“How much will the concrete cancer repairs cost?” is usually the first question a strata committee asks after someone finds rust stains or a piece of concrete on a balcony. The honest answer is that nobody can give a reliable figure until the damage is mapped, because the cost is driven by how many repairs there are, how deep they go and how hard they are to reach. This guide explains what drives the price in Sydney and how to get quotes you can actually compare.
The short answer
Concrete cancer repair costs depend on four things: the number of repair sites, the depth and size of each repair, the access method and whether the water source is fixed at the same time. On multi-storey buildings, access is often the largest single cost, which is why repairing scattered defects by rope access can cost far less than scaffolding the whole façade. The way to control the cost is to inspect and map the damage first, then price the work from a schedule of rates.
What drives the cost of concrete cancer repairs
1. Number of repair sites
Concrete cancer rarely appears in one place. It shows up as patches along balcony slab edges, window heads, columns and parapets. Ten small repairs spread over eight storeys cost more to reach than one larger repair at ground level.
2. Size and depth of each repair
A shallow repair where the steel is only lightly corroded is quick. A deep repair, where concrete has to be broken out behind the reinforcement and the bar is badly corroded or needs supplementing, takes longer, uses more material and may need an engineer’s input.
3. Access
Scaffolding, a boom lift, a swing stage or rope access each have very different set-up costs. When defects are scattered across a tall façade, rope access lets technicians reach each patch directly without paying to scaffold areas that need no work. Where repairs are concentrated, very large or need heavy materials at height, scaffolding can be the better option.
4. Engineering and specification
Larger or structural repairs should be specified by a structural or remedial engineer. That adds a fee, but it also gives every contractor the same scope to price, which makes quotes comparable.
5. Fixing the water source
Repairs that do not deal with the water that caused the corrosion often fail again. Budget for sealant replacement, crack repairs, drainage fixes and a protective coating in the same access program.
6. Finishing and painting
Repaired areas need to be coated so they blend in and resist water. If the façade is due for a repaint anyway, combining repairs and painting on one access set-up usually saves a second mobilisation.
7. Site conditions
Work over footpaths, entries and car parks needs exclusion zones and sometimes council approval. Roof access, lift use and permitted working hours also affect the program.
Why early repairs cost less
Corrosion does not stop on its own. Each year water keeps reaching the steel, the area of damaged concrete grows and more of the repair becomes deep repair. On a tall building there is also the safety risk of falling concrete. Repairing a handful of small defects now is almost always cheaper than repairing a larger number of deep ones in five years.
How to get quotes you can compare
- Start with a mapped inspection. Each defect photographed, sounded for hollow areas and located on an elevation. Our building condition inspections are done on ropes, so defects at height are seen up close.
- Ask for a schedule of rates. A price per repair by size and depth, plus the access and set-up cost, lets you compare contractors on the same basis and control cost when more defects are found once work starts.
- Set provisional quantities. Agree an estimated number of repairs of each size, so the committee can approve a budget with a clear process for variations.
- Check the repair method. Break-out behind the steel, steel treatment, repair mortar and protective coating should all be stated. “Patch and paint” is not a concrete cancer repair.
- Check what is excluded. Engineering, council permits, painting of whole elevations and water source repairs are common exclusions.
Rope access or scaffolding for concrete repairs?
| Situation | Usually better value |
|---|---|
| Scattered repairs across several storeys | Rope access |
| Repairs plus sealant and painting on the same façade | Rope access, with one set-up for all of the work |
| Heavy structural work concentrated on one area | Scaffolding or a work platform |
| Low-rise building with good ground access | Often a boom lift or ladders |
A good contractor will say which method suits your building at inspection rather than push one method onto every job.
FAQs
How much does concrete cancer repair cost in Sydney?
It depends on the number, size and depth of the repairs and the access needed. A mapped inspection and a schedule of rates is the most reliable way to price it and to compare contractors.
Is concrete cancer covered by building insurance?
Generally not, because it is a gradual deterioration and maintenance issue rather than sudden damage. Check your own policy with your broker.
Who pays for concrete cancer repairs in a strata building?
Repairs to common property, which usually includes the external walls and balcony slabs, are generally the owners corporation’s responsibility and are often funded from the capital works fund. Check your strata plan and by-laws.
Why do some quotes vary so much?
Different assumptions about the number and depth of repairs, the access method and what is excluded. Pricing from the same mapped scope and a schedule of rates removes most of the difference.
Can repairs be done without scaffolding?
Often yes. Rope access technicians can break out, treat the steel, reinstate and coat repairs at height on many Sydney buildings.
Found rust stains, cracks or loose concrete? Ace Abseiling inspects and repairs concrete cancer on strata and commercial buildings across Sydney using rope access, and can seal and paint in the same program. Read more about the signs and causes of concrete cancer, or send us photos for an inspection and quote. Call 1300 926 176.
