Fight Woodworm Effectively - Guide Explains Best Practices

Fight Woodworm Effectively - Guide Explains Best Practices

the essentials in brief

  • Woodworms infest both old and new, moving or stationary, but above all built-up wood
  • An infestation can be recognized by the sawdust at the feet of the infested wood and by nibbling noises
  • Woodworms can be combated in an environmentally friendly way with strong heat (over 55 ° C), strong cold (below -12 ° C) or vinegar, ammonia or isopropanol
  • Pesticides should only be used in an absolute emergency

Which places are at risk?

Woodworms primarily target built-up, processed wood in order to lay their eggs in it. The pests do not care how old the infected piece of wood is. The new sauna is not spared, nor is a valuable antique. Against this background, it is not very reassuring that Hausbuck and colleagues generally spurn fresh tree wood in gardens, parks and forests. In and around the house there is a wide range of veritable places for the voracious rabble. The following table lists typical places where you can expect woodworm infestation:

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FurnitureRoof truss / roof beams
Parquet / plank floorBarn, garden shed
PanelingFirewood / firewood
Room beamsfront door
Living room doorWindow frames
Picture Frame
fighting wood worms

The woodworm doesn't care if you use a piece of furniture every day. As long as the table, chair, cupboard or chest of drawers are made of wood, cheeky female beetles can misuse all furniture as a breeding ground for insatiable larvae. Antique furnishings made of wood are just as unsafe against wood pests as recently purchased furniture directly from the carpenter's workshop.

Detect active infestation

Before investing a lot of time, effort, and money in combating it, make sure that it is an active woodworm infestation. Tiny holes in the wood are only an indication that maggots have been in it at some point. How to determine an acute presence of wood pests:

  • Pile of sawdust : lay out dark paper and check for fresh sawdust
  • Eating noises : pay attention to audible gnawing noises at night
  • Beetles : keep an eye out for live or dead beetles
  • Gnawed foil : cover wooden holes with foil in spring and inspect for gnawed exit holes until autumn
  • Expert opinion : commission a certified expert before starting cost-intensive control methods

If there are no doubts about an active infestation based on the evidence, please consider the further procedure. There is seldom any urgent need to take control measures against woodworms. Experience has shown that the woodworm pushes its destructive work leisurely but unstoppably. For this reason there is no reason for blind actionism, such as using the chemical club or digging deep into your wallet. In the early stages or in the event of local infestation, there are tried and tested options to combat the pests yourself with natural means.

fighting wood worms

Fight woodworms without toxins - means and methods at a glance

The invasive destructive power in the immediate living environment of the family makes fighting the house longhorn, rodent beetle and cronies a difficult undertaking. This is where the plausible desire for non-toxic methods meets a die-hard pest with a clever survival strategy. The following table provides an overview of biological agents and methods that effectively combat wood pests:

Home remediesHeat above 55 °Cold below - 12 °mechanical methods
Vinegar / vinegar essencesaunaCooling chamberAcorns
Ammoniamicrowaveoutside (in winter)Compressed air
Hot air / hairdryervacuum
Drying chamber (carpenter's workshop)
Foil hood (outside)

Home remedies versus woodworm - tips & tricks

Local infestation favors woodworm control with natural means. The focus is on tried and tested home remedies, which the above table names. In the following, we have put together some promising tips for successful use:

  • Isopropanol : apply with a paintbrush, pack airtight in foil, leave to work for 3 to 5 days
  • Vinegar : Pour vinegar essence into syringe and spray into each woodworm hole
  • Salmiak spirit : put on breathing protection, put wood with open salmiak spirit under a foil hood for several hours in the sun

The use of home remedies should not be taken lightly. Please pay attention to important safety precautions. There is an increased risk of fire when using high-percentage isopropanol. Vinegar essence can damage wooden surfaces. Vapors from ammonia are not only harmful to health, they often change the color of the treated wood. Alcohol may act as a solvent. Test in advance in a hidden place that the wooden surface does not show any negative reactions to the biological agent.


A double-edged sword in fighting wood pests are biological agents with an intense odor. Tea tree oil, linseed oil, gasoline, diesel or kerosene achieve very good results in order to scare away or destroy the woodworm, never to be seen again. The joy of victory is short-lived, because you will struggle for years with a persistent stench.

Thermal combat - instructions for laypeople

fighting wood worms

The woodworm is terrified of the heat and cold. In fact, the insatiable larvae have nothing to withstand the heat or freezing frost. Unless the infestation is extensive, thermal control of wood pests is very popular because it works without poison and appropriate equipment is usually available. This is how thermal woodworm destruction works:

  • Oven : Heat the wood slowly at 60 degrees and let it cool down overnight
  • Sauna : gradually heat large pieces of wood to 60 degrees and slowly cool down
  • Microwave : Microwave small parts several times for 90 seconds at 600 watts
  • Drying chamber : Let mobile furniture heat up in the drying chamber at a carpenter's or a sawmill
  • Freezer : Wrap wood in foil and place in the freezer for 2-3 days
  • outside : expose worm-eaten wood under a foil hood to the cold in winter

The microwave method also promises good results with large-scale woodworm infestation. Of course, for use on large pieces of furniture, thick beams or the entire roof structure, different calibres are required than the microwave in your kitchen. With the help of special emitters, shaped like a megaphone, the wood is bombarded with microwaves in sections. Holzbock and other wood pests do not withstand this treatment for long. The associated risks, such as overheating, risk of fire or cracks, require many years of experience, which certified exterminators and a reputable specialist company have to offer.

Non-toxic hot air process

Woodworms get upset with hot air when the outflowing air is more than 55 degrees Celsius. The hot air process has emerged as one of the best methods to combat woodworms safely and without toxins. Affected areas and areas are sealed off with tarpaulins, apart from a controlled ventilation opening. External hot air blowers heat the wood for a period of 8 to 14 hours and destroy all insect pests in it.

You can achieve the effect locally with a hair dryer. The cost-benefit effect is of course assessed critically. The power-guzzling device should be activated for at least 45 minutes, which drives up the next electricity bill. Furthermore, the air flow is directed to a very narrow radius, so that a complete destruction of all maggots is pure luck.

The woodworm only lives as long as the maggot does in bacon until the wood is heated, frozen or soaked in alcohol.

Getting rid of woodworm mechanically

The effectiveness of home remedies and thermal methods is optimized with complementary, mechanical strategies. The motto is: with carrot and stick. By permanent row you make the beasts life hell. At the same time, you offer the larvae a tempting treat as a retreat outside of the wood. This is how the plan works:

  1. Place acorns around the infested wood
  2. From now on, knock the wood vigorously at every opportunity
  3. Replace acorns with feeding holes for fresh fruit every 2 to 3 days
  4. Dispose of acorns colonized with woodworm on the compost
  5. Continue until no more acorns have been drilled through

Woodworm larvae have cracked and don't always fall for the knocking acorn trick. If the results remain far below expectations, compressed air technology can be used as a further mechanical approach. For this purpose, blow out each feeding tunnel with compressed air from the round entrance. Since you cannot see inside the wood, with the compressed air method you can never be sure that you have caught all the vandals.

Last resort pesticide

If all efforts to combat biological control come to nothing, the chemical club awaits at the end of the tunnel. The specialist trade offers numerous pesticides that kill woodworm larvae. The other side of the coin are toxic ingredients such as permethrin. It is a neurotoxin that is harmful to humans and pets. Important safety precautions must be observed in advance, which each manufacturer explains in detail in the instruction leaflet. The following products are rated as effective by woodworm-plagued users:

  • Envira woodworm spray at a price of 11.80 euros for 500 ml
  • Kluthe Holzwurmtod at a price of 17.99 euros for 2.5 l plus 5 disposable syringes at a price of 8.95 euros
  • Xyladecor against woodworms with a spray head at a price of 11.50 euros for 250 ml
  • Woodworm stop with injection attachment from Detia Garda at a price of 9.90 euros for 200 ml

The undisputed test winner is the woodworm spray from Envira. The agent is not caustic, odorless and non-flammable. The knock-down effect on the woodworm is primarily based on the ingredient permethrin. For large-scale use, the manufacturer offers inexpensive refill packs with 2 or 5 liters.

Entrust large-scale control to specialists

If the roof structure or load-bearing parts of the building are contaminated with woodworms, you should refrain from doing this yourself. Extensive self-control is associated with incalculable risks and is rarely crowned with success. Instead, rely on the experience of experienced and certified experts, because after all, it's about your home.


Chemical fumigation is the subject of criticism

As an alternative to the hot air process, specialist companies offer the option of fumigating infested roof trusses, apartments and houses with a special poison, usually sulfuryl fluoride or a mixture of sulfur and fluorine. This gas reliably destroys all wood pests and works without depot effect, so that treated rooms can usually be used again after 24 hours. The comparatively high cost factor is to be rated as disadvantageous, due to complex preparations. Furthermore, special technology is used that requires well-founded know-how. Last but not least, the prospect of a life in a toxic fumigated house leaves many people with a queasy feeling.

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Woodworm is a beetle larva

The term woodworm functions as a synonym for a whole flock of airworthy beetles and their larvae. If tiny holes in the wood of roof trusses, furniture or beams cause headaches, you are not dealing with a worm infestation. Rather, you are confronted with the destructive brood of the following types of beetles, which eat their way through the wood in the form of cylindrical maggots:

  • Longhorn beetle, primarily house longhorn beetle (Hylotrupes bajulus): 8-26 mm long, winged, hairy brown to black and gray
  • Common rodent beetle (Anobium punctatum): 2-5 mm long, winged, reddish-brown, very hairy, hooded pronotum
  • Colorful pound beetle (Xestobium rufovillosum): 5-7 mm long, winged, dark brown with yellow hair spots
  • Defiant head (Hadrobregmus pertinax): 4.5-6 mm long, winged, black-brown, cylindrical, sparsely hairy
  • Brown sapwood beetle (Lyctus brunneus): 2.5-7 mm long, winged, red-brown, smooth, dotted elytra

Maggots of these beetles can hardly be distinguished by species for laypeople, because the color of the worm-shaped body is uniformly white to cream. In the course of several larval stages, house longhorn beetle larvae reach up to 30 mm in length, whereas rodent beetle larvae rarely grow longer than 5 mm.

Way of life

fighting wood worms

A female beetle lays up to 200 eggs per year - depending on the species - in the wood and then leaves the brood to its own devices. Within a short period of time, the eggs transform into insatiable larvae that bore their way through the beams, parquet, furniture or otherwise processed wood. Up to eight years pass before the larvae of the common rodent beetle pupate. The larvae of the house billy goat can be up to 15 years. Only then does the metamorphosis into an adult beetle take place. On the way there, an extensive system of feeding tunnels is created, which significantly impairs the stability in the wood and in the worst case causes entire roof structures to collapse. The life span of a finished beetle extends over a few weeks during which no food is consumed.

This short excursion into the biological background of woodworm species does not claim to be of scientific quality or completeness. Various Wikipedia articles provide comprehensive information about the woodworm.


Do not confuse the house trestle with the wooden trestle

The naming of two completely different insects harbors a high risk of confusion, which can have fatal consequences. Under the name Hausbock, a longhorn beetle (Hylotrupes bajulus) spreads fear and horror in Europe, which is also known as the large woodworm or beam beetle. This guide is dedicated to effective control of these wood pests. The name Holzbock (Ixodes ricinus), on the other hand, hides one of the most dangerous types of ticks, which can cause considerable damage to people and pets. A mix-up of the two terms should be ruled out beforehand when choosing pesticides, because most anti-house buck remedies are ineffective against the wood buck and vice versa.

frequently asked Questions

What costs are to be expected if an exterminator is hired to combat woodworms?

Estimating the costs of using a specialist company in advance is difficult or even impossible. Numerous factors determine the final price, such as infestation location, type of pest, infestation pressure, control method and time used. A reputable company first inspects the property and then creates a cost calculation. As a rough guide for the hourly wage, 100 to 150 euros can be expected. The killing of wood pests in built-in wood using non-toxic microwave or hot air methods costs an average of 600 euros.

Where can I buy agents for woodworm control?

Biological agents such as isopropanol or ammonia are available from hardware stores, for example from Obi, Toom or Hornbach. The range also includes insecticides, such as the test winner Envira Holzwurmtod or the tried and tested wood preservative Xyladecor for protective exterior paintwork.

My old chest of drawers is infected with woodworms. I've heard that the cold kills the pests. Is it enough to put the old furniture on the balcony when it is frosty?

Fighting woodworms with cold requires that you expose the infected chest of drawers to frost below -12 degrees Celsius for 48 to 72 hours without interruption. In Germany, this premise cannot be met in most regions, as temperatures exceed the threshold value at least during the day. If the balcony is in a winter-gray Alpine region or in the Ore Mountains, it is at least worth a try.

I read on the Internet that the woodworm can be fought with nitrogen without poison. Can I use the method to fight the pests in a living space myself?

Fumigation with nitrogen works on the principle of asphyxiation to kill the woodworm. For this purpose, infected wooden objects or an affected living space must be enclosed in a gastight manner with foil so that no oxygen can penetrate. Constant temperatures above 20 degrees Celsius and a treatment duration of 8 to 10 weeks are decisive for the success of the control. During this time nobody is allowed to approach the apartment within 10 meters without special protective equipment. The control method is only allowed to certified specialist companies throughout Europe.

Fight woodworms with hairspray - is that possible?

In one or the other forum you can read that hairspray is good as a home remedy for woodworms. Theoretically, the spray could clog the maggots' sensitive respiratory organs, causing them to suffocate. In this context, it is underestimated that these are clever pests that eat their way deep into the wood - inaccessible to non-toxic hairspray. Effective woodworm spray has poisonous components in its luggage and is not only sprayed on the surface. Commercially available products have an injection attachment so that the insecticide can be delivered deep into the feeding tunnels.

Where can I find the contact details of certified woodworm control professionals?

The Deutsche Holz- und Bautenschutzverband eV operates an informative database which you can use to find a qualified company for combating wood pests in your area. Based on your postcode, an intuitive search mask will guide you step by step to the contact details. As a rule, there are several DHBV specialist companies to choose from.


In a vacuum, the woodworm runs out of air after four to twelve weeks at the latest. In order to free valuable antiques or irreplaceable family heirlooms from wood pests without poison, specialist companies offer temporary or permanent storage in a virtually vacuum. The method also works on its own for handy, small furniture, provided the infected part fits into a vacuum bag measuring 180x90x50 cm and a vacuum sealer is available.