Survey finding
Dry rot on your survey: how serious is it?
Dry rot is the most serious timber-decay fungus. This page covers identification, cost of treatment, and when to walk away.
Last updated: 6 May 2026. Editorially reviewed: 20 May 2026.
Finding
Dry rot (Serpula lacrymans)
What this usually means
Dry rot is a fungal attack on timber that occurs in damp, poorly ventilated conditions. Unlike wet rot, dry rot can spread through masonry to find new timber, and is therefore taken seriously. Visible signs: orange-brown fruiting bodies, white mycelium strands, cuboidal cracking of timber.
Why it matters
An active dry rot outbreak requires source control (fix the moisture ingress), removal of affected timber with a margin, and timber treatment. Lenders take it seriously.
Ask your surveyor
- Check:Is the outbreak active or historic?
- Check:Have you identified the moisture source?
Ask the seller
- Check:Has the property had any damp or timber treatment, with guarantees?
- Check:Is the area where the outbreak was found regularly 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
Serious. Lender and insurer involvement likely; structural or specialist remediation.
Typical cost to fix
Specialist survey £200-£600. Localised outbreak treatment £1,500-£4,000. Extensive outbreak with structural timber replacement £8,000-£20,000+.
Mortgage impact
Lender retention until treatment is complete with guarantee. Most insist on PCA-member firms.
Insurance impact
Generally excluded as a maintenance issue, though source-event damage may be covered.
When to pull out
Walk away if dry rot is extensive and the seller refuses to fund treatment, or if structural timbers are extensively compromised.
When to renegotiate, and by how much
Quoted treatment cost plus 20% buffer; typical reductions £3,000-£15,000+.
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.