Timber decay and woodworm
Flight holes in a beam have no fresh dust under them. What can the survey not say about whether the beetle is still active?
The survey cannot say whether the beetle is still active. Flight holes with no fresh dust under them show old emergence, not insects seen at work on the day. Lack of dust is not proof they have gone, because dust can be cleaned away or fall where it was not looked for. It is also not proof they are active. No monitoring was done. The finding is holes without fresh dust. The survey has not declared the attack historic for certain, and it has not declared it live.
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?
Fresh dust, or frass, under flight holes is the usual sign that beetles have emerged recently. A clean sill under old holes fits an attack that may have died out when the timber dried. A single visit cannot watch a beam for a season, and it cannot know if someone brushed the dust before the inspection. The honest limit is that activity was not shown and extinction was not shown either. The holes remain. The life in them was not established.
If activity is the question you need answered, a timber specialist can look more closely and, where it is justified, monitor the beam rather than treat it on guesswork. Tell the solicitor the home survey has not confirmed live beetle and has not given the timber a clean bill. The survey has not specified a spray and has not specified replacement of the beam. Do not brush the holes or fill them before that look. Covering the evidence makes the next inspection harder.
What should you ask your surveyor?
- Did you see flight holes with no fresh dust, and no live insects?
- Have you left activity undecided rather than calling it historic?
- Was any monitoring done, or only this single look?
What are the typical next steps?
- Record holes without fresh dust, not a verdict on live beetle.
- Ask a timber specialist if this beam needs monitoring rather than treatment.
- Do not fill or brush the holes before that further look.
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
If the beam is painted, can dust still be judged?
Paint can hide both dust and the edges of holes. Where the survey could see holes and no fresh dust, that is all it could say. Paint does not let the survey decide whether the beetle is active. No later decision about the paintfilm was made, and this visit did not supply one.
Does no dust mean the wood is structurally sound?
No. Absence of fresh dust speaks to activity, not to section. The survey has not measured whether old attack has reduced the beam, and soundness was not decided by a clean surface underneath. What happens next for the sectionloss is outside this note and was not settled here.