Recognise warning signs in garden walls and know when to seek a surveyor or structural engineer.
Applies to: UK homeowners; visual symptoms cannot establish structural safety.
Last checked: 16 October 2026
Key points
• A visibly leaning, bulging or unstable wall can be dangerous.
• GOV.UK advises expert assessment for wider cracks and certain through-wall or pier cracks.
• Do not conceal structural movement with repointing before finding the cause.
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Signs needing prompt attention
Watch for movement or lean, bulging sections, open or widening cracks, loose coping stones, damage around gates, crumbling masonry or exposed foundations. If a wall appears at risk of collapse, keep people away and seek urgent professional advice.
Common causes to investigate
Possible causes include poor foundations, tree roots, drainage leaks, vehicle impacts, water and frost damage, altered ground levels or excessive loads. A photo alone cannot reliably identify which applies.
What to do next
• Keep children, pets and vehicles away from an unstable wall.
• Take dated photographs without touching or pushing the wall.
• Ask a competent structural professional about major movement or a retaining wall.
• Confirm who owns the structure and whether party-wall requirements apply before shared-wall work.
• Get a written repair or rebuilding proposal rather than just a cosmetic patch.
Official sources
Use these official sources for the current detail that applies to your job, contract or location.
BuildPair provides general information and signposting, not legal, structural, electrical, gas or building-control approval. Requirements can change and the right answer depends on the work, contract, location and facts.
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