Timber decay and woodworm
What is the difference between old flight holes and fresh bore dust for a buyer?
Old holes with no fresh dust usually mean an attack that is not active now. Fresh, pale dust on the timber or on the floor below means insects have emerged recently. A surveyor should say which they saw. “Woodworm” alone does not say whether anything is still happening, and a spray quote that ignores the difference is not a diagnosis.
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 treats moisture as part of the problem. Dry, historic holes in sound sapwood are often left. Fresh dust in damp timber is a reason to look harder and to find the moisture. A single visit can miss dust that has been cleaned, and can mistake builder’s grit for frass. Ask what the surveyor actually saw.
Do not demand treatment of every hole in a Victorian house. Do not ignore fresh dust because the holes are “just old houses”. If the report is unclear, ask one question: was the dust fresh, and in which room? Then let a timber specialist confirm. There is no PCA national tariff. Activity and the section of the timber decide the work.
What should you ask your surveyor?
- Did you see fresh dust, old holes, or both?
- Which timbers, and were they damp?
- Are you recommending treatment or only recording historic holes?
What are the typical next steps?
- Ask the surveyor to be specific if the report only says “woodworm noted”.
- Do not sweep the dust away before a specialist has seen it, if you have agreed they will visit.
- If the holes are historic and the timber is dry and sound, do not pay for a spray as a precaution.
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
Can dust fall out of old holes years later?
Old dust can be knocked out. Fresh dust is typically a brighter colour and keeps appearing. If you are unsure, say so rather than treating the house.
Does a guarantee from 1990 cover fresh dust today?
Only if the terms say so and the company still exists. A new emergence is a new question. Read the paper. Do not assume it.