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After a CCTV inspection, it is crucial to act on the findings. First, understand the report and prioritise issues by urgency: urgent problems, those needing prompt attent…
Pipe Guide · GAL
Galvanised Steel
Galvanised steel was used for water supply and some waste lines in Brisbane’s pre-1960 timber homes. It rusts from the inside out, so restricted flow and rusty water are the tell-tale signs it is near the end.
Quick Facts
- Typical lifespan
- 50 years
- Common installation period
- Early–mid 1900s
- Typical diameter
- DN15–DN50 (water & some waste)
- Root resistance
- Corrosion resistance
- Relining suitability
- Limited
- Typical repair methods
- Full replacement in copper, PEX or PVC, Limited relining
- Failure risk
- Medium-High
Typical Lifespan
50 years
050 yrs100+ yrs
40–50 years; rusts internally
Where You’ll Find It
Pre-1960 timber homes
Old water-supply lines
Some early waste lines
Original galvanised downpipes
Where It's Used
- Old water-supply and some waste lines
- Pre-1960 homes
How It Fails
- Internal rust and scale restricting flow
- Pinhole leaks
- Thread corrosion
Warning Signs
- Brown or rusty water
- Dropping water pressure
- Slow waste drainage
Common Repair Methods
- Full replacement in copper, PEX or PVC
- Limited relining
Advantages
- Strong and impact-resistant
- Was inexpensive and widely available
Disadvantages
- Internal rust and scale choke the flow
- Pinhole leaks develop with age
- Generally too far gone to reline
Preventative Maintenance
- Plan replacement once flow or pressure drops
- Replace in copper, PEX or PVC
- Do not rely on descaling as a long-term fix
Did You Know?
Rusty or discoloured water on an old property is often the pipe itself corroding, not the water supply.
Galvanised pipe is usually replaced rather than relined because the rust has already thinned the wall.
Can Galvanised Steel be relined?
Limited. Relining installs a new pipe inside the old one without digging. Whether it suits your Galvanised Steel depends on the pipe’s diameter and condition — a CCTV inspection confirms it. Overall repairability: Poor (replace).
Learn about pipe reliningBrisbane Field Notes
Common in Brisbane's pre-1960 timber homes. Usually replaced rather than relined once flow is restricted.
Greenslopes, Coorparoo, Annerley and Woolloongabba and other pre-1960 timber-home suburbs.
What we usually find on CCTV: Rusty, scaled internal walls with a heavily restricted bore, thread corrosion at fittings, and early pinhole leaks.
Galvanised Steel Pipes — FAQs
What are galvanised steel pipes?
Galvanised steel pipes are steel pipes coated with a layer of zinc to help protect against corrosion. They were commonly used in older Australian homes for water supply and some stormwater drainage applications.
How long do galvanised steel pipes last?
Galvanised steel pipes typically last between 40 and 70 years, depending on soil conditions, water quality, moisture exposure and maintenance.
Where are galvanised steel pipes commonly found?
Galvanised steel pipes are most often found in older Brisbane homes, particularly in water supply systems, external drainage and some older stormwater installations.
What are the most common problems with galvanised steel pipes?
Common problems include internal rust, corrosion, reduced flow, leaks, pinhole failures, joint deterioration and blockages caused by rust scale build-up.
Do galvanised steel pipes rust from the inside?
Yes. As the protective zinc coating deteriorates, the steel beneath can corrode internally, restricting water flow and increasing the likelihood of leaks and failures.
Can galvanised steel pipes be repaired?
Localised repairs are possible in some situations, but ageing galvanised steel pipes are often replaced with modern materials such as copper, PEX or uPVC depending on the application.
How are galvanised steel pipes inspected?
CCTV drain inspections can assess galvanised drainage pipes, while water supply pipes are typically inspected using pressure testing, visual inspections and leak detection methods.
Can galvanised steel pipes be relined?
Pipe relining may be suitable for some galvanised drainage pipes if they remain structurally sound, although many deteriorated steel pipes are more effectively replaced.
How do I know if my property has galvanised steel pipes?
Homes built before the 1970s commonly contain galvanised steel pipework. Visible grey threaded pipes or a professional plumbing inspection can help identify the material.
Should galvanised steel pipes be replaced?
If galvanised steel pipes show significant corrosion, frequent leaks, low water pressure or repeated failures, replacement with modern pipe materials is generally the most reliable long-term solution.
Other Pipe Materials
Photo Gallery
Real photos, CCTV stills and repair images that illustrate the guide above.
Real Pipe Photo 2
Failure / Damage 1
Not Sure You Have Galvanised Steel?
Three ways to confirm it — no obligation.
