Timber Treatment & Wood Preservative

Common Furniture beetle

The most common form of woodworm beetle found in the UK is the common furniture beetle. (Anobium punctatum) is a wood boring beetle measuring 2.7-4.5mm in length.

This woodworm beetle attacks softwood species of timber leaving 1-2mm exit holes. It generally prefers damp, rather than dry wood and the grub will head for, and stays in, plywood for longer than any other timber.

Areas where the Common Furniture beetle are found

Damp floorboards, damp loft timbers, areas where there is a lack off ventilation ie sub floor areas and old furniture are good areas where the common furniture woodworm beetle can be found. The common furniture beetle lays its eggs on the timber and the grubs do the damage.

Death Watch beetle

The Death Watch beetle is a wood boring beetle approximately 7 mm long with larvae growing up to 11mm long.

To attract mates, these woodborers create a tapping or ticking sound that can be heard in old building rafters during quiet summer nights. They are therefore associated with quiet, sleepless nights and are named for the vigil (watch) keeping beside the dying or dead with the superstitious therefore naming it the Death Watch beetle.

The Death Watch woodworm beetle much prefers very damp conditions which are improved when there is some kind of fungal decay.

Areas where the Death Watch beetle are found

Virtually absent in Scotland, the Death Watch beetle prefers European hardwoods, especially oak, ash and chestnut; that have been “softened” the larvae tend to tunnel towards the centre of the timber resulting in damage that may be more extensive than is apparent from the exterior. In the UK, this species is concentrated mainly in southern/central England.

Dry Rot and its Control

Dry rot (Serpula lacrymans) is a wood-destroying fungus that are found in most parts of the world. Although it affects forest timbers, dry rot is best known for its ability to destroy timbers in ships and buildings.

Identification of Dry Rot

It is important to identify whether timber decay has been caused by dry rot or another wood-destroying fungus such as one of the wet rots. This is because dry rot has the ability to travel through building materials other than timber, giving outbreaks the potential to spread quickly through a building. For this reason additional measures (e.g. masonry sterilisation) often have to be taken when treating dry rot outbreaks over and above those necessary when dealing with outbreaks of other wood-rotting fungi.

Typical indications of dry rot include

Wood shrinks, darkens and cracks in a ‘cuboidal’ manner

A silky grey to mushroom coloured skin frequently tinged with patches of lilac and yellow often develops under less humid conditions. This ‘skin’ can be peeled like a mushroom.

White, fluffy ‘cotton wool’ mycelium develops under humid conditions. ‘Teardrops’ may develop on the growth.

Strands develop in the mycelium; these are brittle and when dry and crack when bent.

Fruiting bodies are a soft, fleshy pancake or bracket with an orange-ochre surface.

The surface has wide pores.

Rust red coloured spore dust frequently seen around fruiting bodies.

Active decay produces a musty, damp odour.

Important Note: Dry rot can cause widespread structural damage.

Dry Rot Control and Treatment

Dry rot will only affect timber that is damp, typically affecting timber with a moisture content in excess of 20%. For this reason, removing the source of moisture should form the core of any dry rot eradication strategy.

Timber can become damp for a number of reasons. Among the most common causes are leaking washing machines, shower trays, baths, The dampness can also come from outside the building, for example, leaking roofs, rising dampness, or dampness penetrating through walls.

However, it is not always possible or practical to be sure that the timbers will remain dry in the long term. Therefore, it is important that secondary measures are taken to defend against re-infection. Any affected timbers should be removed and replaced with pre-treated timber. Any remaining timbers at risk of being affected by the dry rot should be treated with an effective fungicide. Where the dry rot has passed through the masonry, it should be isolated using physical containment and/or masonry sterilisation.

Deepkill timber paste are particularly suitable fungicides for the treatment of dry rot, as they are able to spread much more deeply into the timber than conventional preservatives.

Wet Rot

While each fungus has its own unique features, the general appearance of wet rot is similar – as is the treatment. Wet rot is typically confined to the area of dampness because the mycelium does not spread into walls.

Wet rot is not as destructive as dry rot, however can and does cause structural damage.

Signs of Wet Rot in timber floors

Wet Rot decay is usually first identified when floor timbers start to bounce or have movement.

Skirting boards affected show signs of cracking even through paint. The unpainted unprotected rear of a skirting board will be more vulnerable to wet rot decay.