Timber Pests Other Than Termites

Borers

Borers of seasoned timber are generally beetles. The adult stage lays eggs, which hatch into larvae. The larval stage causes the damage by burrowing through and consuming the timber. The larvae pupate, then cut out through the timber when adult, in order to start the life cycle again. It is normally the cutting out process which is the first sign of borer infestation.

Hardwood borers

The borer which commonly attacks hardwoods is known as “The Powderpost Beetle” (Lyctus brunneus).

These borers only attack the sapwood areas of hardwoods and normally within the first 12 months of service. They only lay eggs in this region because the female’s ovipositor fits into the xylem vessels of hardwoods, which are a large vessel found only in the pore structure of hardwoods.

The “Timber Marketing Act” limits the amount of sapwood that can be present in hardwood timbers, and ranges from 25% in structural members to 0% in finishing elements. A time span of 24 months exists for the consumer to take action against the supplier, builder, and retailer. The Act is administered in Queensland by the Department of Primary Industries. Most of the time, no action is necessary when these borers or their damage is located, however it is always wise to have it inspected by a specialist.

Softwood borers

Borers which attack softwoods in Queensland are normally either “The Furniture Beetle (Anobium punctatum) or “The Queensland Pine Beetle” (Calymmaderus incisus).

These borers normally only attack certain softwood species which have been in service for 20 years or more, and can re-infest. Their damage is often found in floorboards and v-j wall linings, and has the appearance of squiggly lines on the top surfaces, and emergence holes of 1 – 2 mm diameter on the underside.

The infestation can be chemically treated annually for a 3 year period (which breaks the life cycle); however the long term solution is to replace the timber with a non-susceptible variety.

Other borers

As always, Mother Nature throws us curve balls, and there are many other borer species that can cause problems.

The “European House Borer” (Hylotrupes bajulus) can cause devastating damage, and an infestation of this beetle initiates the involvement of Government Authorities including the Quarantine Department.

In addition, green timber borers can be introduced to houses when buying timber articles. For example “Longicorn Beetles” can pupate in a state of suspended animation for some time, and so if someone buys a timber bowl and the adult beetle emerges, it can cut out through the article and the furniture it is placed upon, but will not re-infest any seasoned timber.

The identification of borer damage and the species that caused it is a specialist job which needs to be conducted by an adequately licensed inspector. It is sometimes very difficult to establish the difference between an active infestation and old damage.

Chemical Delignification

This is a condition where the organic glues “Lignin” which bond the wood cells together is broken down.

The timber takes on a soft, fibrous, hairy appearance, and is normally caused by an atmospheric condition. Therefore delignification is commonly found in buildings close to the seaside or industrial areas. It is normally a slow process which can take many years before the timber will collapse.

There is no chemical solution to stop this condition, and therefore timber replacement is the only suitable option.

Fungal Decay

Fungal decay or “Rot” is caused by a combination of water and fungal spores.

When we season timber, we dry it out, but it always wants to return to its original moisture content and will readily absorb accessible moisture. Once the timber exceeds 25% equilibrium moisture content, the fungal spores floating in the atmosphere, will attack the cell walls of the timber, causing it to breakdown and in a lot of cases collapse.

There are many types of decay fungi, and true identification of the species is a specialist job.

Generally the decay (whether decayed or decaying) is solved by identifying the source of the moisture and eliminating it, followed by replacement of the affected timbers with sound seasoned timber. It is obviously important to consider the type of timber and the purpose of use, when making a selection.

Subterranean Termites are often drawn to decaying timber, which is why it is important to renew shower sealants and the like. In our inspections, we use a moisture detection meter to confirm the presence of excessive dampness.

There are also various associated issues, such as toxic mould, which is a situation which requires inspection by a toxic mould specialist.