Timber decay and woodworm
Can dry rot spread behind plaster without a fruiting body in the room?
Yes. Dry rot can travel in damp masonry and behind finishes, and a mushroom-like fruiting body is not always present. A musty smell, cracked paint and soft skirting can be the visible part. A survey that has not opened the wall cannot map the spread.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
The Property Care Association publishes guidance on fungal decay and a homeowner note that separates dry rot and wet rot. Dry rot needs damp timber. It is not a reason to treat a dry house “in case”. It is a reason, when the clues are real, to open up before you buy the repair. The seller has to agree to opening up.
Ask the surveyor what they saw: mycelium, a fruiting body, or only a smell and a soft board. Those are different levels of evidence. A specialist should say how far they need to look. There is no standard metre of spread we can quote, and no standard price. Beware a quote that replaces every floor from one skirting.
What should you ask your surveyor?
- What exactly did you see that made you say dry rot rather than wet rot or general damp?
- What is still hidden?
- What opening-up would you want before I rely on a price?
What are the typical next steps?
- Do not accept a whole-house treatment quote from a sentence in the survey.
- Get a specialist inspection with a written extent, after the seller agrees access.
- Stop the water. PCA’s approach is that the fungus is a symptom of damp timber.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
Is dry rot always worse than wet rot?
Dry rot can cross masonry and surprise people. Wet rot stays with the wet timber. “Worse” depends on the extent. The survey may not know the extent yet.
Can you smell which fungus it is?
A smell is a clue. Identification is visual and, if needed, by someone who knows the fungi. Do not buy a named treatment on a smell alone.