Wet Rot Treatment London — Diagnosis, Repair & Guaranteed Prevention
Wet rot is the most common form of timber decay in London properties — but it will not stop on its own. Our PCAQT-certified specialists identify the moisture source, assess all affected timber, carry out structural repairs where needed, and guarantee the result.
Fixed-fee survey · Written report included · No obligation to proceed · Guaranteed works available
Understanding the problem
What Is Wet Rot — and Why Does the Moisture Source Matter Most?
Wet rot is caused by several species of wood-decaying fungi that attack timber with a sustained moisture content above 30%. Unlike dry rot, it cannot spread through masonry or generate its own moisture — which means eliminating the moisture source will halt active decay. But it will not reverse the structural damage already done.
This is the most misunderstood aspect of wet rot treatment. Many homeowners fix the leak, repaint over the staining, and assume the problem is solved. It isn’t. Timber that has undergone fungal decay retains weakened cell structure — it may look intact at the surface while carrying significantly reduced load capacity beneath. A professional assessment of all affected timber is essential before any repair work begins.
Wet rot typically begins when sustained moisture — from a leak, rising ground water, inadequate ventilation, or failed external fabric — keeps timber above the critical 30% moisture content threshold over a prolonged period. London’s older Victorian and Edwardian housing stock is particularly susceptible, given suspended timber ground floors, original sash window frames, and aging guttering and drainage systems.
Common wet rot species in UK properties
Cellar Fungus
Coniophora puteana
The most prevalent wet rot species in UK buildings. Produces dark brown to black mycelium strands on the surface of timber — finer and darker than dry rot growth, and confined to the moisture zone. Timber darkens and develops longitudinal cracking along the grain.
Most common in LondonMine Fungus
Fibroporia vaillantii
Produces white, cottony mycelium — occasionally confused with dry rot by untrained inspectors. Requires very high moisture levels and is most often found in poorly ventilated subfloor voids and cellar timbers. Does not spread through masonry.
Subfloor & cellar areasWhite Wet Rot
Phellinus contiguus & others
A group of white rot fungi that attack lignin as well as cellulose, leaving bleached, fibrous timber rather than the characteristic brown crumbling of brown rot species. Common in external joinery — window frames, external door frames, and fascia boards.
External joineryWarning signs
Signs of Wet Rot in Your Property
Wet rot often develops in areas that aren’t regularly inspected — under floors, in roof voids, behind skirting boards, and within external joinery. These are the indicators to look for.
Longitudinal timber cracking
Cracks running along the grain — unlike the block-like cuboidal cracking of dry rot. Timber is soft, spongy, or crumbles easily when probed with a screwdriver or knife
Dark discolouration
Affected timber turns darker than surrounding wood. The darkening follows the moisture distribution — heaviest at the leak source and diminishing outward
Paint failure on joinery
Bubbling, flaking, or cracking paint on window frames, sills, or external doors — particularly at joints and end grain — often indicates wet rot establishing beneath the surface
Soft or springy flooring
Noticeable flex or bounce in floorboards — especially in older London properties with suspended timber ground floors — suggests joist decay below. A serious structural indicator
Dark mycelium strands
Fine, dark brown-to-black fungal strands on timber or surrounding materials — finer and darker than dry rot mycelium, and confined to the moisture-affected zone
Persistent earthy or musty smell
A damp, mushroom-like odour that persists after ventilation — particularly in underfloor voids, cellars, and around window reveals — indicates active or recently active decay
Root causes
What Causes Wet Rot in London Properties
Wet rot is always a symptom of a sustained moisture problem. Treat the timber without resolving the moisture source and the fungus will re-establish. These are the most common causes we identify in London properties.
🪟 Failed window & door frames
Degraded paint, failed putty, and open joints allow sustained water ingress into end grain — the primary entry point for wet rot in London’s Victorian sash windows and Edwardian external doors
🏠 Leaking or blocked gutters
Overflowing gutters saturate fascia boards, rafter feet, and wall plates. One of the most consistent sources of wet rot in London terraced housing — often unnoticed for years
🚿 Wet room failures
Failed shower trays, leaking waste pipes, and unsealed bath panels allow persistent moisture into the subfloor structure beneath bathrooms and kitchens
🏗️ Flat roof failure
Cracked or failed flat roof membranes and blocked outlets allow standing water contact with roof joists and deck timbers — typically undiscovered until significant decay has occurred
🌬️ Blocked subfloor ventilation
Air bricks blocked by raised external ground levels, built-up soil, or debris trap moisture under suspended timber floors — a very common condition in pre-1950 London housing
🧱 Defective pointing & render
Failed mortar joints and cracked render allow penetrating damp to saturate embedded timber — wall plates, lintels, and any timber built into masonry in older London properties
Structural risk assessment
How Serious Is Your Wet Rot — Assessing Structural Risk
Not all wet rot carries the same structural risk. The severity depends on which timber is affected, how long decay has been active, and what load that timber carries. This is why a professional assessment — not just fixing the moisture source — is essential.
Soft Floorboards? Failed Window Frames? Don’t Delay.
Structural timber affected by wet rot needs professional assessment — not just a new coat of paint. Same-week surveys across London.
Our treatment process
How We Treat Wet Rot — A Five-Stage Process
The moisture source must be resolved before any timber work begins — treating the wood without fixing the cause is the single most common reason wet rot returns. Every stage of our process is documented.
Survey & Moisture Mapping
Calibrated moisture meters used throughout — identifying all affected timber, the full decay boundary, and the moisture source driving it
Full extent mappedMoisture Source Eliminated
Leak repaired, ventilation improved, failed fabric fixed — before any timber is touched. The fungus cannot persist in timber below 20% moisture content
Root cause resolved firstStructural Assessment
Each affected timber probed and assessed for residual load capacity. Structural elements — joists, wall plates, rafter feet — treated with greater safety margins than non-structural joinery
Load-bearing focusRemoval & Replacement
Structurally compromised timber removed and replaced with pre-treated equivalent. Minor joinery decay may be stabilised with consolidant where structural integrity is confirmed
Pre-treated timber usedPreservative Treatment & Report
Adjacent at-risk timbers treated with boron-based preservative. Written report and guarantee issued — delivered within 48–72 hours of completion
Written guarantee issuedWhy choose us
Why London Homeowners & Landlords Use Damp & Mould Solutions
Many wet rot treatments fail because the moisture source is never found, or because a visual inspection misses decay hidden beneath a sound-looking surface. Our PCAQT-certified specialists use calibrated equipment and a structured methodology.
🎓 PCAQT-Certified Specialists
PCAQT — Property Care Association Qualified Technician — is the UK industry qualification for timber decay and damp specialists. Every survey and treatment is carried out by a qualified professional, not a general tradesperson.
🔬 Moisture Source First, Always
We will not start timber repairs until we have identified and resolved the moisture source. This is the single most important step in preventing recurrence — and the step most commonly skipped by non-specialist contractors.
📐 Calibrated Moisture Mapping
We use calibrated moisture meters throughout the property — not a visual inspection and an estimate. This ensures all affected timber is identified, including decay hidden behind intact paint or under floor coverings.
📋 Written Report & Guarantee
Every job produces a written report — photographs, moisture readings, diagnosis, works carried out, and a guarantee. The documentation is yours to use with your insurer, solicitor, or any subsequent contractor.
📅 Same-Week Surveys
We cover most London boroughs and typically book within the same week. If you’re under time pressure — a property purchase, a tenant complaint, or an insurance claim — call us directly and we’ll prioritise.
🤝 No Over-Specification
We’ll tell you if the decay is minor and a consolidant repair is sufficient — we won’t recommend full joist replacement when it isn’t needed. Our report reflects what we find, not what generates the most work.
Who we work with
Homeowners, Buyers, Landlords & Managing Agents
Accurate diagnosis before you spend money
- Pre-purchase wet rot surveys with rapid turnaround
- Surveyor-flagged timber decay independently assessed
- Written report for mortgage lenders and solicitors
- Clear cost estimates — no vague ranges, no hard sell
- Advice on what needs replacing vs what can be stabilised
- Guarantee documentation transferable on property sale
Structural timber decay is a Section 11 liability
- Section 11 LTA 1985 requires landlords to maintain structural integrity
- HHSRS-aware reports suitable for council and legal use
- Direct tenant liaison — your attendance not required
- Multi-property and HMO surveys accommodated
- Compliance documentation for landlord files
- Portfolio inspection arrangements available
Where we work
Wet Rot Specialists Covering Greater London
We cover most of Greater London and Hertfordshire. Particularly active across North, North West, West, and Central London. Call us to confirm availability for your borough.
North London
Barnet · Finchley · Hendon · Golders Green · Mill Hill · Edgware · Colindale · High Barnet
North East London
Haringey · Wood Green · Tottenham · Hackney · Enfield · Barking & Dagenham
West London
Ealing · Chiswick · Acton · Greenford · Kensington · Hammersmith · Fulham · Chelsea
North West London
Wembley · Willesden · Harlesden · Kilburn · Queens Park · Brent
Central London
Camden · Hampstead · Belsize Park · Kentish Town · St John’s Wood · Islington
Hertfordshire
St Albans · Hemel Hempstead · Bishop’s Stortford · Hertford
What customers say
Trusted by London Homeowners, Buyers & Landlords
Our ground floor had that slight bounce that had been there for years. Turned out two joists had significant wet rot from a blocked air brick we’d never found. The survey identified it, the source was fixed, and the joists replaced in three days. Wish we’d done it sooner.
Buying a Victorian terrace — the surveyor flagged possible timber decay in the front bay. Damp & Mould Solutions came in two days, confirmed wet rot in the window sill and one joist end, gave us a proper report with photos and a fixed quote. The sellers covered it in the negotiation.
As a landlord I’ve used several companies over the years. These are the only ones who identified the blocked gutters as the cause before touching the timber. Previous treatments always failed because nobody fixed the actual problem. This one hasn’t come back.
Questions answered
Wet Rot Treatment — Frequently Asked Questions
How much does wet rot treatment cost in London?
If I fix the leak, will the wet rot stop?
How do I know if it’s wet rot or dry rot?
Can wet rot spread to neighbouring properties?
My window frames have wet rot — do they need full replacement?
How long does wet rot treatment take?
A previous contractor treated the wet rot and it came back. Why?
Book your survey
Book a Wet Rot Survey in London
Speak to a PCAQT-Certified Specialist
Tell us what you’ve noticed — soft timber, failed paint, a spring in the floor, or what a surveyor has flagged. We’ll advise on whether a specialist survey is the right next step before you commit to anything.
💡 Tip: Send photos of the affected timber to info@dampandmouldsolutions.co.uk before booking — we can often advise on urgency and likely scope before we visit.
Request a Wet Rot Survey
Fill in your details and we’ll get back to you promptly — typically within a few hours during business hours.
Get Your Wet Rot Diagnosed and Treated This Week
PCAQT-certified specialists, moisture source eliminated first, written report and guaranteed works — London-wide coverage.