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    Old Galvanised Pipes: Why They Fail and When to Re-Pipe Your Home

    Many older Johannesburg homes still have galvanised steel pipes that rust from the inside. The signs they're failing, why patching doesn't work, and what re-piping involves.

    31 March 2026 6 min read
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    If your older Johannesburg home has weak, worsening water pressure and brown water in the mornings, the culprit may be hidden in the walls: galvanised steel pipes quietly rusting themselves shut. Here's what's happening and when to act.

    Why galvanised pipes fail

    Galvanised steel corrodes from the inside out. Over decades, rust and scale build up, narrowing the bore — which strangles pressure and flow — and eventually causing leaks and discoloured water. Once internal corrosion sets in, it only gets worse.

    The signs

    • Water pressure that has slowly worsened over years
    • Brown or discoloured water, worst first thing in the morning
    • Recurring leaks
    • Visible rust or weeping on exposed pipes

    Why patching doesn't last

    Patching one failed section of a corroded galvanised system just buys time — the next weak spot fails soon after, because the whole network is degrading. If corrosion is widespread, repair after repair becomes false economy.

    Re-piping: the lasting fix

    Re-piping replaces the old steel with modern copper or PEX, restoring pressure and water quality for decades. It's a bigger job than a repair, but a skilled plumber plans the runs to minimise disruption. We assess how far gone your system is and advise honestly whether to repair or re-pipe — see pipe repairs or book an assessment.

    Frequently Asked Questions

    Galvanised steel pipes corrode from the inside out — rust and scale build up over decades, narrowing the pipe (reducing pressure and flow) and eventually causing leaks and discoloured water. Once internal corrosion sets in, it only worsens, which is why patching a section is a short-term fix at best.

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