At your wits' end wondering how to get rid of woodworm?
Woodworm – not actually worms at all, by the way – are the wood-eating larvae of lots of different species of beetle - usually the Common Furniture Beetle (niche name).
These larvae bore small round holes in furniture, beams and flooring as they exit the timber, leaving behind a powdery residue. The woodworm will happily spread from one piece of wood to another, ultimately causing damage – and in some cases, serious structural problems.
Look out for bore dust, or frass, caused by emerging beetles. They instinctively head towards the light, so you might spot them around loft hatches or near windows.
Not sure if this the pest you're dealing with? Check out our how to identify bugs to find out which unwanted guest has invaded your home.
Experts at The British Pest Control Association explain more: 'Woodworm is frequently introduced into the house in second-hand furniture, tea chests or wicker-work; but the beetles are quite capable of flying in through a window from nearby dead branches of trees.'
'They may then attack floorboards, joinery and, more seriously, structural timbers such as rafters and joists.'
For this reason, it's vital to get rid of woodworm as soon as you spot the signs. Use our guide to find out how.
- Find out about how to repair wooden floors including those riddled with woodworm.
What are the signs of woodworm?
The first step to figuring out how to get rid of woodworm is looking out for the common signs.
The British Pest Control Association describe the very first sign to look out for:
'The first sign of woodworm is the appearance of neat round holes, 2mm across, in wooden surfaces, often accompanied by tiny piles of wood dust beneath them. Fresh holes show clean white wood inside. Emerging adult beetles make the holes. Immature grubs may still be tunnelling away inside the wood.'
New exit holes: look out for these in furniture, beams and flooring; they're particularly likely to appear from May to October when woodworm are active. Don't believe anyone who tells you that the holes are a sign that the woodworm have left. In fact, it's entirely possible that new larvae will be within the wood.
Dust around the holes: this might be the first thing you notice. It's not actually dust; nope, this powdery residue we mentioned earlier is droppings, and just looks like fine sawdust.
Weak floorboards or beams: this is a sign of a serious woodworm infestation.
Larvae: they're creamy white in colour and look like little grubs, but are smaller than the tip of a pencil so difficult to spot.
Beetles: dead or alive; they are around 3mm long and brownish/black.
Where does woodworm come from
Woodworm may have come into a house on a piece of old furniture or infested timber. Bear this in mind when antique shopping – if there are fresh signs of woodworm in a piece, give it a wide berth.
The adult beetles lay eggs on, or just under the surface of, a piece of wood; the larvae then feed on it before pupating and hatching. The cycle is then repeated.
The larvae like their timber habitat to have a higher moisture content than is typical, so it's likely, if you discover a woodworm problem in your home, that there is also a problem with excess damp, whether in a poorly ventilated roof or damp cellar. However, damp conditions are not a must.
- See our guide to How to choose the best reclaimed wood flooring to make sure you avoid woodworm in the first place.
Preventing woodworm infestations
As with any infestation, preventing woodworm is better than treating it. Removing humidity by ensuring rooms are properly heated and ventilated will make your home less attractive to woodworm as they need a certain about humidity to breed.
If you are worried about the damp in structural timbers and floorboards, you can test its humidity with a timber moisture meter. Any moisture content reading over 20 per cent will need dealing with.
If you can pinpoint the woodworm to any newly-bought, single piece of furniture or have spotted an early, isolated infestation, getting rid of the affected piece(s) could prevent or at least minimise any further woodworm invasions in the rest of the house.
Treat woodworm yourself or call in professionals?
If you suspect a woodworm infestation, it's always worth asking a trusted professional before attempting a DIY treatment.
Why? Well, while all woodworm signs might look the same to the untrained eye, different types of beetle like to munch on different types of wood. Some, for example, will target loft beams, others like hardwoods; this means some will cause structural damage, while others might just ruin your favourite family heirloom...
However, there are lots of DIY products are readily available to treat infested furniture, including woodworm killer solutions that are suitable for use on tables and chairs.
In the case of a severe infestation or particularly delicate antique furniture, advanced technologies can help, such as Controlled Atmosphere Technology (CAT), which involves using inert gases in a controlled atmosphere to eliminate all life stages of the insects, including eggs and larvae, while leaving no harmful residues.
When repairing antique furniture that has suffered woodworm damage, it is best is to seek advice from restoration specialists.
- Find out more about how to clean and polish wood furniture in our in-depth guide.
How to get rid of woodworm on a DIY basis
If you are confident that the woodworm infestation is small and limited, perhaps to a piece of furniture, you can try treating it with a good quality, low odour boron-based liquid pesticide, following the instructions to the letter and keeping the treatment well away from pets and your kids.
Another option is to put out fly traps in poorly-ventilated rooms; these may catch some of the emerging beetles, but it's a long shot.
It's worth knowing that there's no guarantee that DIY methods will work because these types of treatment do not penetrate much past the surface of the wood.
They might kill adult beetles as they emerge, but won't reach any larvae inside. And if they don't emerge immediately, they won't be affected by the insecticide you've used – and only repeated treatments will ensure they are.
And... the longer your method takes to work, the longer the woodworm have to breed and multiply.
Rentokil also stipulate that it depends where you are seeing the signs: '... if you have spotted signs of woodworm in structural timber such as rafters, beams or large areas such as floorboards, skirting or stairs then DIY products are not recommended.'
Using professionals to get rid of woodworm
If your woodworm infestation is widespread, prolonged or in the structural parts of your property, a thorough chemical treatment by a professional is your best option.
It's important to ensure the company you appoint to do the work is qualified. Check they have the correct certifications in place, that they are members of an industry association, such as Property Care Association, and that they are insured for the work they will be doing.
Recommendations from friends and family are important, but if you can't get any, you could check online reviews to see how other customers have found them. No online reviews? Ask the company if they can put you in touch with former customers so that you can find out more.
Finally, as with any work, get more than one quote in writing, and ensure the quote is a quote and not an estimate. Get in writing what will be involved and how long the work will take, too.
The company's response to all these requests will help demonstrate their professionalism, too.
What to do if woodworm has infested structural beams and floors
If the timbers in your home have been structurally compromised – you'll know this if the wood crumbles or breaks when you touch it – it's worth getting professional advice about whether it will be more cost effective to cut away and replace the damaged parts, or better to remove and replace them in their entirety.
Bear in mind that a woodworm infestation doesn't necessarily mean that timbers will be structurally affected, since woodworm usually only infect the upper layer of wood. Caught early, you may find that the repairs are not as drastic as you might first have feared.
Find out more about maintaining old timber frame buildings.