Woodworm treatment should follow identification of the insect and evidence of current activity. Small holes in timber may record an old infestation rather than a problem that needs spraying today. A timber assessment helps distinguish those possibilities and determine an appropriate response.
What does woodworm look like?
Woodworm is a common name for the larvae of beetles that bore into timber. The larvae generally remain within the wood, so homeowners are more likely to notice exit holes, loose bore dust or an emerging adult beetle than the larva itself. Different insects leave different signs, and a hole alone does not identify the species.
Examine accessible surfaces without lifting boards or damaging a finish. Photograph holes beside a scale and record their location. Keep any insect found in a closed container for identification if you can do so safely. Avoid assuming every mark in an older floorboard is recent insect damage.
Signs of activity and the need for a survey
Fresh-looking dust near holes may prompt investigation, but disturbance can also release old material. A woodworm survey considers the timber, visible evidence, moisture conditions and whether activity is ongoing. It may be necessary to inspect more than the exposed surface to understand the extent.
For woodworm in floorboards, access below the floor can matter as much as the boards visible from above. Do not climb into unsafe spaces or pull up flooring yourself to search. If a floor feels weak, keep people away from the affected area and seek competent advice on its condition rather than testing it by jumping or probing.
How is woodworm treated?
The response depends on identification, current activity and the condition of the wood. Where treatment is justified, a suitable insecticidal product may be applied to accessible timber according to its authorised instructions. The choice of method also depends on coatings, access and the timber involved; indiscriminate spraying is not a substitute for diagnosis.
A competent contractor should explain preparation, application and any restrictions on use of the space. Product labels govern ventilation, protective equipment and re-entry. Keep occupants and pets out as instructed, and discuss sensitive belongings before application. Do not mix products or use an outdoor treatment inside the home.
Timber condition and moisture are separate checks
A treatment intended for insect activity does not restore strength to timber that is already badly damaged. The condition of load-bearing material needs competent assessment, with any repairs specified separately. That distinction matters when comparing quotations: applying a product and repairing a weakened element are different tasks.
Moisture conditions can also influence the suitability of timber for infestation. Ventilation, leaks and persistent damp deserve investigation where relevant. If walls or rooms are damp as well, Damp Pro and Co’s free homeowner damp survey can investigate the damp problem. Ask separately about arrangements for a timber assessment.
What affects woodworm treatment cost?
The amount and accessibility of timber, evidence of active infestation, preparation and the treatment selected all affect the work. Lifting and reinstating floor finishes can change access requirements, while damaged structural elements may require a separate repair recommendation. A written specification is more useful than a price based only on a photograph of holes.
Ask what the inspection covers, which timber is included and how the contractor established that treatment is needed. Check whether preparation, making good and any follow-up assessment are included. Keep the findings with the quotation so you can compare the same scope rather than different assumptions about the problem.
Before agreeing to treatment
Confirm which product and method are proposed, how finishes will be protected and when the space can be used again. Ask for advice specific to varnished, painted or bare timber, as coatings can affect access and the response of the surface. Where appearance matters, discuss an inconspicuous test and follow the product instructions.
Use the enquiry form to describe what you have found and ask about service availability before arranging woodworm treatment. Mention the location of holes, any new dust and whether the floor or timber feels damaged. For accompanying damp walls, the existing free damp survey offer provides a separate starting point.
Moisture-related timber decay needs a separate assessment: see dry rot treatment and wood rot repair.
For the existing homeowner damp assessment offer, see our free damp survey page.
Woodworm treatment questions
Can woodworm come back after treatment?
Further activity is possible if affected timber was inaccessible, the original problem was not properly identified or a new infestation occurs. Report fresh evidence and ask for reassessment rather than assuming old holes prove continuing activity.
Does woodworm treatment smell?
Odour depends on the product and application. Ask which product is proposed and follow its ventilation and re-entry instructions; a lack of smell does not establish that a space is ready to use.
Does woodworm treatment stain wood?
The effect depends on the product, timber and existing finish. Discuss surface compatibility and an inconspicuous test where appearance matters, following the manufacturer’s instructions.