Survey finding
Failed chimney flashing on your survey: what it costs
Failed flashing is a common, fixable Cat 2 item. This page covers the costs and what to ask before exchange.
Last updated: 6 May 2026. Editorially reviewed: 20 May 2026.
Finding
Chimney flashing failure
What this usually means
Lead flashing seals the joint between chimney stack and roof covering. Splitting, lifting, or missing flashing lets water track down the stack and into the roof void, causing damp staining on bedroom ceilings and timber decay around the chimney breast.
Why it matters
Flashing failure is normally a maintenance item, not a structural one. Left alone, it leads to expensive timber and plaster repairs.
Ask your surveyor
- Check:Is there evidence of internal damage from the failed flashing?
- Check:Is the flashing repairable, or does it need full replacement?
Ask the seller
- Check:Have you noticed any damp staining inside near the chimney breast?
- Check:When was the roof last maintained or inspected?
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
Maintenance item. Worth quoting and including in negotiation.
Typical cost to fix
New lead flashing £400-£900 for a typical stack including labour and scaffolding. If timber decay or plaster repair is needed inside, add £500-£1,500.
Mortgage impact
Generally none. This is a maintenance Cat 2 item. Lenders rarely retain.
Insurance impact
Damage from gradual leakage is excluded from standard buildings insurance; insurers expect maintenance.
When to pull out
Not a pull-out reason on its own.
When to renegotiate, and by how much
Ask for the cost of repair (typically £500-£1,500) as a price reduction or seller-completed before exchange.
Thinking of pulling out or renegotiating? What to do after a bad survey
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Run a free previewHow 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 hello@mypropertyscan.com 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.