Discovering woodworm in a property during a survey causes understandable concern, but it is one of the more manageable defects found in older UK homes. Understanding whether the infestation is active or historic, and what treatment involves, helps buyers make an informed decision about whether to proceed.

What Woodworm Is

Woodworm is the larval stage of various species of wood-boring beetles, most commonly the common furniture beetle (Anobium punctatum) in UK residential properties. The larvae bore tunnels through timber over a period of several years before emerging as adult beetles through small flight holes. The presence of small round holes with fresh bore dust indicates active infestation. Old holes with no fresh dust indicate historic infestation that may be long dormant.

Active vs Inactive Infestation

The critical question is whether the woodworm is currently active. Active infestation produces fresh bore dust, sometimes called frass, around the flight holes, particularly during spring and early summer when adult beetles emerge. Inactive infestation, which is extremely common in old oak and pine timbers in older properties, means the beetles have moved on or the infestation died out years ago and the timber is no longer at risk.

A specialist timber survey by a qualified company such as a member of the Property Care Association can distinguish between active and historic infestation and assess the structural impact of any damage that has occurred. Many building surveyors will recommend such a specialist survey when woodworm is noted in the main survey report.

Structural Impact

In most cases, woodworm damage in residential properties is cosmetic rather than structural. The common furniture beetle tends to infest surface timber such as floorboards, joinery, and furniture rather than the deeper structural timbers that bear load. However, in cases of severe long-term infestation, structural timber can be weakened to a significant degree. The specialist survey assesses whether any structural timbers are compromised.

Treatment

Active woodworm is treated by applying a permethrin-based insecticide treatment to the affected timber surfaces. The treatment penetrates the timber and kills larvae within it. Most timber treatment companies provide a guarantee of ten to twenty years for the work. The cost of treating a typical property with limited woodworm in floorboards and joinery is typically five hundred to two thousand pounds, depending on the extent of the affected area.

Summary

Woodworm is common in older properties and is frequently historic and inactive. A specialist timber survey confirms whether the infestation is active and assesses any structural impact. Active woodworm treatment is straightforward and inexpensive relative to the property value. Historic inactive woodworm in older properties is rarely a reason to decline a purchase. The cost of treatment should be factored into the purchase price negotiation where active infestation is confirmed.