Concrete remains one of the most widely used construction materials for commercial and industrial buildings. However, even this robust material is vulnerable to cracking over time due to shrinkage, foundation movement, water ingress, and general wear and tear. For commercial property owners, facilities managers, and contractors, concrete crack injection is a proven, cost-effective method for addressing both structural and non-structural cracking.
In this guide, we explore how crack injection works, the different materials used, and when it’s necessary. We also highlight how it fits within broader services such as concrete repairs in the UK and concrete repairs in London for businesses looking to maintain the safety and integrity of their buildings.
What Is Concrete Crack Injection?
Concrete crack injection is a specialised repair method that involves injecting liquid resin directly into a crack in the concrete. The resin then hardens and seals the crack completely, restoring strength, preventing further movement, and in many cases, waterproofing the structure.
It’s a reliable solution for a wide range of commercial applications, including:
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Office buildings and car parks
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Warehouses and logistics centres
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Basements and lift pits
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Bridge decks, tunnels, and retaining walls
Depending on the type of crack and the environment, technicians will select either epoxy or polyurethane resin to achieve the desired outcome.
Epoxy vs Polyurethane Injection: What’s the Difference?
Two main types of resin are used in injection systems, each with distinct properties and use cases:
1. Epoxy Injection (Structural Repair)
Epoxy is a high-strength, rigid resin used for structural crack repairs. Once injected, it bonds the sides of the crack together and restores the concrete’s load-bearing capacity. It’s ideal for vertical and horizontal cracks in walls, slabs, columns, and beams—especially where the structure must regain its original strength.
Epoxy is frequently specified in epoxy injection UK projects involving heavy-duty structures like multi-storey car parks or commercial foundations.
2. Polyurethane Injection (Waterproofing and Flexibility)
Polyurethane (PU) resin is more flexible and expands upon curing. It’s best used for non-structural cracks, particularly where water ingress is present. As PU expands, it fills voids and creates a watertight seal, making it a preferred solution for basements, below-ground structures, and retaining walls.
When Should You Use Crack Injection?
Not all cracks require immediate attention—but some do. Here are common signs you may need crack injection:
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Cracks wider than 0.2 mm or showing signs of movement
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Water leaks or damp spots in concrete walls or floors
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Rust stains indicating reinforcement corrosion
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Cracks running through structural elements such as beams or supports
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Cracking in areas previously repaired that has reappeared
A professional inspection can help determine whether crack injection or another form of concrete repair is required.
How Does the Crack Injection Process Work?
At Apolodor Ltd, we follow a systematic approach to crack injection, ensuring high-quality and long-lasting repairs:
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Inspection & Assessment
Our engineers assess the size, type, and location of the crack to determine the best injection material and method. -
Preparation
The crack is cleaned and injection ports are installed along its length. -
Surface Sealing
A surface epoxy paste is used to seal the crack externally, preventing leakage during the injection process. -
Injection
Using specialist equipment, epoxy or polyurethane resin is injected under pressure through the ports until the crack is fully filled. -
Finishing
Once cured, ports are removed and the surface is cleaned or refinished as necessary.
Benefits of Crack Injection for Commercial Properties
Concrete crack injection offers multiple advantages for property owners and managers:
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Structural Restoration: Especially with epoxy, the repaired area can match or exceed original strength.
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Waterproofing: Polyurethane systems block water ingress and prevent freeze-thaw damage.
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Non-invasive: No need to remove or replace concrete sections—reducing downtime and cost.
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Long-term Performance: Professionally applied injection systems last for years when properly maintained.
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Cost-effective: Avoids expensive slab or wall replacement.
These benefits make injection a key part of many concrete repairs in London and beyond, especially for ageing commercial infrastructure.
Crack Injection vs. Other Concrete Repairs
While injection is ideal for internal sealing and structural bonding, it’s often part of a broader repair strategy. Severe spalling, corrosion of reinforcement, or large-scale deterioration may require surface repairs, concrete patching, or reinforcement replacement.
That’s why it’s critical to partner with a contractor who can provide a full range of concrete repairs in the UK, not just surface-level fixes. At Apolodor Ltd, we assess every project to determine the best combination of techniques to suit the structure’s needs.
Ready to Repair Your Concrete? Contact Apolodor Ltd
If you manage a commercial property with cracked or leaking concrete, concrete crack injection could be the answer. Whether you’re dealing with structural cracks in a car park, water ingress in a basement, or deterioration in a load-bearing wall, Apolodor Ltd provides expert crack repair solutions across the UK.
Our team brings decades of experience and uses high-performance epoxy and polyurethane systems to ensure lasting results. We support property owners with comprehensive advice and fully tailored repair services.
Contact us today to book a site visit, request a quote, or speak to our technical team.
