Woodworm in buildings
The House Longhorn beetle measures up to 25 mm long when mature, and can lay up to 200 eggs on the rough surface of untreated timber. After 2-3 weeks, the larvae emerge and bore into the timber. They can be detected by the powdery deposits known as ‘frass’ left on the surface and the bore holes of around 3 mm diameter. They are attreacted to damp areas and timber with a high moisture content.
Other woodborer insects include:
- Furniture beetle: These are 6-8 mm long and lay 20-50 eggs on soft or hardwoods.
- Lyctus powder post beetle: These are 10-15 mm long and lap 70-200 eggs on the sapwood of new hardwood.
- Death Watch beetle: Around 7 mm long and lay 40-80 eggs on hardwood. Are a particular problem on oak timbers found in old churches and similar buildings.
Timber can be treated:by:
- A water-based boron treatment which can be sprayed or brushed on, or injected as a gel or paste.
- Ultraviolet insect killers.
- Fumigation or fogging.
- Replacing affected wood.
- Monitoring and improving conditions to prevent re-infestation.
 Find out more
 Related articles on Designing Buildings Wiki
- Ancient Woodland.
- Building preservation archive.
- Confederation of Timber Industries.
- Cross-laminated timber.
- Defects in construction.
- Domestic roofs.
- Dry rot fungus.
- European Union Timber Regulation.
- Flat roof defects.
- Flooring defects.
- Laminated veneer lumber LVL.
- Recognising wood rot and insect damage in buildings.
- Roofing defects.
- Timber framed buildings and fire.
- Timber preservation.
- Woodworm and spiders.
IHBC welcomes Gus Astley Student Award judge for 2018
Ingval Maxwell OBE, Chair of COTAC, past Technical Director at Historic Scotland, now Historic Environment Scotland, will judge the 2018 Awards and present them at AS2019.
IHBC HE & ALGAO LA conservation stats out now - 2018
LA conservation capacity in England: small annual increase follows years of conservation cuts. But still aggregates at 35% cuts over the last 12 years.
MHCLG is supporting building owners in taking immediate steps to ensure their residents’ safety and in making decisions on any remedial work that is necessary to do.