Fosroc Renderoc® S 25kg

High Performance Concrete Reinstatement Mortar

Fosroc Renderoc S is a high-performance, polymer modified concrete repair mortar developed for the reinstatement and structural repair of reinforced concrete. Conforming to BS EN 1504-3 Class R4 requirements, it provides excellent compressive strength, high abrasion resistance and exceptionally low permeability to water, carbon dioxide and chlorides. It is specifically designed for both large-area concrete repairs and localised patch repairs where durability and long-term protection are critical.

Supplied as a one-component, pre-blended cementitious repair mortar, Renderoc S requires only the addition of clean water on site. The advanced shrinkage compensation system ensures long-term dimensional stability, while the polymer-modified formulation provides excellent protection against reinforcement corrosion and environmental attack. It can be applied by hand or wet spray techniques, making it suitable for a wide range of repair projects.

Key Features & Benefits

• BS EN 1504-3 Class R4 repair mortar
• Polymer modified cementitious repair mortar
• High compressive strength
• High abrasion resistance
• Extremely low permeability
• Excellent protection against chloride ingress
• High resistance to carbonation
• Shrinkage compensated formulation
• Long-term dimensional stability
• One-component system
• Just add water
• Suitable for hand application
• Suitable for wet spray application
• Contains no chloride admixtures
• Excellent compatibility with concrete strengths from 30–60 MPa
• Suitable for structural concrete repairs

Suitable Applications

• Reinforced concrete repairs
• Structural concrete reinstatement
• Concrete patch repairs
• Large-area concrete repairs
• Bridge repairs
• Car park repairs
• Concrete slab repairs
• Concrete wall repairs
• Beam repairs
• Column repairs
• Infrastructure refurbishment
• Industrial concrete repairs
• Marine concrete repairs
• Concrete protection projects
• Wet spray concrete repair applications

Technical Information

• Product Type: Polymer modified concrete repair mortar
• Classification: BS EN 1504-3 Class R4
• Application Method: Hand applied or wet spray
• Minimum Thickness: 5mm
• Vertical Application: Up to 10mm per layer (higher by spray application)
• Horizontal Application: Up to 100mm per layer
• Fresh Wet Density: Approx. 2150 kg/m³
• Fire Rating: Class A2 s1 d0 Non-Combustible
• Packaging: 25kg bags
• Coverage: Approx. 12 litres per 25kg bag (approximately 1.2m² at 10mm thickness)

Performance Data

Compressive Strength

• 1 Day: 20 MPa
• 28 Days: 55 MPa

Bond Strength

• Pull-Off Adhesion: 2.1 MPa

Elastic Modulus

• 37 GPa

Flexural Strength

• 13.8 MPa at 28 Days

Setting Time

• Initial Set: 3 Hours
• Final Set: 5 Hours

Frequently Asked Questions

What is Fosroc Renderoc S used for?

Renderoc S is used for structural and non-structural concrete repairs where high strength, abrasion resistance and low permeability are required.

Is Renderoc S suitable for large repair areas?

Yes. It has been specifically developed for both large-area concrete repairs and localised patch repairs.

Can Renderoc S be spray applied?

Yes. It can be applied using wet spray techniques for faster application and higher build thicknesses.

What compressive strength does it achieve?

Renderoc S achieves 55 MPa compressive strength at 28 days.

What thickness can it be applied at?

It can be hand applied from 5mm thickness, up to 10mm vertically and up to 100mm horizontally in a single application.

Is it suitable for trafficked areas?

Yes. Renderoc S is recommended for trafficked repair areas where other high-build repair mortars may not be suitable.

Downloads

Data Sheet