds with specified falls (e.g., 1:60 in shower recesses), reducing water pooling and future moisture issues. | Waterproofers, Tilers |
Ensure all substrates are clean, sound, and properly prepared. Remove contaminants and roughen smooth surfaces to create a mechanical key.
Stir Planicrete SP thoroughly. Mix with cement and aggregates to required ratio. Add liquid first, then dry materials, and mix to a homogeneous consistency.
Apply slurry bond coat onto substrate just before placing mortar or screed. Keep the slurry wet at all times during application.
Apply modified mortar or screed while bond coat is still wet. Compact and finish using appropriate tools to ensure full contact.
Allow adequate curing time—typically 28 days or 1 week per cm thickness before tiling or further works.
Warning: Hazardous chemical.
Wear chemical protective gloves, safety glasses with side shields or chemical goggles, overalls, and a PVC apron. Safety footwear or gumboots are also recommended.
Use in a well-ventilated area. Local exhaust ventilation is usually required to prevent high concentrations of mist or vapours.
Store in original, securely sealed containers in a cool, dry, well-ventilated area, away from incompatible materials and foodstuffs. Protect from frost. Dispose of contents and containers to an authorised hazardous or special waste collection point in accordance with local regulations.
Proper substrate preparation is critical for achieving the specified bond and performance of ARDEX Abacrete-enhanced screeds and renders. Failure to prepare correctly can lead to debonding and system failure.
Surface prep: Ensure surfaces are clean, firm, and free from dust, dirt, oil, grease, curing compounds, release agents, and any other barrier materials. The substrate must be strong enough to support the intended load.
Primer: ARDEX Abacrete acts as a bonding agent applied as a slurry coat. If rising damp is present, treat the substrate first with ARDEX WPM 300 before applying the ARDEX Abacrete slurry.
Surface prep: Remove all loose material, dust, and contaminants. Ensure the surface is sound and capable of supporting the render.
Primer: Apply an ARDEX Abacrete slurry coat to enhance adhesion before rendering. Ensure the slurry is still wet when the render is applied.
Surface prep: Confirm the membrane is clean, fully cured, and compatible with cementitious overlays. Follow the membrane manufacturer's guidelines for overlay application.
Primer: Apply an ARDEX Abacrete slurry coat to ensure a strong bond between the membrane and the new screed or render.
| Property | Value |
|---|---|
| Colour | White liquid |
| Specific Gravity | Approx 1.01 g/ml |
| pH | 9-11 |
| Underfloor Heating Compatibility | Yes |
| Pot Life | 1 hour |
| Slurry Coat Compressive Strength 28 Days | Approx 25 MPa |
| Slurry Coat Flexural Strength 7 Days | Approx 7 MPa |
| Render Compressive Strength 28 Days | Approx 10 MPa |
| Render Flexural Strength 28 Days | Approx 5 MPa |
| Screed Compressive Strength 28 Days | Approx 15 MPa |
| Screed Flexural Strength 28 Days | Approx 5 MPa |
| Slurry Coat Mixing Ratio | 10L undiluted ARDEX Abacrete / 20kg cement (TDS) |
| Slurry Coat Mixing Ratio by Volume | 3:2 cement:ARDEX Abacrete (TDS) |
| Render Mixing Ratio | 27L diluted ARDEX Abacrete / 40kg cement / 120kg sand |
| Screed Mixing Ratio | 21L diluted ARDEX Abacrete / 40kg cement / 120kg sand |
| Dilution for Render/Screed | 1:3 ARDEX Abacrete to water by volume |
| Slurry Coat Application Thickness | Maximum 2mm |
| Screed Minimum Thickness | 15mm |
| Screed Reinforcing Mesh Required Above | 40mm |
| Render Recommended Thickness | 10mm |
| Render Maximum Single Coat Thickness | 13mm |
| Dry Time Mortar | Approx 24 hours (23°C, 50% RH) |
| Dry Time Screeds/Renders Before Tiling | At least 7 days |
| Coverage Slurry Coat | 100m² per 20L |
| Coverage Screed 15mm | 9m² per 20L |
| Coverage Self-Supporting Screed 40mm | 3m² per 20L |
| Coverage Render 10mm | 10m² per 20L |
| Packaging | 20L plastic pails |
| Shelf Life | 12 months (original unopened packaging, dry, 23°C, 50% RH) |
| Appearance SDS | Milky white liquid with a slight odour |
| Physical State SDS | Liquid |
| Relative Density (Water = 1) SDS | 0.99 - 1.012 |
| Initial Boiling Point and Range SDS | 100 °C |
| Vapour Pressure SDS | 2.33 kPa @ 20 °C |
| Solubility in Water SDS | Immiscible |
| Vapour Density (Air = 1) SDS | 0.62 |
| Volatile Component SDS | 80% vol |
| pH as a 1% Solution (dispersion) SDS | 9 - 11 |
Here are some common examples on where Mapei Planicrete SP used by our customers.
