Woodworm in Your Home: What It Looks Like, What It Does, and When to Act

Most People Don't Notice Woodworm Until Real Damage Has Been Done

A few tiny holes in an old floorboard. A fine dusting of what looks like sawdust near a wooden beam. These are easy to dismiss as general wear and tear, especially in older properties. But those small signs are often woodworm, and ignoring them gives the infestation time to quietly hollow out the structural timber in your home.

Woodworm is one of the more misunderstood property problems out there. It's not actually a worm at all. The damage comes from wood-boring beetle larvae, which tunnel through timber while feeding, leaving behind a weakened structure and those telltale exit holes when they emerge as adults.

Which Beetles Are Actually Responsible

The Common Furniture Beetle is behind the majority of woodworm cases in UK homes. It tends to go after softwoods and the sapwood of hardwoods, which covers a lot of household timber including joists, floorboards, roof timbers and furniture.

Two other species worth knowing about are the House Longhorn Beetle and the Deathwatch Beetle. The House Longhorn is less common but causes significantly more damage — its larvae are larger and can compromise structural roof timbers faster. The Deathwatch Beetle tends to target older, hardwood timbers, often in historic buildings. Both are worth taking seriously if you spot signs of them.

How to Tell If an Infestation Is Still Active

This is the question most homeowners get wrong. Seeing exit holes in wood does not necessarily mean there's an active problem. Those holes could be from an old infestation that's already run its course.

The real indicator of active woodworm is fresh frass — the fine, powdery dust that larvae produce as they eat through wood. It's a creamy or yellowish colour and tends to collect just below the exit holes.

You might also spot it on surfaces beneath affected timber. If the frass looks fresh rather than compacted and old, there's a good chance the larvae are still active.

Spring and early summer are the peak emergence period for adult beetles, so if you're seeing live beetles near wooden surfaces during those months, that's a clear sign something is going on.

Where to Check in Your Property

Woodworm thrives in damp, poorly ventilated timber. That makes certain areas of a property more vulnerable than others.

• Roof timbers and loft spaces, particularly if there's any moisture getting in
• Subfloor joists and floorboards, especially in older homes with suspended timber floors
• Wooden staircases and balustrades
• Furniture made from untreated or older wood
• Outbuildings and garages with timber frames

Damp is a significant factor here. Timber that's already been affected by moisture is far more attractive to wood-boring beetles. If you have a damp problem alongside woodworm, dealing with only one of them is unlikely to solve the issue long-term.

Treatment Isn't Always a DIY Job

Over-the-counter woodworm treatments exist, but they work best when applied to accessible, unfinished timber with a confirmed active infestation. For structural timbers, or where the extent of the damage isn't clear, a professional survey makes sense before anything else. Treating the surface without understanding how deep the damage runs can give a false sense of security.

A proper assessment looks at the species involved, how widespread the infestation is, whether any timber has been structurally compromised, and whether damp is contributing. From there, treatment can be targeted rather than guesswork.

If you're in Richmond or the surrounding area and you've spotted the signs, getting eyes on it sooner rather than later means less timber to replace.