Post actualizado el día octubre 25, 2026 by DeiviSanzPlay
Watching your wooden furniture fill up with little holes and small piles of fine sawdust is one of those things that eats you up inside. Woodworm doesn’t go away on its own, and the longer you wait to act, the more expensive the fix becomes. I’ve been looking at what people who have actually dealt with this say, and I’ve tried (or ruled out) methods until I settled on the ones that really work. Here’s what works and what’s pure fiction.
What exactly is woodworm and why is it eating your furniture
Before you start spraying products, understand the enemy. Woodworm isn’t a bug you see scurrying around: what you hear is the larva eating wood from the inside. The adult is a small beetle, most often of the Anobiidae or Cerambycidae family, which lays eggs in the cracks and joints of the wood.
When those eggs hatch, the larva burrows inward and can spend months or even years gnawing before emerging. That’s why you see holes but not the culprit. The classic symptom of a woodworm infestation is the sawdust (the «frass») that appears under the furniture, and the rounded exit holes of 1 to 3 millimetres.
Detecting woodworm in time completely changes the cost of treatment. If you see an isolated hole, you can still save it yourself. If the furniture sounds hollow when you tap it, you’re already in another scenario.
Trick 1: controlled heat, the cleanest method there is
Heat is probably the most effective thing you can do at home without using poison. Woodworm larvae die when the wood reaches between 50 and 60 °C for at least 30 minutes straight. It’s not enough to heat the surface and be done: the inside of the plank has to reach that temperature.
For small objects, a heat gun of the kind used for stripping paint is perfect. For large pieces, things get complicated and it often works out cheaper to put the furniture in a professional thermal chamber, which is what woodworm treatment companies with a guarantee use.
A trick from people who do it right: use a laser thermometer to measure the temperature at various points, especially in corners and joints, which is where the larva hides. If you don’t reach a real 55 °C throughout the piece, you haven’t killed anything.
Watch out for direct sunlight in summer: I’ve seen furniture with the varnish ruined from leaving it «in the heat» without control. The idea is good, but careless execution ruins the piece.
Trick 2: essential oils, useful but not miraculous
Essential oils of cedar, lavender and orange have real repellent properties against woodworm. The key is in the word «repellent»: they drive away and make it harder for new females to lay eggs, but they don’t kill larvae that are already inside the wood.
The mixture that works best in practice is one part essential oil to ten parts water, with a splash of alcohol so they emulsify, applied with a spray bottle directly into the holes and joints. Repeat every two or three months, especially in spring and summer, which is when the adult beetle is active.
If you have small children or pets, this method is the safest of all the ones I’m going to tell you about. And it leaves a pleasant smell, which isn’t a small thing compared to conventional insecticides.
Trick 3: freezing, only for small pieces
Extreme cold also kills woodworm. The protocol is simple: you wrap the piece in plastic film or in a sealed bag, put it in the freezer at -18 °C and leave it there for at least 72 hours. That thermal shock disrupts the biological processes of larvae and eggs.
It’s an ideal method for frames, small carvings, instruments or museum pieces. But don’t try to freeze a door or a wardrobe. And very important: when you take it out, leave it wrapped while it returns to room temperature for 24 hours. If you uncover it while it’s still cold, condensation gets into the wood and you can cause cracks or damp stains worse than the woodworm itself.
Freezing as a treatment against woodworm works best combined with heat or with subsequent varnishing, never alone in active infestations.
Trick 4: varnishes and paints that seal the wood
Once you’ve killed what was inside, the next mandatory step is to seal. A good varnish or a paint specifically for wood creates a physical barrier that prevents the adult female from penetrating and depositing new eggs.
Choose the product according to the use of the furniture: for outdoors, varnishes with a UV filter; for indoors, any polyurethane or nitrocellulose one will do. Apply two or three thin coats, with a light sanding between coats, and pay special attention to the edges, borders and areas where there were already holes.
Typical mistake: varnishing before treating. If you do this, you seal the larvae inside and give them food for years. First you kill, then you protect. In that order.
Trick 5: when to call a woodworm control professional
There comes a point where insisting on home remedies is throwing money away. If the infestation affects beams, structures or several pieces of furniture at once, you need someone with products that aren’t sold to the public, such as professional-application insecticides with years of residual power.
A good technician doesn’t just fumigate: they make a diagnosis based on humidity and type of wood, tell you whether the holes need to be injected, whether high-power microwaves should be applied or whether it’s better to replace pieces. And they give you a written guarantee, which is what really makes the difference.
The price of a professional woodworm treatment usually ranges from 300 to 1,500 euros depending on square metres and severity, but it’s cheaper than replacing an antique piece of furniture or, worse, having to change the structure of a roof.
How to prevent woodworm from coming back to your home
Prevention is boring but it’s what really works. Woodworm looks for wood with humidity above 20 % and poorly ventilated environments, so the first thing is to control that: cross ventilation, no damp in basements or storage rooms, and checking the furniture twice a year.
When you buy second-hand furniture or antiques, inspect them before bringing them into the house. An infected piece of furniture can contaminate the whole room in a couple of seasons. And if you have valuable pieces, applying a preventive treatment with cedar oil every six months will save you some scares.
In the end, woodworm is fought like almost everything in life: with consistency. The five tricks I’ve told you about, used in the right order (detect, kill, seal, prevent and, if needed, professional), solve 90 % of cases. The other 10 % are structural infestations that require an expert hand, and there’s no way around it.
