The best woodworm killers, compared.
Top pick: Ronseal woodworm killer 1 litre Best value: Rentokil PWT25 woodworm treatment fluid 250 ml – About £9.59 with 4.5 from 629 reviews, for one movable piece if you can work around the nozzle. Updated October 2026.
A woodworm killer is a ready-to-use preservative meant to kill wood-boring beetle larvae, eggs or adults in timber, and often to leave a residue against a fresh attack. It is not a garden insecticide, a stain or a rot treatment. On amazon.co.uk this set is liquids and trigger sprays, mostly water-based, with permethrin named only where a listing states an active. You judge a tin by whether the holes are active, whether the timber is a chair or a joist, whether the label allows amateur use, and whether the wood needs drying more than spraying. The Association says a dead attack does not justify treatment. The scores are the card scores from that extract. The [woodworm killer buying guide](/hub/raised-beds-greenhouses-and-compost/woodworm-killer/sub/woodworm-killer-buying-guide) sets those checks before the brand. Lignum is non-solvent and worded for interior use. Soluguard is solvent-free, with 0.2% permethrin, for brush or spray.
A woodworm killer is a ready-to-use preservative meant to kill wood-boring beetle larvae, eggs or adults in timber, and often to leave a residue against a fresh attack.
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Personal buying guide
Question 1 of 2
What are you treating?
This 1 litre tin is titled Ronseal woodworm killer, while the brand field says Thompson's and the manufacturer is Sherwin-Williams. Recommended uses say exterior wood, the base line lists oil, solvent, and water, and coverage is stated as up to 10 m² per litre. In the 16 October 2026 extract it is £17.85 and 4.8 out of 5 from 7 reviews. This extract has no review texts, and the listing asks whether it is safe for indoor use and does not answer. An active ingredient is not stated. A 4.8 from seven ratings, with no written reviews, is too thin to treat as a result on a chair or a joist.
Pros
Cons
Best for: Exterior wood, if the tin you receive matches the Ronseal title and you accept coverage stated as up to 10 m² per litre.
Less suitable: Indoor furniture, or anyone who needs written reviews rather than a 4.8 from seven ratings.
Specifications
Common questions
Is this listed for indoor use?
The recommended-uses field says exterior wood. The listing asks whether it is safe for indoor use and does not answer.
Who is the brand?
The title says Ronseal. The brand field says Thompson's. The manufacturer is Sherwin-Williams.
What do the reviews say?
The listing shows 4.8 out of 5 from 7 reviews. This extract has no review texts.
This Rentokil bottle is 500 ml at £12.87 in the 16 October 2026 extract, rated 4.7 out of 5 from 25 reviews. The included-components line says woodworm killer solution, and four short UK reviews are all positive. The bullets say easy to use and value for money, and they do not say whether it kills larvae. One bullet says the box contains a Sterntaler toy sheep, which matches neither the title nor the reviews. The listing does not name a base, an active ingredient, a coverage rate, or whether it is for indoor use. It also asks about pets and does not answer.
Pros
Cons
Best for: A small top-up if you already know this Rentokil tin and you ignore the toy-sheep bullet.
Less suitable: A first buy where you need a stated active ingredient, a coverage rate, or a longer UK review record.
Specifications
Common questions
Does it kill larvae?
The listing asks and does not answer. The bullets say easy to use and value for money.
What is the toy-sheep line?
One bullet says the box contains a Sterntaler toy sheep. The title, the included-components line, and the reviews are the 500 ml woodworm fluid.
Is it safe for pets?
The listing asks and does not answer.
This 5 litre Ronseal fluid is listed as a spray, and the bullets say it kills wood-boring beetles, their larvae and eggs, and that it penetrates deeply. In the 16 October 2026 extract it is £40.76 and 4.6 out of 5 from 23 reviews, the highest 5 litre price in this set. The four review texts hope it works, note foaming when brushed on, or say it is too soon to judge. None of those texts describe a finished result. The listing asks whether it is safe for indoor use and does not answer. It also leaves the base and the active ingredient unstated.
Pros
Cons
Best for: A measured area where you specifically want eggs named on a Ronseal 5 litre listing.
Less suitable: Anyone who wants a reported result before spending £40.76, or an indoor job the listing does not confirm.
Specifications
Common questions
Is it safe for indoor use?
The listing asks and does not answer.
Does it name eggs?
Yes. The bullets say it is formulated to kill wood-boring beetles, their larvae and eggs.
What do the four review texts say?
They hope it works, note foaming when brushed on, or say it is too soon to judge. None describe a finished result.
This 250 ml Rentokil fluid is £9.59 in the 16 October 2026 extract and 4.5 out of 5 from 629 reviews, and a bullet says it can now be used indoors and outdoors. UK reviews cover tables and sideboards, including a mango sideboard, and some report no stain and no varnish damage. Other reports say varnished wood needed extra coats because the fluid would not soak in. Reviewers say the nozzle is too wide for flight holes, that fluid spills, and that the bottle is hard to squeeze onto a floor or a vertical face, so some used a pipette. Dust was still there after repeated coats in reviews, so you should not judge it on the same evening. The listing asks whether it is rainproof and does not answer, and it does not name an active ingredient. It is our best value for one movable piece when you can work around that nozzle.
Pros
Cons
Best for: One chair, table, or sideboard, where the indoors-and-outdoors bullet matches the piece.
Less suitable: A bare floor, a varnished surface you will not strip, or flight holes the wide nozzle cannot reach.
Specifications
Common questions
Can it be used outdoors?
A bullet says it can now be used indoors and outdoors. The listing asks whether it is rainproof and does not answer.
Will it mark a varnish?
The listing does not say. UK reviews include reports of no stain and no varnish damage, and other reports that varnished wood needed extra coats because the fluid would not soak in.
What is wrong with the nozzle?
Reviewers say the nozzle is too wide for flight holes, that fluid spills, and that the bottle is hard to squeeze onto a floor or a vertical face. Some used a pipette.
This Timpest fluid is a clear, solvent-based, ready-to-use liquid from Italy, at £31.00 in the 16 October 2026 extract. The unit count says 2,500 ml and the item weight says 1.01 kg, so the pack size on the page disagrees with itself. A bullet says it will not damage paint, gilding, cloth, or paper, which is the maker's claim rather than a result in these reviews. The star line is 4.5 out of 5 from 497 reviews, and the texts in this extract are headed as reviewed in Italy, mentioning furniture and parquet. Larvae are named and eggs are not. The listing asks about indoor use and about antique furniture and does not answer.
Pros
Cons
Best for: A buyer who can confirm the fill volume on the tin and does not treat the Italian reviews as a UK result.
Less suitable: UK furniture where you need UK review texts, or a water-based indoor job.
Specifications
Common questions
Can it be used on antique furniture?
The listing asks and does not answer. A bullet says it will not damage paint, gilding, cloth, or paper upholstery.
Is it safe for indoor use?
The listing asks and does not answer. Review texts mention furniture and parquet. Those reviews are from Italy.
Are the reviews from the UK?
No. The star line is 4.5 from 497 reviews, and the texts in this extract are headed as reviewed in Italy.
This 1 litre Lignum fluid is listed for interior use, clear, non-solvent, and VOC-free. The bullets say it kills an active infestation of wood-boring insects and prevents attack, and that it is BS EN tested, without naming an active ingredient or a coverage rate. In the 16 October 2026 extract it is £10.97 and 4.5 out of 5 from 204 amazon.co.uk reviews. One UK reviewer brushed it on, left it a couple of days, then painted over it. The item form says spray, and the country of origin is the United Kingdom. The listing still asks whether it is safe for indoor use and does not answer, so that prompt sits next to an interior-use bullet.
Pros
Cons
Best for: Bare interior timber you can brush, then paint once it has had a couple of days.
Less suitable: Outdoor timber, a raised bed in soil contact, or a job that needs a named active ingredient and a printed coverage rate.
Specifications
Common questions
Is this for indoor use?
A bullet says interior use. The listing also asks whether it is safe for indoor use and does not answer that question.
Can it be painted over?
The listing does not say. One UK reviewer brushed it on, left it a couple of days, then painted over it.
Does the listing name an active ingredient?
No. It says the fluid kills an active infestation of wood-boring insects and prevents attack, and that it is BS EN tested. No active is named.
This 5 litre Lignum pack repeats the 1 litre claims: interior use, quick drying, non-solvent, VOC-free, and BS EN tested. It weighs 5.35 kg and, in the 16 October 2026 extract, costs £24.39, the lowest 5 litre price in this set. The star line is 4.5 out of 5 from 204 reviews. The review texts in this extract use the same names, dates, and wording as the 1 litre Lignum file, so this size does not bring its own buyer record. No active ingredient or coverage rate is printed. The interior-use bullet makes it the wrong fluid for a raised bed or other timber in soil contact.
Pros
Cons
Best for: A measured interior area when you want the Lignum claims in a 5 litre tin.
Less suitable: A raised bed, greenhouse timber in soil contact, or a buyer who needs reviews written about this size.
Specifications
Common questions
Is this the same claims as the 1 litre Lignum tin?
The bullets match: interior use, quick drying, non-solvent, VOC-free, and BS EN tested. This pack is 5 litres and weighs 5.35 kg.
Are the review texts unique to this size?
The star line is 4.5 from 204 reviews. The review texts in this extract use the same names, dates, and wording as the 1 litre Lignum file.
Is it for outdoor timber?
The bullet says interior use. The listing asks about all wood types and indoor safety and does not answer those questions.
This 1 litre Zero In trigger spray is a ready-to-use water-based permethrin fluid for internal wooden furniture and living areas. The bullets name woodworm, longhorn, furniture beetles, and termites, and they claim prevention of re-infestation for 5 years. In the 16 October 2026 extract it is £7.99, the lowest price in this set, and 4.5 out of 5 from 5 reviews. Two UK review texts are positive. The listing does not state the permethrin strength or a coverage rate, and an item weight of 100 g conflicts with a 1 litre fill. Outdoor furniture is asked and not answered. A termite line on the bullets is not a reason to buy it for a UK house.
Pros
Cons
Best for: Internal furniture in a lived-in room when you want a cheap trigger spray and can accept five reviews.
Less suitable: A roof, outdoor furniture, or anyone who needs a stated permethrin percentage and a larger review record.
Specifications
Common questions
Can it be used on outdoor furniture?
The listing asks and does not answer. The bullets say internal wooden furniture and living areas.
What insects does the listing name?
Woodworm, longhorn, furniture beetles, and termites. It also claims prevention of re-infestation for 5 years.
How many review texts are there?
Two, both from the United Kingdom, and both positive. The star line is 4.5 from 5 reviews.
The Soluguard pack is two 500 ml solvent-free bottles, 1,000 ml in total, with 0.2% permethrin that the listing says you can brush or spray. It prints coverage of 1.65 m² and names eggs, larvae, and adult beetles. In the 16 October 2026 extract it is £15.98 and 4.4 out of 5 from 6,621 amazon.co.uk reviews. UK reviews describe overpainting once the fluid is dry, and one reviewer found mahogany a poor result. Floors can keep producing fresh dust after treatment, so a quiet week is not proof the attack has stopped. One reviewer shut the cats out and described the fluid as toxic to them. It is our top pick when you want a named permethrin strength and a long UK review record, and you keep pets away until the tin says it is dry.
Pros
Cons
Best for: A chair or a small bare area where you want 0.2% permethrin printed on the listing and a long UK review record.
Less suitable: A measured floor that needs more than the stated 1.65 m², hardwood such as mahogany, or a room where pets cannot be kept out until the tin says it is dry.
Specifications
Common questions
What pack size is this?
The title says a pack of two 500 ml bottles. The unit count and liquid volume are both 1,000 ml. The listing says the details apply to each unit, and it states coverage of 1.65 m².
Can it be painted over?
The listing asks this and does not answer it. UK reviews describe overpainting once the fluid is dry.
Is it safe around pets?
The listing asks and does not answer. One UK reviewer shut the cats out and described the fluid as toxic to them.
This 1 litre Cuprinol bottle is water-based, with low-odour wording, at £15.99 and 4.4 out of 5 from 105 reviews in the 16 October 2026 extract. Recommended uses say interior wood surfaces, while the item type says exterior woodcare. Coverage is printed as up to 53.82 square feet per litre, and the bullets name larvae rather than eggs. One UK reviewer sprayed rafters and still mentioned the smell. Another said the container states 3 days to dry, which the listing itself does not print. You would check the tin for eggs and for whether this bottle is the interior fluid or the exterior item type.
Pros
Cons
Best for: Interior wood you can leave for the 3 days one reviewer read on the container, if the tin agrees with the interior wording.
Less suitable: A job that needs eggs named on the listing, or a rafter space where a low-odour claim still left a smell in a review.
Specifications
Common questions
Is it for indoors or outdoors?
Recommended uses say interior wood surfaces. The item type is exterior woodcare. One UK reviewer sprayed rafters.
Does it kill eggs?
The listing asks. The bullet says it kills all types of wood-boring beetle larvae. Eggs are not named.
How long does it take to dry?
The listing does not give a drying time. One reviewer said the container states 3 days to dry.
This Barrettine bottle is 500 ml and ready to use in the title, with oil as the item form. In the 16 October 2026 extract it is £10.66 and 4.3 out of 5 from 98 reviews. One UK review calls it a convenient spray bottle, and another says the smell is not overwhelming. Several reviewers say it works or killed woodworm, while others say it is too soon to judge, and the texts are short. The listing asks about wood types, an applicator, and indoor use, and does not answer. No active ingredient or coverage is printed on this amazon.co.uk extract, so the rate is whatever the tin in your hand states.
Pros
Cons
Best for: A small piece when you want a ready-to-use 500 ml bottle and you will read the tin for the rate.
Less suitable: A large bare area, or anyone who needs the listing itself to name the active ingredient and confirm indoor use.
Specifications
Common questions
Does it come with an applicator?
The listing asks and does not answer. One UK review calls it a convenient spray bottle.
Is it safe for indoor use?
The listing asks and does not answer. One review says the smell is not overwhelming.
Do reviewers know if it worked?
Several say it works or killed woodworm. Others say it is too soon to judge. The texts are short.
This 5 litre Cuprinol tin is a water-based fluid at £28.95 in the 16 October 2026 extract, rated 4.1 out of 5 from 40 reviews. The bullets say low odour, long lasting, and that it prevents re-infestation. They do not state indoor or exterior use, and they do not name an active ingredient or a coverage rate. Some UK reviews say the tin was well packed. Others report a dented or rusty tin, a taped cap, or a tin that looked as if it could split. The listing asks about indoor use and about pets and does not answer either question.
Pros
Cons
Best for: A measured area once the tin itself states the use and the rate, and you can check the container on arrival.
Less suitable: A single chair, a delivery you cannot inspect, or a loft where bats have not been ruled out.
Specifications
Common questions
Can it be used indoors?
The listing asks and does not answer. The bullets say it is water-based and low odour. They do not state indoor or exterior use.
Is it safe for pets?
The listing asks and does not answer.
How did the tins arrive?
Some UK reviews say the tin was well packed. Others report a dented, rusty tin, a taped cap, or a tin that looked as if it could split.
Twelve woodworm killers are on this page. The card scores come from the amazon.co.uk extract of 16 October 2026. There is no laboratory test. A named active, a stated use, a printed coverage figure and a UK review record raise a card. A thin review file, a brand clash, a weight that disagrees with the fill, and review texts from outside the UK pull a card down. A termite line is not scored as a UK reason to buy.
Fresh attack and the timber
25%Fresh dust in small holes is the reason to treat. Dark old holes are not. A chair you can move is a different job from a joist, a stair or a roof.
Amateur use wording
20%The tin has to be an amateur product, then interior or exterior. A clash between recommended uses and the item type is a deduction.
Named active and base
20%Permethrin named on the listing, and a water-based, solvent-free or solvent base, score above a card that leaves the active blank.
Pack against a stated rate
15%Litres only help after a coverage figure or a label rate. A 5 litre tin with no rate is not scored as a larger result.
Reviews and price for the job
20%amazon.co.uk stars and review counts, whether the texts are from the UK, and the shelf price for that size of job.
Name the attack and the timber before you compare stars. A chair with fresh dust, a measured run of bare boards, and a raised bed in soil contact are different jobs. Prices on this page are amazon.co.uk captures from 16 October 2026, from about £7.99 to about £40.76.
A woodworm killer is a ready-to-use preservative meant to kill wood-boring beetle larvae, eggs or adults in timber, and often to leave a residue against a fresh attack. It is not a garden insecticide, a stain or a rot treatment. Water-based fluids dominate this amazon.co.uk set. Cuprinol is described as low odour. Lignum is non-solvent and worded for interior use. Zero In is a water-based permethrin trigger spray. Soluguard is solvent-free, with 0.2% permethrin, for brush or spray.
The Property Care Association says a dead attack does not justify treatment. Dark holes without fresh dust are usually old. Dry sound timber comes before a tin.
Rentokil reviews say varnished wood may need extra coats because the fluid will not soak in. Lignum reviewers who painted waited a couple of days. Do not judge the job on the same evening.
Lignum's bullets say interior use. An interior woodworm killer is the wrong product for timber in soil contact. Treat rot and ground contact first.
Holes about 1–2 mm with fine fresh frass suggest active common furniture beetle, which is the British Pest Control Association description. Dark holes without fresh dust are usually old. The Society for the Protection of Ancient Buildings says historic attack is common in sound timber, and that you dry the timber first. The Property Care Association says a dead attack does not justify treatment. No fresh dust means you monitor, not that you buy a tin.
The Health and Safety Executive limits the public to amateur products. Check the number on the tin against the current list, and use the fluid in its original container at the label rate. Then read interior or exterior wording, and whether the base is water-based or solvent. Lignum's bullets say interior use. Ronseal 1 litre's recommended-uses field says exterior wood.
Three typical situations, each with a recommendation from this comparison.
You can see fine fresh dust in a chair, a table or a sideboard, and the label allows amateur use. Rentokil PWT25 is 250 ml at about £9.59, with an indoors-and-outdoors bullet. The nozzle is wide, and some buyers used a pipette.
You want 0.2% permethrin printed, and a long UK review record, on a chair or a small bare area. Soluguard is two 500 ml bottles at about £15.98. The stated coverage is 1.65 m², so it is not a floor.
You have already measured the bare boards and you want an interior 5 litre tin. Lignum 5 litres is about £24.39, the lowest 5 litre price here, and the bullets say interior use. The listing prints no rate, so the tin you open governs.
Twelve listings do not share one job. Soluguard, two 500 ml bottles at about £15.98, is the top pick when you want 0.2% permethrin and 4.4 from 6,621 amazon.co.uk reviews, and the area is within the stated 1.65 m². Rentokil PWT25, 250 ml at about £9.59, is the best value for one chair or sideboard: 4.5 from 629 reviews, with a wide nozzle you may have to work around. A 5 litre tin is a separate buy, and only after you have measured against the rate on that tin. Old dark holes, a joist you cannot see, and a raised bed in soil contact are reasons to stop.
Rentokil PWT25 woodworm treatment fluid 250 ml
About £9.59 with 4.5 from 629 reviews, for one movable piece if you can work around the nozzle.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK and manufacturer sources from the research digest, last checked on 16 October 2026.
This article contains affiliate links. If you buy through these links, we may earn a commission at no extra cost to you. The cards use amazon.co.uk listing data and public UK sources. They are not a laboratory test.
