Woodworm in exterior woodwork
Woodworm is often confused with wood rot, but the cause and approach are different: wood rot is fungal decay caused by moisture, while woodworm is damage caused by the larval stage of wood-boring beetles. Both often start unnoticed under the paint layer.

Cause
Woodworm occurs when wood-boring beetles lay eggs in cracks, crevices or untreated wood. The larvae then eat their way through the wood, which becomes visible on the surface over time.
How to recognise it
- Small, round exit holes a few millimeters wide in the wood
- Fine, powdery sawdust (bore dust) under or around the holes
- Wood that feels locally weakened where affected
What's the risk?
- Active infestation can spread to other woodwork nearby
- The structural strength of the wood can decrease with prolonged infestation
- Paint often conceals the first signs, so it is only noticed late
The solution
We first assess whether the infestation is still active. For limited, localized damage, we repair the wood and treat it specifically before repainting. For extensive or active infestation, we advise replacing the affected part.
Where there is doubt about the extent, we refer to a specialized woodworm control expert before continuing with paintwork.
When painting is enough
If the infestation is old and no longer active and the wood is still sufficiently strong, it can simply be repainted after repair.
When repair is needed
For active infestation or clearly weakened wood, treatment or replacement of the affected part is needed first.
How Painting Company solves it
- Assessing whether the infestation is active or old
- Repairing limited, localized damage
- Referring on for extensive or active infestation
- Repainting with a protective system after repair
Preventing woodworm in exterior woodwork: practical maintenance
The best way to prevent woodworm in exterior woodwork is to regularly check the spots where the problem most often starts, and fix small defects straight away instead of waiting. Woodworm occurs when wood-boring beetles lay eggs in cracks, crevices or untreated wood. The larvae then eat their way through the wood, which becomes visible on the surface over time.
A fixed maintenance cycle — for example periodically touching up vulnerable spots such as sealant joints, corners and sills — is often cheaper than waiting until a problem shows up in full. Not sure whether your situation needs attention? A free, no-obligation inspection gives you clarity.
Why choose Painting Company
Painting Company has now completed over 1374 projects and serves more than 261 VvE's, with a team of 14+ permanent painters and an average Google rating of 4.9. With woodworm in exterior woodwork, it's not just about the visible paint layer but also the structural repair underneath — we have daily experience with exactly that.
As part of CrumBouw and GoedkoopSteigerHuren.nl, we can combine this with wood rot repair and, if the situation calls for it, scaffolding — all through a single point of contact. Request a free, no-obligation quote, and we'll think it through with you.
Frequently asked questions about woodworm in exterior woodwork
Is woodworm the same as wood rot?
No. Wood rot is fungal decay caused by moisture, woodworm is damage caused by the larvae of wood-boring beetles. The approach differs accordingly.
Can you treat woodworm yourselves?
We repair and paint affected wood after treatment. For active, extensive infestation, we refer to a specialized woodworm control expert.
Can I fix woodworm in exterior woodwork myself, or is this a job for a professional?
Small, surface-level cases can sometimes be touched up yourself, but if you're unsure we'd advise against it. We first assess whether the infestation is still active. For limited, localized damage, we repair the wood and treat it specifically before repainting. For extensive or active infestation, we advise replacing the affected part. Repairs done incorrectly often end up costing more in the long run than calling a professional painter straight away.
How long does it take to fix woodworm in exterior woodwork?
That depends a lot on the extent and accessibility of the spot. For a limited, localised case the work is often done within a day or a few days; larger areas take longer. During the free assessment we give a concrete estimate for your situation.
What does it cost to fix woodworm in exterior woodwork?
That varies by situation — the extent, the accessibility and whether painting is also needed all play a role. We give a clear quote after a free, no-obligation assessment, so you know exactly where you stand beforehand.
What happens if I ignore woodworm in exterior woodwork?
Active infestation can spread to other woodwork nearby The longer you wait, the bigger the eventual repair — and the cost that comes with it — tends to be.
What's the best time of year to have this addressed?
We prefer to carry out exterior work in dry weather at a moderate temperature, usually from spring to autumn. Repairing acute damage — such as cutting out rotten wood — can however often be done year-round, so the problem doesn't get worse while you wait for better weather.
How do I stop woodworm in exterior woodwork coming back after it's fixed?
We address not just the visible symptom but also the underlying cause — woodworm occurs when wood-boring beetles lay eggs in cracks, crevices or untreated wood. The larvae then eat their way through the wood, which becomes visible on the surface over time. Periodic maintenance also helps: touching up small damage in time prevents a small problem growing back into a bigger repair.
What materials and techniques do you use for this?
We work with professional materials and paint systems matched to the surface and the load it faces — not standard DIY-store paint. Where needed we combine that with specialised wood repair systems or primers matched to the specific cause.
Do you offer a guarantee on the repair work?
We always discuss guarantee terms upfront and set them out clearly in the quote, so you know exactly what to expect before we start.
Can you combine this with wood rot repair?
Yes, we combine this regularly. If we're already on site for wood rot repair, it's often more efficient to include this in the same schedule rather than planning it separately.
Is woodworm in exterior woodwork worse on older or listed buildings?
This comes up more often on older properties, simply because the woodwork and facades have been exposed to the weather for longer and often already carry several layers of paint. On listed-building details we work with extra care to preserve the original profiling and appearance.
How do I spot early signs, before it's visibly bad?
Small, round exit holes a few millimeters wide in the wood
Is a visual inspection enough, or is more investigation needed?
In most cases a thorough visual inspection by a professional painter is enough to determine the extent. If there's doubt about the underlying structure, we look a little deeper, for example by gently testing whether the wood can still bear weight.
Do you also work on commercial buildings and real estate, not just homes?
Yes. We fix woodworm in exterior woodwork for private homes, VvE's and real estate such as commercial buildings and apartment blocks. The approach is similar, though larger properties are often planned in phases.
Can woodworm in exterior woodwork affect the value of my home?
Visible damage to window frames, facades or woodwork can create a negative impression during a sale or valuation and raise questions about deferred maintenance. Addressing it in time avoids that discussion and keeps the property looking well cared for.
Do I need to prepare anything before you come round?
No, that's not necessary. Just make sure the spot is reasonably accessible; we handle everything else, from inspection to execution.
Do you use scaffolding if the spot is high up or hard to reach?
If the situation calls for it, we arrange that through GoedkoopSteigerHuren.nl, part of the same organisation as Painting Company. We combine that into a single request, which saves coordination steps.
How quickly can you come round for an assessment?
We respond to requests quickly and schedule the assessment as soon as possible in consultation with you. Request a free, no-obligation quote and we'll get in touch.
What's the difference between touching up and a full repair?
If the infestation is old and no longer active and the wood is still sufficiently strong, it can simply be repainted after repair. For active infestation or clearly weakened wood, treatment or replacement of the affected part is needed first.
Ready for your next project?
Request a free, no-obligation quote today. We get in touch, think along with you and deliver the best paintwork for your home, VvE or property.