Woodworm

Woodworm is a common problem that affects thousands of homes, commercial properties and historic buildings across the UK every year.

If left untreated woodworm infestations can cause damage to all manner of timbers, including structural joists and beams, wooden furniture, wickerwork and even flooring and skirting boards. Woodworm prefer to infest the pale sapwood band of wood rather than the more resinous heartwood and if the timber is also damp, this will lead to more extensive damage.

Rentokil Property Care have put together a guide on woodworm, providing you with expert advice on how to deal with a woodboring beetle problem in your property.

We have been dealing with woodworm infestations in homes and businesses for decades, and have a number of CSRT and CSTDB qualified surveyors who are experts in identifying woodworm, and will provide you with detailed recommendations for treatments, if required. We are Property Care Association Members and have a number of branches across the United Kingdom, meaning we have qualified and experienced surveyors and technicians local to you.

Woodworm is a general term for the larval stage of various wood boring beetles that tunnel through timber. As the woodworm larvae feed on the wood they can cause significant structural damage. As the grown beetles emerge from the timber to continue the life cycle they can be identified by small exit holes they make and a fine powdery dust known as frass, which are the dried larval droppings.

It is the woodworm larvae that cause the most destruction as they consume the cellulose, hemicellulose and nitrogen in the wood, with the tunnels created causing structural weakness. This can cause severe damage to furniture, flooring, joists and beams, while leaving aesthetic damage in the form of small round holes. Old plywood is particularly susceptible to attack, as it contains animal based glues high in nitrogen.

Because there are several types of woodboring beetle, with varying levels of damage because of the size of tunnelling, correct identification is crucial.

Woodworm larvae are usually a creamy-white colour with a darker head, but are often hard to spot as they live inside the wood, with the adult beetle emerging when fully grown. If larvae are found on the surface of wood, they are unlikely to be woodboring beetles, but fly, moth or stored product beetle larvae.

The adult beetle will typically emerge between April and September, and are visible with the naked eye. Adult beetles vary in size, colour and shape, but are usually browny black and have wing covers (known as elytra) and are often noticed on window sills as they fly towards the sunlight.

The most common type of woodworm in the UK is the Common furniture beetle. This woodboring beetle is chocolate brown, has wings hidden under protective wing cases and is around three to five millimetres in size.

Other species of woodworm have identifying features, while the extent of the damage will vary depending on the size of tunnelling and length of life cycle. Because larvae are hidden inside the timber most of the year, it is more likely you will spot the signs of woodworm damage, rather than the beetles themselves.

Yes, woodworm is one of the most common issues that affects older untreated timber inside homes, historic properties and listed buildings across the United Kingdom every year.

Woodworm damage can often go unnoticed throughout the year as the larvae remain hidden inside timber, before emerging in the spring and summer. This is when woodworm can be spotted, as they leave behind small emergence holes and sawdust-like powder called frass.

The Common furniture Beetle (Anobium punctatum) is the most common type of wood boring beetle in the UK, which accounts for over 80% of all beetle damage in homes.

The woodworm life cycle has four distinct stages, egg, larva, pupa and emergence as an adult beetle. The life cycle can vary in length depending on the species of woodworm involved, but all will have the same four distinct stages. The Common furniture beetle lifecycle, which is the most common wood boring beetle in the UK, is between three and five years.

There are various reasons why a woodworm infestation may occur, including the accessibility of certain types of timber, the species of woodboring insect and the condition of the wood involved. But all the common woodborers occur naturally in the wild, particularly in decaying timber. If you are unsure if timber in your property is affected by woodworm, a damp and timber survey from a professional surveyor can help provide answers.

Some species of woodworm will attack softwoods such as pine, while others will target hardwood such as oak. Accounting for 80% of all woodworm damage in the UK, the Common furniture beetle will only eat the sapwood (the younger outer layer of wood) and leave heartwood (the more dense central core), unless it is wet or decayed. This is because the sapwood is 'soft' and  contains the nutrients required for growth, whilst the heartwood is dense and resinous.

Generally wood with a higher moisture content is more susceptible to a woodworm infestation. This is why timber in sub floors and cellars is particularly at risk from both fungal decay and insect attack. Eggs laid by the adult Common Furniture beetle will not hatch if the timber moisture content is lower than 8%.

Some types of woodworm require an even higher moisture content and in decayed timber. The Woodboring weevil is often found in structural timber decaying because of a damp problem.

Dry timber in a property will make it harder for the larvae to hatch and feed. This is because it is not possible for woodworm larva to drink from a source of water, so all the moisture they require for survival comes from the wood they digest. This means that in general, the damper the timber the more likely there will be a woodworm infestation.

The temperature will also impact the likelihood of a woodworm infestation, regardless of moisture content. Common furniture beetle larvae will thrive in temperatures between 22c and 23.5c, but can infest timber with a temperature between 12c to 29c.

The adult beetles will not lay eggs on varnished or painted timber, or bore into it, as eggs are left exposed on the surface and cannot be fixed in position. If however the timber is already infested below the surface, the woodworm will continue to cause damage and emerge through the painted or varnished surface.

This means that painting over a surface will not prevent emergence. In order to treat painted timber, the paint must be stripped and removed to allow insecticide to cover the surface.

Woodworm are most likely to infest timber that is unprotected and untreated. This is why it is common in older properties with untreated timber throughout. When timber surfaces are rough, this provides the perfect conditions for the adult females to lay their eggs.

There are many factors that affect suitability for infestation and whilst 'fresh' timber often appears unsuitable, infestations do occur, particularly if already infested items are close by.

Often woodworm larvae are inside a wooden item that is brought into a property, and over time can spread to other surfaces. This is common when buying antique or second hand furniture. This may go unnoticed for years, due to the woodworm lifecycle.

Woodworm can infest all manner of wooden items, from tool handles to rocking horses. It is important to check old wooden items for holes, especially the ply backs of wardrobes, wickerwork and wooden items stored in lofts. In the past, many loft infestations were started by placing removal companies' tea chests in lofts or items no longer suitable for the new home.

Often woodworm larvae are inside a wooden item that is brought into a property, and over time can spread to other surfaces. This is common when buying antique or second hand furniture. This may go unnoticed for years, due to the woodworm lifecycle.

Woodworm can infest all manner of wooden items, from tool handles to rocking horses. It is important to check old wooden items for holes, especially the ply backs of wardrobes, wickerwork and wooden items stored in lofts. In the past, many loft infestations were started by placing removal companies' tea chests in lofts or items no longer suitable for the new home.

Woodworm can get into a house in various ways, but one of the most common ways is adult beetles flying or crawling between buildings and then laying eggs on timber surfaces. This is because most woodboring beetles are found naturally in the environment or infested properties are next to each other, as may be found in a terrace.

Common furniture beetles, which are the most common cause of woodworm damage in the UK, are often found in old stumps in hedgerows. They are able to then fly into the home, especially during the summer months when windows are left open.

Another common infection route is when infested wood is brought into the home when bringing in old furniture, reclaimed timber and even firewood. Items stored in the attic, particularly after moving house, can introduce a woodworm infestation, which can spread to the roof timbers. Second hand furniture and antiques are another common method of woodworm infestations entering properties.

If you notice the signs of woodworm in your property, and are concerned about a woodworm problem, Rentokil Property Care can provide you with a detailed and thorough timber survey, providing you with answers on whether the infestation is active, and if specialist treatments are required.

A woodworm survey, sometimes referred to as a damp and timber survey, is carried out by a CSRT or CSTDB qualified surveyor, and is used to confirm woodworm activity, and the type of species involved.

The surveyor will carry out a thorough inspection of timber to understand the extent of the woodworm issue, and will confirm whether or not insecticidal treatments and timber repairs are required. A detailed inspection of a suspected woodworm infestation is crucial as different beetles may require different treatments, and the problem can often be hidden from sight.  In most cases, our surveyor will need to lift floorboards or access roof voids to fully investigate the affected area.

Any areas where access was not possible, such as under timber or vinyl laminate flooring will be listed for future inspection if access can be provided.

The surveyor will provide you with an easy to understand survey report, outlining the findings, and recommendations for treatments, if required. Rentokil Property Care have a number of PCA qualified surveyors who can help provide you with answers and long term solutions.

Rentokil Property Care are experts in woodworm and timber infestations, and have been offering professional solutions for decades.  We provide help to homeowners, social housing providers and commercial clients across the country with personalised advice for woodworm infestations.