Woodworm Treatment Spain: Products, Costs & Tips (2026)
Found flight holes or sawdust? How to treat woodworm in Spanish properties with products from Leroy Merlin and Amazon.es.
By James Thornton
You noticed small round holes in a wooden beam. Fine dust below the skirting board. A faint hollow sound when you tap the door frame.
In the UK, you’d immediately think: woodworm. In Spain, the locals call it carcoma — and if you’ve bought or are considering buying an older Spanish property, you need to know exactly what you’re dealing with and how to treat it.
The good news: most woodworm infestations in Spain are treatable, and the right products are readily available. The important news: structural beam infestations in old campo houses and fincas are a different matter — and getting the diagnosis right before you start is critical.
This guide covers everything expats need to know about woodworm treatment in Spain.
What Is Woodworm (Carcoma) in Spain?
“Woodworm” isn’t one species — it’s a shorthand for several wood-boring beetle species whose larvae eat timber from the inside out. In Spain, the most common culprits are:
Common furniture beetle (Anobium punctatum) — The classic woodworm. Affects furniture, floorboards, roof timbers, and any untreated or older wood. Its larvae spend 3–5 years eating their way through timber before emerging as adult beetles, leaving the characteristic 1–2mm round exit holes.
Death watch beetle (Xestobium rufovillosum) — Larger, more destructive. Prefers old hardwood — oak beams, structural timber in historic buildings. If you’ve bought a traditional Spanish townhouse with exposed wooden beams, this is the species to watch.
Bark borer (Ernobius mollis) — Attacks timber that still contains bark, common in rural constructions. Generally less destructive to structural integrity.
All three are present in Spain, and Spain’s climate — particularly the dry, warm interiors — suits them well.
Why Old Spanish Properties Are So Vulnerable to Woodworm
If you’ve bought a rural finca, a campo house, or an old pueblo property, there’s a specific risk profile you should understand.
Traditional Spanish rural construction relies heavily on exposed wooden beams — often pine or chestnut — that support bóveda (barrel-vaulted) ceilings. These ceilings are extremely heavy, especially where later renovations added thick tile floors and concrete screeds on top. The load-bearing capacity of those beams matters enormously.
The problem: untreated timber in old Spanish properties is a woodworm buffet. Many rural houses were built before modern wood preservation, and the warm, dry conditions that make Spain so attractive to humans also create perfect conditions for wood-boring beetles to complete their lifecycle.
A beam that looks solid may be extensively honeycombed inside. By the time you see sawdust on the floor, the larvae have been active for years. In severe cases, a beam that looks structurally fine externally has lost most of its load-bearing cross-section internally — and that’s a genuine safety issue.
This is why getting the diagnosis right matters more than rushing to grab a bottle of Xylazel.
How Do You Identify Woodworm in Your Spanish Home?
What Signs Should You Look For?
Exit holes — Small, round holes, 1–2mm in diameter for common furniture beetle, up to 3mm for death watch beetle. These are NOT entry holes. The adult beetles chew their way out to mate and lay eggs. Finding holes alone doesn’t tell you if the infestation is still active.
Frass (sawdust) — Fine, gritty dust below or around the holes. This is a mixture of chewed wood and beetle excrement. Fresh frass is cream-coloured or pale; old frass is grey or dark. Fresh frass beneath holes = active infestation.
Hollow sound — Tap the timber firmly. A dull, hollow sound suggests the interior has been extensively tunnelled.
Adult beetles — Small brown beetles (5–7mm for common furniture beetle) found dead on windowsills between May and September. This is the emergence season — if you find dead beetles near timber, there’s an active colony nearby.
Structural weakness — A screwdriver pushed into a badly affected beam will sink more easily than it should. Wood that crumbles or shows a layered, honeycomb interior when broken needs urgent professional assessment.
How Do You Tell If Woodworm Is Active or Old?
This is the most important question. Many older Spanish properties show signs of historic woodworm — infestations that self-resolved or were treated decades ago. Old, inactive holes are dusty inside, darkened, and produce no fresh frass.
The beeswax test: Fill a sample of holes with white beeswax or push tissue paper in firmly. Mark the date. Check in three months. If the tissue has been pushed out and there are new holes nearby, it’s active.
The spring check: Adult beetles emerge May–September. If you find tiny round holes that look fresh (clean, pale interior, no dust) in October, something bored its way out that summer.
Both cause timber damage, but they’re fundamentally different. Woodworm leaves round exit holes and fine dry sawdust. Termites leave no visible holes — they eat from inside, leaving a thin external shell. Termites also leave mud tubes along walls and produce hexagonal pellet droppings.
Treatment is completely different. If you’re unsure, get a professional diagnosis before spending money on the wrong product.
See our full guide: Termites in Spain — Identification, Risks & Treatment
How Do You Treat Woodworm Yourself in Spain?
For furniture, door frames, skirting boards, and non-structural timber with early to moderate infestations, DIY treatment is entirely feasible and cost-effective.
What Is the Best Woodworm Treatment Product in Spain?
Xylazel Carcoma Plus is the go-to product for treating woodworm in Spain. It’s a permethrin-based insecticide that penetrates into the wood, killing active larvae and preventing adult beetles from laying new eggs. It’s colourless, dries without leaving a sheen, and accepts varnish or paint once fully cured.
Available in three formats:
- Liquid (750ml brush-on) — for treating large surface areas like floor beams, furniture, and skirting boards
- Spray injection (400ml aerosol) — for injecting directly into exit holes to reach larvae deep within
- 2.5L bulk liquid — for large projects such as treating all roof timbers in a finca
Buy on Amazon.es — Xylazel Carcoma 2.5L or pick up the 750ml version at Leroy Merlin.
Corpol Matacarcoma is an alternative brush-on product — good for large surface areas where you want heavy, soaking application.
How Do You Apply Woodworm Treatment Step by Step?
What you’ll need:
- Xylazel Carcoma Plus (liquid + injection spray)
- Paintbrush (wide, for surfaces; thin, for crevices)
- Safety goggles and a respirator mask (treating holes can cause blowback)
- Disposable gloves
- Wood filler and sandpaper (for sealing holes after treatment)
Step 1: Prepare the surface. Remove old paint, varnish, or wax from affected timber where possible. The treatment penetrates raw wood far more effectively than finished surfaces.
Step 2: Apply the surface coat. Using a paintbrush, apply Xylazel Carcoma Plus generously to all affected timber. Don’t skim — you want the wood to be visibly wet. Work it into any cracks and along the grain.
Step 3: Inject the holes. Using the aerosol injection nozzle, press firmly into each exit hole and give a 1-second burst. The liquid should exit from nearby holes — this confirms it’s reaching the internal galleries. Wear your goggles. Blowback from adjacent holes is common and the spray is a skin and eye irritant.
Step 4: Treat surrounding timber. Even timber without visible holes should be treated preventively if it’s in the same area. Adult beetles lay eggs in cracks and rough surfaces — you want to break the next cycle.
Step 5: Apply a second coat. Wait 2–4 hours, then apply a second brush coat. On very dry, porous timber (common in old Spanish fincas), a third coat is warranted.
Step 6: Allow to cure fully. Wait 24–48 hours before applying wood filler, varnish, or paint. The treatment must soak in and dry completely. Painting over wet treatment traps it at the surface and reduces effectiveness.
Step 7: Fill the holes. Use wood filler to plug exit holes before refinishing. This is cosmetic but also helps you identify any new activity later.
Before buying, use this checklist to spot woodworm, termites, and other structural pests before you sign.
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When Is DIY Not Enough for Woodworm Treatment?
If the affected timber is load-bearing — roof beams, floor joists, structural supports — don’t attempt DIY treatment as your primary response. Here’s why:
Surface treatment and manual injection cannot penetrate the full cross-section of a large timber beam. A 200mm x 200mm oak beam that has been infested for a decade may have galleries throughout its interior that surface spray simply cannot reach.
Professional treatment options include:
Pressure injection — Specialists drill into the beam at calculated intervals and inject treatment fluid under pressure, ensuring full penetration. This is the gold standard for structural timber and comes with a 3-year guarantee from reputable companies.
Boron treatment — An increasingly popular alternative, boron-based products (borates) are low-toxicity, deeply penetrating, and effective against both beetles and fungi. Professional application ensures correct concentration and distribution.
Fumigation — For severe, widespread infestations (such as a whole roof structure), gas fumigation in a sealed space is the most effective solution. This is typically done by specialist companies such as Termite Doctor, Fumicosol, or Gimasur Ambiental.
When Should You Replace a Beam Instead of Treating It?
If a beam end shows extensive damage where a significant portion of its cross-section is affected, treatment cannot restore structural integrity. The beam needs to be replaced. This is an expensive job — typically 800–3,000 euros per beam when you factor in scaffolding, specialist carpenters, and matching historic timber — but a collapsing bóveda ceiling is far more expensive.
Get a structural engineer to assess any beam you’re unsure about before deciding between treatment and replacement.
How Much Does Professional Woodworm Treatment Cost in Spain?
| Job Type | Typical Cost Range |
|---|---|
| Furniture/fittings only (apartment) | €80–€150 |
| Small house, minor structural timber | €200–€400 |
| Rural finca/campo house (full roof treatment) | €500–€1,500 |
| Pressure injection of single beam | €80–€200 per beam |
| Full fumigation (large property) | €800–€2,500 |
Prices vary by region and company. Andalusia, the Costa Blanca, and Galicia tend to have more established specialist companies with competitive pricing. Get three quotes and ask specifically whether the quote covers a written guarantee.
In Spain, pest inspections are not standard in property purchase. Most estate agents will not mention them. But for any rural property, old townhouse, or property with exposed timber, a professional pest inspection — typically €150–€300 — is money extremely well spent.
A professional inspection report also becomes a negotiating tool: active woodworm infestation in structural beams justifies a meaningful reduction in the asking price or a seller’s obligation to remediate before completion.
More on this: Should You Get a Pest Inspection Before Buying Property in Spain?
How Do You Prevent Woodworm From Coming Back?
Treatment solves the current infestation. These steps prevent the next one:
Maintain wood finishes. Painted, varnished, or lacquered wood is significantly less attractive to egg-laying adult beetles than bare, rough-grained timber. Check finishes annually and touch up any cracks, chips, or bare patches — particularly on exterior timber, window frames, and roof eaves.
Control humidity. Wood-boring beetle larvae need a certain moisture content in timber to survive. Structurally, keep moisture below 20% if possible. Good ventilation under floors and in roof spaces is critical — especially in older Spanish rural properties where original ventilation may be inadequate.
Apply preventive treatment. When treating an active infestation, treat all nearby timber even if it shows no current signs. Xylazel Carcoma Plus provides residual protection that deters adult beetles from laying eggs in treated surfaces for several years.
Inspect annually. Get into the habit of checking beams and timber each spring (April–May, just before the adult flight season) for fresh holes or sawdust deposits.
Source new timber carefully. If renovating, ensure all new timber has been kiln-dried and is pre-treated. Bringing in untreated timber is one of the most common ways infestations are introduced into otherwise clean properties.
Quick Reference: What to Do
- Identify the pest — round holes + fine sawdust = woodworm (carcoma). Mud tubes + no holes = termites. Get a professional opinion if uncertain.
- Check if it’s active — fresh frass, clean holes, beetles found in summer = treat immediately.
- Assess the timber type — furniture and non-structural = DIY treatment fine. Structural beams = professional assessment first.
- Buy Xylazel Carcoma Plus from Amazon.es or Leroy Merlin, and follow the injection + surface coat method above.
- Get professional quotes for structural work — three quotes, ask for a written guarantee.
- Maintain prevention — annual checks, maintained timber finishes, controlled humidity.
Woodworm in a Spanish property is not a crisis — it’s a very common problem with well-established solutions. The key is acting on it, not ignoring it. Small-bore holes in a chair are manageable; honeycombed roof beams in a finca are a structural hazard.
If you’re buying rather than treating, read our pre-purchase pest inspection guide before you sign anything.
Written by James Thornton
Founder & Lead Writer
British expat living in Málaga since 2019. Researched 200+ pest control cases across 16 Spanish regions.
Reviewed by Carlos Ruiz Martín
ROESBA-certified (Spain's Official Pest Control Registry). DDD specialist. Member of ANECPLA.
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