Survey finding
Chimney stack movement on your survey: how to handle it
A leaning chimney is one of the most common surveyor flags on older UK housing stock. This page explains causes, costs, and what your lender will likely ask.
Last updated: .
Finding
Chimney stack movement
What this usually means
Chimney stacks are exposed to weather and gradually deteriorate. Movement can be from sulphate attack on flue gases acidifying mortar (preferential erosion on one side, causing the stack to lean), failed flashing letting water in, or weak bedding mortar. A leaning stack can drop debris, so treat it as more than a cosmetic issue.
Why it matters
If the stack is actively unstable, the lender's surveyor will require either rebuilding or removal before drawdown. It is one of the most common items lenders condition mortgage offers on.
Ask your surveyor
- Check:Is the movement historic and stable, or is the stack at risk in current condition?
- Check:Can you tell whether the cause is sulphate attack, flashing failure, or settlement of the supporting wall?
Ask the seller
- Check:When was the chimney last repointed or rebuilt, if ever?
- Check:Has the chimney been used as a flue, or is it disused and capped?
Next steps
- •Get two written quotes from local trades before negotiating with the seller.
- •Speak to your mortgage broker before exchanging if the finding affects mortgageability.
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What you need to know
Severity
Significant. Specialist follow-up usually warranted before exchange.
Typical cost to fix
Stack rebuild from above the roofline typically £1,800-£4,500 including scaffolding. Full removal and roof making-good £2,500-£5,500. Repointing and flashing repair only £600-£1,500 if structure is still sound.
Mortgage impact
Many lenders impose a retention until repair is complete; some accept a structural engineer's letter confirming short-term stability with a 6-month repair condition.
Insurance impact
Standard buildings insurance covers chimney damage; insurers usually want to see the stack is sound at point of policy inception.
When to pull out
Rarely a deal-breaker on its own. Pull out only if the stack issue is part of a wider pattern of structural failure.
When to renegotiate, and by how much
Ask for the rebuild cost plus 10-15% buffer, or have the seller complete the works before exchange.
Thinking of pulling out or renegotiating? What to do after a bad survey
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The Survey Decoder explains the wording. The full report adds address-specific flood, subsidence, EPC, crime, listed status, building age and price comparison data, so a single finding isn't judged in isolation.
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Check the property before you offer
Free preview: flood risk, EPC rating, crime, tenure and air quality. The £9.99 report adds the remaining 17 checks, 22 in all, drawing on up to 15 public datasets.
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How MyPropertyScan produces this guide, and what it is not
Published by MyPropertyScan and written by Ziad Nasr, who is accountable for its accuracy. No page here is written or reviewed by a chartered surveyor, conveyancer or regulated adviser, and we do not claim otherwise.
This page is not:
- Chartered surveying: we do not inspect properties or produce RICS Home Survey reports
- Legal advice: we do not act as conveyancers or advise on title, tenure or contracts
- Mortgage or insurance advice: we are not regulated by the FCA and give no recommendations
Figures and process steps come from the published UK datasets and standards listed on this page, not from professional practice. Pages are updated when source coverage, survey cost assumptions, or lender and legal requirements materially change. Dataset limitations are set out on the methodology page.
Spotted something out of date or wrong? Email [email protected] and we will correct it and change the update date.
Sources used
We use UK public and specialist sources where they are available. Public datasets can be incomplete, delayed, or missing for some addresses. Treat them as a starting point, not as a replacement for professional advice.
Source standard: preference goes to official government datasets, statutory bodies, professional standards, and primary dataset publishers. We cite the source family on the page and explain coverage limits rather than filling gaps with unsupported estimates.
- Professional standard: RICS Home Survey StandardRICS standard for condition-based residential surveys in the UK.
- Learn more from: RICS consumer guide to surveysConsumer-facing guide to survey types and when each level is appropriate.
- Official guidance: GOV.UK buying or selling your homeGovernment overview of the home buying and selling process.