CSSW & FODCS trained surveyors
Timber Treatment Specialists
Dry rot, wet rot and woodworm all start the same way: moisture in the timber. We identify which one you actually have, find the water feeding it, and treat only what needs treating. Backed by a written 10 year guarantee.
Timber Treatment In Short
Timber treatment is the diagnosis and remedy of the three things that damage structural wood in UK buildings: dry rot, caused by the fungus Serpula lacrymans; wet rot, most often caused by the cellar fungus Coniophora puteana; and woodworm, the larval stage of wood-boring beetles such as the Common Furniture Beetle, Anobium punctatum. All three are caused by excess moisture in the timber.
Treatment involves identifying which of the three is present, cutting out and replacing any timber that has lost structural strength, applying an appropriate fungicidal or insecticidal treatment to sound timber at risk, and correcting the moisture source that allowed the decay. Timber treatment carried out without resolving the moisture source will fail.
Advanced Damp Ltd carries out survey-led timber treatment across London, the South East and the Midlands, with a written 10 year guarantee on completed work.
Start here
Which Timber Problem Do You Have?
Three very different problems get lumped together as timber treatment. They need different answers, and treating the wrong one wastes your money. Pick the closest match, or call and describe what you are seeing.
Dry Rot Treatment
- Deep cracking across the grain, timber breaking into brick-shaped cubes
- Rusty red spore dust and a heavy, musty, mushroom-like smell
- White or grey strands spreading over brick and plaster, not just wood
- The most serious of the three, because it can travel away from the original damp
Wet Rot Treatment
- Soft, spongy, darkened timber that gives way under a screwdriver
- Often hidden behind sound-looking paint on sills, frames and skirtings
- Stays confined to the wet timber rather than spreading through masonry
- The most common timber decay in UK homes, and usually leak-driven
Woodworm Treatment
- Small round exit holes, typically 1mm to 2mm across
- Fine powdery frass around or below the holes
- Beetles appearing indoors from spring to early autumn
- Often historic and needing no treatment at all, which is why it gets checked first
Not sure which one you are looking at? That is normal, and it is exactly what a damp and timber survey is for.
Quick comparison
Dry Rot, Wet Rot and Woodworm Side by Side
The differences that actually change what the work costs you and how urgent it is.
| Dry Rot | Wet Rot | Woodworm | |
|---|---|---|---|
| Cause | Dry rot is caused by the fungus Serpula lacrymans growing in persistently damp, poorly ventilated timber. | Wet rot is caused by several fungi, most often the cellar fungus Coniophora puteana, in timber kept wet by a leak or building defect. | Woodworm is caused by the larvae of wood-boring beetles, most often the Common Furniture Beetle, Anobium punctatum. |
| What you see | Dry rot shows cuboidal cracking across the grain, rusty red spore dust, white or grey strands, and a strong musty smell. | Wet rot shows soft, dark, spongy wood, frequently hidden beneath intact paint. | Woodworm shows round exit holes of roughly 1mm to 2mm, powdery frass beneath them, and weakened timber. |
| How far it travels | Dry rot can spread through masonry and plaster to reach dry timber some distance from the original damp. | Wet rot stays within the wet timber itself, so the damage remains contained. | Woodworm spreads to adjacent timber as adult beetles emerge and lay eggs nearby. |
| Urgency | Dry rot is the most urgent of the three. Delay usually means more timber lost and a wider strip-out. | Wet rot is moderately urgent. It is contained, but timber left wet long enough can go on to invite dry rot. | Woodworm urgency depends entirely on whether the infestation is active or historic. Historic infestations need no treatment. |
| Typical treatment | Dry rot is treated by cutting out affected timber, exposing and drying the structure, applying fungicidal treatment, and replacing in pre-treated wood. | Wet rot is treated by removing the water source, then cutting out or consolidating the affected timber before treating and reinstating. | Woodworm is treated with insecticide where the infestation is active, replacing weakened structural timber and correcting the underlying damp. |
| Fixing the damp | Fixing the moisture source is non-negotiable in all three cases. Timber treatment carried out without resolving the moisture source is a repeat visit waiting to happen. | ||
What to look for
Signs Your Timber Needs Attention
Timber decay is usually well advanced before it becomes obvious, because most of it happens out of sight in floors, roof voids and behind skirtings.
Bouncy or Springy Floors
Movement underfoot, particularly near external walls, bay windows or bathrooms, often points to decayed joist ends.
Soft, Crumbling Wood
Skirtings, sills, frames or joists that give way when pressed with a screwdriver, even where the paint still looks sound.
A Musty, Earthy Smell
A persistent damp or mushroom-like smell in a cellar, under stairs or in a room with no obvious damp patch.
Round Holes and Dust
Small round holes in floorboards, joists or furniture, with fine powdery dust collecting beneath them.
Fungal Growth on Timber
White strands, cotton-wool-like growth, or a fruiting body with rusty red dust around it. Treat this as urgent.
Damp Nearby
A known leak, blocked gutter, failed damp proof course or badly ventilated subfloor. Where the water goes, decay follows.
Found Something You Are Not Sure About?
Send us a photo or describe what you are seeing. If it warrants a survey we will tell you, and if it does not, we will tell you that too.
How it works
Our Timber Treatment Process
The same five stages whether it turns out to be dry rot, wet rot or woodworm. The diagnosis decides the middle, not the method.
Survey and diagnose
A CSSW and FODCS trained surveyor inspects the affected timber, takes moisture readings, opens up subfloor and roof voids where access allows, and identifies the decay or beetle species present.
Trace the moisture
We find what is wetting the timber, whether that is a leak, a defective damp proof course, external water ingress or poor ventilation. Thermal imaging is used where the source is not visible.
Written report and scope
You receive a clear written report with photographs, the diagnosis, and a defined scope of works. No pressure to proceed and no work recommended that the evidence does not support.
Treat and repair
Affected timber is cut out and replaced in pre-treated wood where strength has been lost, sound timber is treated with the appropriate fungicide or insecticide, and the moisture defect is corrected.
Reinstate and guarantee
Areas opened up are made good, the site is left clean, and the completed work is backed by a written 10 year guarantee that is transferable on sale and accepted by solicitors and lenders.
One contractor throughout
Survey, diagnosis, treatment and reinstatement are handled by the same team, so nothing gets lost between a surveyor who diagnosed it and a builder who never saw the report.
The part most people miss
Timber Treatment Only Lasts if the Damp Is Fixed
Sound, dry timber is not attacked. Every case of dry rot, wet rot and woodworm we attend has a moisture source behind it, and if that source is left in place the timber will decay again regardless of what was sprayed on it.
That is why we are a damp proofing contractor that treats timber, rather than a timber treatment firm that ignores damp. The survey looks for the cause first, and the treatment plan deals with both.
Common moisture sources behind timber decay include rising damp in ground floor walls and joist ends, penetrating damp from defective pointing, gutters or roof coverings, and condensation in cold, poorly ventilated roof and subfloor voids. Where a leak is suspected but not visible, a thermal imaging survey narrows it down without unnecessary opening up, and where airflow is the underlying issue we specify ventilation improvements as part of the works.
What You Get
- A named CSSW and FODCS trained surveyor
- Written report with photographs
- Species and activity confirmed before any treatment
- The moisture cause identified, not just the symptom
- A defined scope of works with clear exclusions
- Written 10 year guarantee on completed work
- Transferable on sale, accepted by solicitors and lenders
- One contractor from survey to reinstatement
Verified feedback
What Our Customers Say
Genuine reviews from Advanced Damp customers.
"Lionel was brilliant. Expert, efficient and extremely helpful in answering our various queries."
"Great communication throughout the process and Lionel, who came to do the survey was prompt, extremely polite, informative... the report was sent couple days later as promised."
"...found a leak in our roof and made it easier to relay that information to the roof guy."
Related services
Timber and Damp Services We Provide
Timber decay rarely arrives on its own. These are the services that most often sit alongside it.
Dry Rot Treatment
Identification, containment and full treatment of Serpula lacrymans, including the masonry it travels through.
Wet Rot Treatment
Removing the water source, cutting out or consolidating decayed timber, and reinstating sills, joists and frames.
Woodworm Treatment
Species identification, active or historic assessment, and insecticidal treatment only where it is genuinely needed.
Damp and Timber Survey
Non-invasive inspection with moisture readings and a written report identifying the cause, not just the symptom.
Damp Proofing
Damp proof course installation and replastering where rising or penetrating damp is feeding the timber decay.
Ventilation
Subfloor, roof void and whole property ventilation to keep timber dry once treatment is complete.
Common questions
Timber Treatment FAQs
What is timber treatment?
Timber treatment covers the diagnosis and remedy of the three things that damage structural wood in buildings: dry rot, wet rot and wood-boring beetle infestation, commonly called woodworm. In practice it means identifying which is present, cutting out and replacing any timber that has lost its strength, applying an appropriate fungicidal or insecticidal treatment to sound timber at risk, and correcting the moisture problem that allowed the decay in the first place.
How do I know whether I have dry rot or wet rot?
The clearest distinction is how far it travels. Wet rot stays in the timber that is actually wet, so the damage is contained to a sill, a joist end or a section of skirting. Dry rot can spread strands through brickwork and plaster to reach dry timber some distance from the original leak, which is why it is the more serious of the two. Visually, dry rot cracks deeply across the grain into cube-shaped pieces and produces rusty red spore dust, while wet rot leaves timber dark, soft and spongy. Both can hide under intact paint, so a physical inspection is the only reliable way to tell.
Does woodworm always need treating?
No, and this is where a lot of money gets wasted. Plenty of properties carry exit holes from an infestation that died out years or decades ago and needs no treatment at all. Active infestation shows clean, pale, sharp-edged holes, fresh powdery frass, and beetles emerging between spring and early autumn. Historic damage shows darker, dusty holes and no fresh frass. Establishing which you have is the first job of the survey, and if it turns out to be historic we will tell you so.
Do you have to replace the affected timber?
Only where it has lost structural strength. Timber that is decayed but still sound in section can often be treated and left in place, and in some wet rot cases a resin repair or hardener is appropriate. Joists, beams, wall plates and floorboards that have been significantly weakened are cut back beyond the affected area and replaced with pre-treated timber. The survey sets out exactly what is coming out and what is staying before any work starts.
How long does timber treatment take?
A localised wet rot repair to a window sill or a single joist end is often a one day job. Woodworm treatment to a floor or roof void is typically one to two days. Dry rot is the variable one, because the extent of the outbreak is only fully known once the affected area is opened up, and drying the structure takes time before reinstatement. Your report will give a realistic programme for your specific property rather than a generic figure.
Is timber treatment guaranteed?
Yes. Completed timber treatment is backed by a written 10 year guarantee. It is transferable if you sell the property and is accepted by solicitors and lenders during a sale, which matters if the decay was picked up in a buyer survey. The guarantee is conditional on the specified moisture remedy being carried out, because treating timber while leaving the water source in place is not a durable repair.
Book a survey
Get a Straight Answer on Your Timber
A CSSW and FODCS trained surveyor will identify what you are dealing with, find the moisture behind it, and set out in writing what actually needs doing. Including, where that is the honest answer, nothing.
Non-invasive survey with a clear written report. No obligation.
Advanced Damp Ltd · Timber treatment across London, the South East and the Midlands · 0300 373 7251