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    Renovation
    Updated
    Last updated: 30 June 2026

    Hidden surprises in bathrooms

    Subfloors, leaks, old pipework - what's often found behind old bathrooms.

    At a glance

    4 min read
    Best for: Homeowners planning a bathroom renovation
    Key risk: Common specification errors that lead to costly changes
    Key takeaway: Understand what are you likely to find behind my old bathroom.

    Quick Checklist

    Key points at a glance

    • 1Budget 10-15% contingency
    • 2Expect something unexpected
    • 3Old lead pipes may need replacing
    • 4Rotten subfloors are common
    • 5Asbestos possible in older homes

    Questions to ask your installer

    Take these to your next conversation with your fitter

    • 1What are you likely to find behind my old bathroom?
    • 2How much contingency should I budget?
    • 3What happens if you find asbestos?
    • 4Who decides how to handle unexpected issues?
    • 5Will you document what you find with photos?
    • 6Are subfloor repairs included in your quote?

    💡 Tip: A good installer will welcome these questions. If they dismiss them, that's a red flag.

    💡Myth vs Reality

    Common Myth

    "If nothing is leaking, everything is fine"

    The Reality

    Slow leaks cause rot and damage over years without visible signs until you investigate.

    Common Myth

    "It's cheaper to leave old pipes"

    The Reality

    Old pipes often fail shortly after renovation. Better to replace while everything is accessible.

    What to look for

    • •Condition of floor joists and subfloor
    • •Old lead or iron pipework that needs replacing
    • •Previous leak damage and damp
    • •Outdated wiring that doesn't meet current regulations

    Common mistakes

    • •Having zero contingency budget
    • •Refusing to deal with issues when they're exposed
    • •Covering up problems to 'save money'
    • •Not authorising investigation work before the project

    Quality considerations

    • •Experienced installers can often predict what they'll find
    • •Dealing with issues now prevents bigger problems later
    • •Photos of hidden work are valuable records for the future
    • •Honest assessment of conditions shows integrity

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    This guide is written to help you make informed decisions, not to sell you anything. Always discuss your specific situation with a qualified installer.