Woodworm is the generic term that applies to the wood-eating larva of many species of beetle. It is also the description given to the infestation of wood by these larvae.
Uncontrolled insect infestation can be devastating within the home. The visible signs of woodworm are small holes in the timber, that result from the emergence of the adult beetles. If there is powder (or frass) beneath the hole, then the beetles are likely to be fresh and alive, and will require treatment.
The eggs are laid just beneath the surface of the wood and, when the grubs hatch, they eat their surroundings. After pupation, the adult beetle emerges at the surface of the wood and the cycle begins again.
The insects need similar conditions and characteristics to wet and dry rot. The larvae particularly thrive in damp timbers and the hatched larvae are attracted to the starches and sugars contained in the wood, just like a fungus.
The following is a list of the most common insects to cause this type of issue in Britain’s homes.
Common Furniture Beetle
A small dark reddish-brown beetle, damage caused by these insects is the most commonly found. The beetles attack the sapwood within European hardwoods and various softwoods, and outbreaks are considerably more severe in damp timber.
Deathwatch Beetle
These are chocolate brown and focus mostly on hardwoods, like Oak. They are commonly found during the emergence period, which spans from mid-March to the end of June, and can have patches of yellow hair. Softwood is not entirely safe from these beetles, though – rotted timbers can be susceptible, particularly if in contact with hardwood.
Powder Post Beetle
Similar to the common furniture beetle, these are differentiated by requiring a high starch content in the timber which can be influenced by methods of handling and storing logs or of drying after conversion.
House Longhorn Beetle
Characterised by their long antennae, these are large, brown to black beetles that are very localised to the South East of England, particularly around the Camberley area. They are not to be underestimated and can create dust-filled tunnels in bark and sapwood.
The solution
Dry timber is considered immune to attack, as is the case with dry rot and wet rot. The first port of call at an affected property is to reduce the timber moisture content to below 15%. Efforts will need to be directed towards increasing the ambient temperature of the timber using background heating and introducing additional ventilation. As most timber defects are found in the roof space, ventilation will perhaps be the most important of these.
Additional solutions include chemical treatment, heat treatment, pheromones and ultra-violet light.
As with any property defect, if you suspect your home has a woodworm infestation the best advice initially is to speak with an independent Chartered Surveyor. A remedial treatment contractor may be biased in his assessment rather than looking at any causative issues.
Your surveyor will advise you from a neutral, professional stand-point, and arm you with the information you need to remedy the problem safely and cost-effectively.