Woodworm is a common issue in properties across the UK, particularly in older buildings where timber has been exposed to moisture over time. Left untreated, wood-boring insects can cause significant structural damage to floors, roof timbers, and furniture. As damp and timber specialists and members of the Property Care Association (PCA), we’re often asked how to identify woodworm and what steps homeowners should take if they suspect an infestation.
In this guide, we’ll explain what woodworm is, how to spot the signs, how serious it can become, and what the best treatment options are.
What Is Woodworm?
“Woodworm” is the general term used to describe the larvae of several species of wood-boring beetles. These larvae tunnel through timber as they feed, gradually weakening the structure from the inside.
The most common species found in UK homes include:
- Common Furniture Beetle (Anobium punctatum)
- Deathwatch Beetle (Xestobium rufovillosum)
- House Longhorn Beetle (Hylotrupes bajulus)
The larvae live inside timber for several years before emerging as adult beetles, leaving behind the small holes most people associate with woodworm.
Signs of Woodworm to Look Out For
Many infestations go unnoticed for years because the damage occurs inside the wood. However, there are several clear signs homeowners can watch for:
1. Small Round Exit Holes
The most obvious sign of woodworm is small round holes in timber surfaces. These are typically 1–2mm in diameter and are where adult beetles have emerged from the wood.
2. Fine Powdery Dust (Frass)
You may notice fine, powdery dust around holes or beneath affected timber. This material, known as frass, is produced as the larvae tunnel through the wood.
3. Weak or Crumbling Timber
Timber affected by woodworm may feel soft, brittle, or crumbly. In more severe cases, the surface may break away easily.
4. Tunnels in the Wood
If you split open damaged timber, you may see a network of tunnels where the larvae have been feeding.
5. Adult Beetles Appearing
Seeing small beetles emerging from timber, particularly between May and September, can indicate an active infestation.
How Bad Can Woodworm Get?
The severity of woodworm damage depends on the species of beetle, the age of the infestation, and the condition of the timber.
In mild cases, the damage may be superficial. However, in more advanced infestations, woodworm can weaken critical structural timbers such as:
- Floor joists
- Roof timbers
- Beams and lintels
- Staircases
- Floorboards
When timber becomes structurally compromised, it may require partial or full replacement. This is why early detection and professional assessment are so important.
Woodworm is also commonly linked to damp conditions, as many wood-boring beetles prefer timber with elevated moisture levels.