Concrete Crack Repair — Sydney
Concrete Crack Repair, Sydney
Residential • Strata • Commercial • Infrastructure
Not every concrete crack should be repaired the same way. RemedialCore assesses what caused the cracking, and whether it is moving, structural or allowing water ingress, before selecting the repair method.
The same visible crack can point to very different causes — some are cosmetic, some are structural, and some are still moving. That's why we assess before we treat.
Not All Cracks Are The Same
The same crack can have very different causes.
Cracking can come from shrinkage as concrete cures, ground movement, thermal expansion, structural overload, corrosion, or water pressure behind a wall. Some cracks are stable and cosmetic. Others are still moving, or point to a bigger issue. Before we recommend a repair, we work through the same four questions.
Is it moving?
Active cracks change width with temperature, load or season. Dormant cracks stay stable. This changes which repair will actually last.
Is it structural?
Some cracks are cosmetic. Others indicate a load-bearing element is under stress and needs proper engineering assessment.
Is it letting water in?
A crack below ground, in a wet area, or in a water-retaining structure may need a different treatment to a crack that's purely cosmetic.
What caused it?
Shrinkage, settlement, thermal movement, corrosion or overload each point to a different fix — sometimes to more than one.
Our Crack Assessment & Repair Process
We diagnose before we treat — every time.
The right repair depends on what's actually happening inside the crack, not just what it looks like on the surface. This is how we get there.
Inspect
We record the crack's location, width, pattern and depth, and check for related issues like spalling or rust staining nearby.
Determine the cause
Shrinkage, thermal movement, settlement, structural overload and corrosion each behave differently and call for a different response.
Check for movement
Where needed, we monitor the crack to establish whether it's dormant or still active before a repair method is selected.
Select the appropriate method
Chosen for that specific crack — not applied by default. See the possible methods below.
Repair & verify
The selected method is carried out and the result checked against what the crack actually needed.
Possible Repair Methods — Selected By Diagnosis, Not By Default
Repair Methods In Detail
Epoxy and polyurethane crack injection.
Crack injection fills a crack from within rather than sealing over it. Which resin is used depends on whether the crack is still moving and whether water is passing through it — which is why the diagnosis comes first.
Epoxy injection is used where a crack is dormant and the concrete needs to act as one piece again. The epoxy is injected under pressure so it penetrates through the depth of the crack and cures into a rigid bond, helping restore continuity across a suitable dormant structural crack. Because a cured epoxy joint will not flex, epoxy injection is only appropriate once movement has been ruled out.
Polyurethane injection is used where water is coming through the crack, or where the crack is still moving. The polyurethane resin reacts with water and expands to fill the void, and stays flexible after curing, so it can accommodate further movement without breaking the seal. It is the usual choice for leaking basement walls, lift pits, planter boxes and construction joints.
How the injection is carried out. Injection ports are installed along the crack at set spacings, the surface between them is sealed so the resin cannot escape, and the resin is then injected port by port under controlled pressure until the crack is full through its depth. Ports and surface sealant are removed afterwards and the surface is made good.
When injection is not the answer. Injecting a crack that is still moving, or one caused by corroding reinforcement, simply moves the problem along — the crack reopens beside the repair, or the corrosion continues behind it. In those cases the cause is dealt with first, whether that means structural strengthening, concrete repair or crack monitoring before any resin goes in.
Why RemedialCore
Backed by process, licensing and decades of hands-on industry experience.
Every repair follows the same diagnosis-first discipline — documented, licensed and insured from start to finish.
Correct diagnosis first. We identify what's causing the crack, and whether it's moving, before any repair method is chosen.
Decades of hands-on industry experience across hundreds of commercial, residential and infrastructure projects.
Fully licensed & insured — NSW Builder and Waterproofing licences, Public Liability, Home Owner Warranty and Professional Indemnity cover.
Engineering-aligned delivery where the repair scope requires engineering input or specification.
Clear communication with clients, consultants and project teams throughout the job.
Backed by CBS Builders — established in 2009, servicing Sydney.
Repair Systems We Use
Show Us The Problem
Send us photos of the cracking — we'll help identify what's happening.
Fill in the details and attach a few photos. We'll review what you send and advise you on the appropriate next step.
Call or email direct
Response time
We reply to every enquiry within one business day.
Service area
Sydney.
Different issue?
See all our services — concrete cancer, waterproofing, carbon fibre and corrosion protection.
We reply to every enquiry within one business day. If it's urgent, call us on 02 9502 2259.