Dry Rot Treatment Specialists
Dry rot is the most serious form of fungal decay a building can suffer, and the only treatment that lasts is one that fixes the cause. We find and stop the moisture feeding it, treat the decay and repair the timber, all backed by a written guarantee.
Book a Dry Rot Survey
0300 373 7251Survey-led diagnosis with a clear, written report. No obligation.
What is Dry Rot?
Dry rot is a wood destroying fungus, Serpula lacrymans, and it is the most damaging type of timber decay found in UK buildings. It feeds on the cellulose in wood, leaving timber dry, brown, brittle and cracked into cube like shapes until it eventually crumbles to dust.
Despite the name, dry rot does not happen in dry conditions. It needs damp timber to take hold, usually once the moisture content climbs above around 20 percent. What sets it apart from wet rot is what happens next: it can send fine strands and cotton wool like growth through plaster and masonry to reach fresh timber elsewhere, so an outbreak that starts in one damp corner can travel well beyond the part you can see.
That combination, hidden spread and serious structural damage, is why dry rot needs proper diagnosis. We use a timber and damp survey to confirm what it is, find the moisture feeding it, and map how far it has gone before any work starts.
Signs of Dry Rot
Dry rot often hides in cellars, subfloor voids, roof spaces and behind panelling. These are the tell-tale signs that it may be active.
Cuboidal Cracking
Timber that has gone dark brown, dry and brittle, cracking across and along the grain into cube shapes, and crumbling easily when pressed.
Rust-Red Spore Dust
A fine, rust or orange coloured dust settling on surfaces near the outbreak, a sure sign that a fruiting body is producing spores nearby.
White Mycelium Growth
White or grey cotton wool like growth, sometimes with yellow or lilac tinges, spreading across timber or damp walls.
Strands Through Masonry
Grey, root like strands resembling spider silk, which dry rot uses to travel through brick and plaster in search of new timber.
A Fruiting Body
A soft, pancake or bracket shaped growth, often rust coloured at the centre, appearing when the fungus is well established.
A Musty, Damp Smell
An earthy, mushroom like or musty odour, often the first clue to hidden decay before anything is visible.
Dry Rot or Wet Rot?
The two are constantly confused, and getting it wrong is expensive. Wet rot stays confined to the wet timber itself and does not travel through the building, so once the damp is fixed it is usually straightforward to deal with. Dry rot is the aggressive one, able to spread through masonry to attack dry timber elsewhere.
Treating wet rot as dry rot means needless cost and disruption. Treating dry rot as wet rot means missing the spread and watching it come back. A correct diagnosis is the whole foundation of getting the work right.
Our approach: we identify exactly which fungus is present and what is feeding it before recommending anything, so you are not paying for treatment you do not need.
What Causes Dry Rot
Dry rot is always a symptom of a moisture problem. Common sources include:
How We Treat Dry Rot
Survey and diagnosis
We confirm it is dry rot, not wet rot or something less serious, identify the moisture source and establish how far the outbreak has spread, opening up where needed.
Fix the cause first
The single most important step. We stop the damp at source, whether that is rising damp, penetrating damp, a leak or poor ventilation, because without this any treatment will fail.
Remove and treat
Affected timber is cut back well beyond the last visible growth. Remaining sound timber and any affected masonry are treated to control the fungus.
Dry and ventilate
We promote drying and improve ventilation so conditions no longer suit dry rot. We use preservatives as a targeted, supplementary measure, not a substitute for fixing the damp.
Repair and protect
New pre-treated timber is installed and isolated from damp masonry, restoring the structure properly rather than just patching the surface.
Written guarantee
Completed work is backed by a written 10 year guarantee, transferable on sale and accepted by solicitors and lenders.
Why It Pays to Act Early
Dry rot does not fix itself, and the longer it is left the further it travels. Early action keeps the problem, and the repair, contained.
What Our Customers Say
Genuine reviews from Advanced Damp customers.
"I had two other damp surveys on my home and they were only interested in concluding that it was rising damp so that they could charge me a lot to inject into my walls. Matt on the other hand has proper experience and techniques with thermal imaging, and he understood what the issues really were. He gave holistic advice on how to really solve the problem, and at much less cost."
"Professional company and a great transformation. The area is a small below ground void that has a sloped cement retaining slab. They damproofed it and then came up with a great plan to add storage shelves. It looks great and has added the storage that we wanted."
"Lionel was super helpful and efficient. He sent the detailed follow-up docs the same day. Very impressed by excellent service provided by Advanced Damp, thank you."
Related Timber & Damp Services
Dry rot rarely arrives alone. These related services tackle the wider timber and moisture picture:
Dry Rot FAQs
Is dry rot serious?
Will dry rot spread through my property?
What is the difference between dry rot and wet rot?
What causes dry rot?
Can I treat dry rot myself?
Will dry rot come back after treatment?
Worried About Dry Rot?
Book a survey and get a clear, written diagnosis of what is really going on, the cause behind it and exactly what needs to be done, with no scare tactics.
Last updated June 2026 · Advanced Damp Ltd · Dry rot treatment nationwide · 0300 373 7251