Sika SikaRep 40 HB
Sika SikaRep 40 HB
SikaRep 40 HB is a class 40 cementitious mortar reinforced with polymer fibre for concrete repairing and rendering works. It can be applied to overhead, horizontal or vertical concrete or mortar surfaces, with a single-layer thickness of up to 40 mm without shuttering. Factory preblended for consistent quality control.
Key Features
- Contains polymer fibre to improve mechanical properties
- Good workability, easy to apply
- High build characteristics — up to 40 mm without shuttering
- Factory preblended for on-site quality control
- Good adhesion
- Non-toxic
- Suitable for rendering
Applications
- Overhead, horizontal or vertical concrete or mortar surfaces
- Repairing damaged and spalled concrete caused by reinforcement corrosion
- General concrete repair and refurbishment work
- Rendering works
Why Choose SikaRep 40 HB?
- Fibre reinforced: Contains polymer fibre to enhance crack resistance and mechanical performance
- High build without shuttering: Single-layer thickness from 6 mm to 40 mm with no formwork required, saving time on site
- Multi-directional application: Can be applied to overhead, vertical and horizontal surfaces for versatile use
- Factory preblended: Just add water — consistent, reliable quality every time
- Repair and render: Suitable for both structural concrete repair and rendering, one product for multiple uses
Packaging
| Product | Size |
|---|---|
| SikaRep 40 HB | 25 kg bag |
Technical Data
| Property | Value |
|---|---|
| Chemical Base | Cement based powder |
| Appearance / Colour | Concrete grey |
| Density (freshly mixed mortar, wet) | ~2.00 kg/L |
| Compressive Strength (28 days) | > 40 N/mm² |
| Tensile Strength (7 days) | > 2.0 N/mm² |
| Tensile Adhesion Strength (7 days) | > 2.0 N/mm² |
| Mixing Ratio (Water : Powder by weight) | 1 : 5.88 (~4.25 L water per 25 kg bag) |
| Consumption | ~68 bags/m³ (depending on surface and method) |
| Layer Thickness | Min. 6 mm / Max. 40 mm |
| Pot Life | ~40 minutes |
| Shelf Life | 9 months from date of production |
Application Instructions
Substrate Preparation
- Concrete must be sound, clean and free from oils, grease or surface contaminants
- All loose materials and surface laitance must be removed by high-pressure water jet blasting or mechanical means
- Small area and spot repairs should be mechanically prepared by needle gunning, bush hammering or similar
- Feathered edges around repair areas should be squared off with an angle grinder and chiselled to a minimum depth of 10 mm
- Dampen the prepared substrate with clean water
Bonding Coat
SikaRep 40 HB should be applied over a bonding coat slurry. Mix 1 part of Sika Latex to 1 part of fresh Portland cement by weight (refer to each product data sheet).
Mixing
Pour approximately 4.25 litres of clean water into a suitable container. Slowly add all the powder while mixing continuously with a low-speed electric drill (max 500 rpm, approx. 1000 watt) for a minimum of 3 minutes until a smooth, lump-free consistency is achieved. Water can be adjusted +/-10% to suit the required consistency.
Concrete Repair Application
- While bonding coat is still tacky, pack the mortar well into the repair cavity using a placing technique (not rendering) to fill all voids and ensure thorough compaction
- Force the mortar against the edge of the repair and progressively work towards the centre
- For repairs in excess of 40 mm thick, apply in layers ensuring each previous layer is sufficiently hardened and well keyed
- If previous layers are over 48 hours old, scabble the surface and dampen; a bonding slurry of Sika Latex and Portland cement (1:1 by weight) may be used between layers
- Steel trowel the final layer if required for a smooth, tight finish
Rendering Application
Apply the render with a trowel. Press the mortar into the concrete surface and level to the required thickness. Wipe the surface with a sponge or float for a smooth finish.
Curing Treatment
Protect against direct sunlight and wind while hardening. Cover all exposed mortar with wet hessian, plastic sheeting or use Sika curing compound.
Important Notes
- Shelf life is only 9 months (not the typical 24 months) — check the production date
- Store in undamaged, unopened original sealed packaging in cool dry conditions; protect from direct sunlight and frost
- Clean tools with water while mortar is still fresh; hardened material can only be removed mechanically
- All technical data are based on laboratory tests; actual results may vary due to site conditions
FAQ
What is the maximum repair thickness per layer?
Single-layer thickness ranges from a minimum of 6 mm to a maximum of 40 mm, with no shuttering required. For repairs exceeding 40 mm, apply in multiple layers, allowing each layer to harden before applying the next. If a previous layer is over 48 hours old, scabble the surface, dampen it and apply a bonding slurry.
Is a bonding coat required?
Yes. A bonding coat slurry of Sika Latex mixed with fresh Portland cement at a 1:1 ratio by weight must be applied to the prepared substrate. Apply SikaRep 40 HB while the bonding coat is still tacky.
Can it be used for rendering?
Yes. SikaRep 40 HB is suitable for rendering. Apply with a trowel, press into the concrete surface, level to the required thickness and finish with a sponge or float.
How long is the pot life after mixing?
Approximately 40 minutes. Add about 4.25 litres of clean water per 25 kg bag and mix with a low-speed drill (max 500 rpm) for at least 3 minutes until smooth and lump-free.
