RENO E742 STRUCTURE
BENEFITS
- Efficient regardless of the type of cracks
- The repair is final and solid
- No stapling of concrete
CHARACTERISTICS
- Color: Liquid clear + pale yellow
- Working time: 30 – 45 min
- Curing time: 24h
APPLICATION
Slowly add the hardener into resin (part A + B) while mixing, mix thoroughly for 3 minutes with an electric drill and mixing paddle. Apply the mixture immediately. Clean the crack, glue transparent injection ports on face of cracks every 30 to 50cm. Inject RENO E742 STRUCTURE (A+B) using a pressure pot or caulking gun. Start injecting from the bottom port at a low pressure; gradually bring the pressure up (from 200g to 5kg/cm² depending on the type of crack). When the resin starts coming out of the higher port which serves as an air hole; cap the lower port and move on to next, the higher part, until the whole crack is filled.
Substrate consolidation resin for weak surfaces
RENO E742 STRUCTURE acts as a substrate consolidation resin, designed to strengthen weak or friable screeds. When applied across a surface, it penetrates and consolidates the upper layer, improving cohesion and durability.
This makes it suitable as:
- A screed consolidation epoxy
- A surface consolidation epoxy
- A subfloor strengthening resin
It can also be used for case hardening surfaces that fail in-situ strength test
Concrete crack repair epoxy for joints and static cracks
As a concrete crack repair epoxy, RENO E742 STRUCTURE is specifically formulated for:
- Static cracks
- Construction joints
- Stress control joints
- Sawn shrinkage joints
It is suitable for cracks up to 1 mm without the need for opening, streamlining the repair process and reducing preparation time.
This makes it an efficient crack repair epoxy system for pre-treatment prior to levelling compounds.
Screed crack repair epoxy and subfloor preparation
This screed crack repair epoxy is widely used before the application of levelling compounds, ensuring a stable and prepared substrate. It is compatible with:
- Concrete
- Cement screeds
- Calcium sulphate screeds
- Underfloor heating systems
Its role as a pre-levelling crack repair system supports long-term flooring performance.
Application process: RENO E742 STRUCTURE
Quick Application Steps (On-Site Guide)
- Prepare: Ensure cracks/joints and substrate are clean, dry and dust-free
- Mix: Combine Part A (resin) with Part B (hardener) at 2:1 ratio
- Apply: Inject or pour into cracks/joints or spread for surface consolidation
- Finish: Broadcast with dry sand if required for adhesion
- Wait: Allow to cure fully (~24 hours) before further works
1. Subfloor preparation
Correct preparation is essential for resin performance:
- Substrate must be dry, sound and free from contaminants such as oil, grease and dust
- Remove laitance, weak surface layers and residues using mechanical preparation
- Vacuum thoroughly to ensure all loose material is removed
- Open cracks ≥1 mm to a minimum depth of 5 mm; smaller cracks can be treated directly
- Ensure joints are clean and free from friable material prior to filling
- Confirm suitability of structural cracks before repair
All surfaces must comply with site standards prior to application.
2. Mixing
- Add Part B (hardener) into Part A (resin) in a 2:1 ratio by volume
- Mix thoroughly for 2–3 minutes using a slow-speed drill (max. 300 rpm)
- Ensure a uniform blend while minimising air entrapment
- Working time: approximately 30–45 minutes
Important: Mixed material is exothermic—do not leave in bulk and apply immediately.
3. Application
- Apply immediately after mixing by pouring, injecting or spreading as required
- For cracks/joints: fill until fully saturated using cartridge or mixed resin
- For consolidation: distribute across the surface and allow penetration into the substrate
- Broadcast with dry quartz sand where required to enhance adhesion of subsequent layers
- Repeat filling if resin is absorbed into deep or porous cracks
- Remove excess sand after curing before applying further systems
Suitable for crack repair, joint filling and strengthening weak substrates.
4. Drying & curing
- Working time: ~30–45 minutes
- Full cure: ~24 hours
Protect from contamination and maintain stable conditions during curing.
5. Underfloor heating
- Switch off heating systems 48 hours before, during, and for at least 48 hours after application
- Gradually reintroduce heat once curing is complete
Common mistakes to avoid
- Incorrect mixing ratio (must be 2:1 Part A to Part B)
- Mixing at high speed, causing air entrapment
- Leaving mixed resin unused, leading to premature curing (exothermic reaction)
- Applying onto dusty or contaminated substrates
- Not opening wider cracks (>1 mm) prior to filling
- Skipping sand broadcasting where required for adhesion
- Applying outside recommended temperature range (+10°C to +25°C)
A complete epoxy resin for crack repair and consolidation
Combining the benefits of an epoxy resin for crack repair, concrete crack repair epoxy, and substrate consolidation resin, RENO E742 STRUCTURE provides a comprehensive solution for repairing cracks, stabilising joints, and strengthening subfloors prior to further flooring applications.
Frequently Asked Questions
Subfloor reinforcement is important because it strengthens and consolidates weak or non-cohesive substrates and provides a stable and durable base for floor installation. These solutions improve surface cohesion, integrity and load-bearing capacity and help prevent cracks and the risk of delamination.
Reinforcing a subfloor improves surface cohesion, integrity and load-bearing capacity, creating a stable and durable base for flooring installation. RENO U550 REINFORCE is described for strengthening and stabilizing weak subfloors, and RENO E742 STRUCTURE can consolidate weak upper layers of the substrate.
Reinforcement should be used when the substrate is weak or non-cohesive, or where weak upper layers need consolidation before flooring installation.
Simple patching will not last for crack repair. You'll need crack repair solutions that work in depth for cracks and construction joints, with precise filling and reliable reinforcement.
Crack repair systems are the solutions for repairing cracks and construction joints. They provide precise filling and reliable reinforcement. The Bostik products RENO P520 EASY and RENO E742 STRUCTURE are suitable for crack repair and joint filling.
The crack repair sequence includes preparing the substrate, cleaning and vacuuming the crack or joint, filling with resin, broadcasting dry quartz sand onto the wet resin, allowing the product to cure, removing excess sand, and then carrying out the subsequent primer or levelling stage as required. Opening the crack is only stated when crack width or repair conditions require it.
Static cracks in screeds should be repaired using a resin such as RENO P520 EASY or RENO E742 STRUCTURE, followed by sand broadcasting to ensure adhesion. If reinforcement is required, a fiberglass mesh such as RENO U720 or U736 CONNECT can be applied in combination with repair mortars.
Cracks and joints should be cleaned and prepared, then filled using resin systems. RENO E742 STRUCTURE is designed for repairing construction joints, shrinkage joints and cracks before levelling. RENO P520 EASY provides a fast-setting solution for non-structural cracks and joint sealing. For reinforcement, RENO U736 CONNECT can be embedded into repair mortar or resin to bridge cracks.
The substrate must be sound, dry, and clean. Static cracks should be repaired using a suitable resin system such as RENO P520 EASY or RENO E742 STRUCTURE. Depending on substrate type, priming may be required before applying levelling compounds or repair mortars.
Static cracks and joints can be repaired with resin systems such as RENO P520 EASY or RENO E742 STRUCTURE. RENO P520 EASY is for rapid repair of non-structural cracks and joint sealing, while RENO E742 STRUCTURE is for repairing cracks and filling joints in reinforced concrete and sand/cement screeds, and for consolidating weak upper layers. After filling, dry quartz sand is broadcast onto the wet resin to improve bonding before subsequent levelling or adhesive application.
Subfloors must be clean, dry, sound and free from contaminants such as dust, grease or old adhesive residues before application. Mechanical preparation such as grinding, brushing or vacuuming is required. After preparation, cracks should be repaired using resin systems like RENO P520 EASY or RENO E742 STRUCTURE, followed by smoothing or levelling using suitable repair mortars.
Cracks are repaired by filling them with resin after proper preparation. Clean and open cracks if required, fill with resin such as RENO P520 EASY or RENO E742 STRUCTURE, then sprinkle quartz sand onto the wet resin to improve adhesion of subsequent layers.
RENO P520 EASY is a solvent-free 2-component silicate resin for rapid repair of non-structural cracks and joint sealing, with a walk-on time of about 30 minutes and a curing time of about 45 minutes. RENO E742 STRUCTURE is a 2-component solvent-free epoxy for repairing cracks and filling joints in reinforced concrete and sand/cement screeds, and it can also be used to consolidate weak upper layers of the substrate, with a curing time of about 24 hours. RENO P520 EASY is the faster setting option, while RENO E742 STRUCTURE also covers substrate consolidation.
Drying time depends on the product used. RENO P520 EASY is walkable after about 30 minutes and cures in about 45 minutes. RENO E742 STRUCTURE cures in about 24 hours. RENO C950 QUICK is walkable after about 45 minutes, with floor covering possible within hours depending on the finish.
Weak or unstable subfloors can be strengthened using reinforcement systems combined with resin or mortar. RENO U550 REINFORCE is designed to stabilise weak substrates and distribute pressure. RENO E742 STRUCTURE can also be used to consolidate weak screeds by penetrating and strengthening the substrate surface.
Subfloors can be stabilised by combining repair mortars with reinforcement systems. RENO U550 REINFORCE distributes loads and stabilises weak substrates, while epoxy resins like RENO E742 STRUCTURE improve the strength of the surface before applying flooring systems.
