Survey finding
Wet rot on your survey: what it means and what to do next
Wet rot is one of the most common timber-decay findings on UK surveys, and the most often misdiagnosed. This page sets out what wet rot is, how it differs from dry rot, what fixing it costs, and how mortgage lenders treat it.
Last updated: 6 May 2026. Editorially reviewed: 20 May 2026.
Finding
Wet rot
What this usually means
Wet rot (most often Coniophora puteana, the cellar fungus) is the most common form of fungal timber decay in UK houses. It thrives where timber has been wetted by a leak, condensation, or rising damp and stays damp continuously. Affected timber turns dark, splits along the grain (cuboidal cracking), and crumbles when probed. Unlike dry rot, wet rot does not spread through dry masonry, fix the moisture source and the rot stops.
Why it matters
Wet rot is treatable. The headline buyer concern is finding the moisture source and assessing how much structural timber has been compromised. Mortgage lenders generally treat localised wet rot as standard; widespread wet rot affecting structural members may trigger a retention.
Ask your surveyor
- Check:Can you identify the moisture source, leak, condensation, rising damp, blocked airbrick?
- Check:Is the rot localised or has it affected structural timbers?
Ask the seller
- Check:When was the affected area last inspected, and have any repairs been carried out?
- Check:Have you experienced any leaks or moisture problems in this part of the property?
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.
Browse all findings
- Spray foam insulation
- Evidence of movement
- Damp
- Japanese knotweed
- Damp proof course issues
- Underpinning
- Cracks
- Roof issues
- Timber decay
- Electrical issues
- Non-standard construction
- Asbestos containing materials
- Roof covering needs repair
- Single skin wall construction
- Timber decay / wet rot
- Settlement cracks
- RAAC concrete
- Wall tie failure
- Party wall matters
- Drainage issues
- Subsidence monitoring
- Full electrical rewire needed
- Flat roof condition
- Cladding issues
- EWS1 form required
- Lintel failure
- Structural crack BRE category 3
- Structural crack BRE category 4-5
- Chimney stack movement
- Chimney flashing failure
- Parapet wall movement
- Bay window cracking
- Flat roof ponding
- Cold roof inadequate ventilation
- Warm roof insulation issues
- Prefab concrete construction
- Large panel system (LPS) construction
- Rising damp
- Penetrating damp
- Condensation vs damp distinction
- Dry rot (Serpula lacrymans)
- Woodworm
- Timber floor springiness
- Cellar / basement damp
- Outdated electrics (60-amp fuse board)
- Aluminium wiring
- Partial rewire needed
- Gas boiler condition
- Back boiler
- Unvented hot water cylinder issues
- Lead pipes (pre-1970)
- Lead paint
- Asbestos in Artex ceilings
- Asbestos floor tiles
- Asbestos cement roof
- Asbestos insulated board (AIB)
- Asbestos soffit boards
- Pointing / repointing needed
- Render cracking
- Pebbledash delamination
- UPVC window seal failure
- Sash window condition
- Flat roof membrane condition
- Zinc roof
- Felt roof condition
- Corrugated asbestos roof
- Cavity wall insulation issues
- External wall insulation issues
- No building regulations certificate
- No planning permission for extension
- Certificate of lawfulness needed
- Indemnity insurance required
- Neighbour dispute on file
- EPC F or G rating
- Oil heating property
- Off-gas-grid property
- Solar panel lease vs owned
- Ground source heat pump property
- Air source heat pump property
- Chimney breast removed without support
- Floor joist decay
- Wall bowing
- Mould and condensation
- Septic tank property
- Thatched roof condition
- Listed building restrictions
- Conservation area restrictions
- Restrictive covenants on title
- Coal mining area
- Coastal erosion risk
- Flood risk zone 3
- Radon affected area
- Contaminated land history
- Trees near building
- Party wall agreement outstanding
- EICR required
- Knotweed treatment history
- Single glazing condition
- RCD protection missing
- Damp-proofing guarantee transferability
- PRC (precast reinforced concrete) house
- Airey house
- BISF (British Iron and Steel Federation) house
- Timber frame construction
- Steel frame house
- Wet rot
- Heave (ground movement)
- Chimney condition and stability
- Short lease (under 80 years)
- Fire safety: flat and leasehold issues
- Blocked or condemned flue
- Spalling brickwork
- Diagonal cracks in walls
- Retaining wall condition
- Tanking failure in basement
- Missing or slipped ridge tiles
- Lead flashing condition
- Gutters and downpipes
- Double glazing condensation (failed units)
- Skylight or roof light condition
- Dormer condition and weathering
- Torn or missing sarking felt
- Chancel repair liability
- Easement or right of way
- Boundary dispute or unclear boundary
- Adverse possession risk
- Flying freehold
- Ground rent escalation clause
- High or variable service charge
- Extension without planning consent
- Loft conversion: no building regs
- Single-phase electrical supply only
- Shared or private sewer
- Blocked or collapsed drains
- Cesspit or septic tank
- Solid fuel heating
- No mains gas supply
- Low water pressure
- Private water supply
- Wimpey No-Fines concrete house
- Reema construction
- Unity or Boot construction
- Laing Easiform
- Cornish Unit house
- Cross-wall construction
- In-situ concrete construction
- Oak frame construction
- Radon: mitigation required
- Missing or inadequate fire alarms
- Single staircase: means of escape
- No earthing or bonding
Tool shortcut
Check the property before you offer
Flood, subsidence, EPC, crime, schools, transport, broadband, tenure, age, listed status and price checks where data is available.
Run a free previewCross-check this finding with EPC, building age, and address-specific risk data.
What you need to know
Severity
Significant. Specialist follow-up usually warranted before exchange.
Typical cost to fix
Localised wet rot repair (door frame, window cill, isolated joist end): £400–£2,000 including making good. Multiple joist ends or sub-floor timbers: £2,500–£8,000+. A timber and damp specialist's survey runs £150–£400 and is widely worthwhile before any chemical treatment is paid for.
Mortgage impact
Most mainstream UK lenders accept wet rot as a standard finding subject to remediation. Where the rot affects structural timbers (joist ends, lintel timbers, floor plates). The lender may require completed works before drawdown or impose a retention.
Insurance impact
Wet rot is not generally an insurance issue except as a consequence of an insured event (escape of water, storm damage). Pre-existing wet rot is the buyer's responsibility unless the seller's home insurance has accepted a claim.
When to pull out
Pull out only if multiple structural members are affected, the moisture source is fundamental (e.g. lack of damp-proof course, rising damp throughout). The cost approaches 5%+ of purchase price, and the seller refuses to engage.
When to renegotiate, and by how much
Get a written specialist quote covering moisture-source remediation plus timber replacement and treatment. Negotiate on quote plus 15% buffer. Typical settled outcome is the full quote deducted from price, with the seller funding any larger structural element.
Thinking of pulling out or renegotiating? What to do after a bad survey
Run the check on this address
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.
Run the check
Check the property before you offer
Flood, subsidence, EPC, crime, schools, transport, broadband, tenure, age, listed status and price checks where data is available.
Run a free previewRead next
Dry rot (Serpula lacrymans) , often sits near wet rot on a survey and is the next thing to check.
Editorial review
Editorial owner: BiteRight Ltd, operator of MyPropertyScan. We review buyer guides against UK public property datasets, RICS survey wording, lender requirements, and common buyer questions.
Pages are updated when source coverage, property-risk guidance, survey cost assumptions, or product checks materially change. Methodology and dataset limitations are explained on the MyPropertyScan methodology page.
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.