Woodworm Treatment Cost: 2026 UK Price Guide

One of the first questions homeowners ask once they find woodworm is, understandably, what it will cost to put right. The honest answer is that it depends, mainly on how much timber is affected, how easy that timber is to reach, and whether any of it needs repairing as well as treating. The good news is that most woodworm jobs fall within fairly predictable ranges, and a free survey turns those ranges into a fixed written price for your specific property.

This guide breaks down realistic 2026 UK costs by the part of the house involved, explains what pushes a price up or down, and weighs the savings of DIY against a guaranteed professional treatment.

Typical 2026 woodworm treatment costs

The figures below are indicative market ranges for treating an active infestation. Reputable firms quote a fixed price after a survey, so treat these as a guide rather than a fixed tariff. Prices usually exclude VAT and any building repairs.

Area treated	Typical cost (ex VAT)
Single garage or small room	from £200
Roof space / loft	from £400
Suspended timber floor (per floor)	£200–£600
Whole house	£500–£3,000

These cover the insecticidal treatment itself. Lifting and relaying floorboards, structural timber repairs, and resolving damp or rot are usually costed separately. For a fuller breakdown and live examples, see our main woodworm treatment cost page.

Single room or garage

A contained infestation in one room, an integral garage or an outbuilding is the most affordable scenario, typically from around £200 plus VAT. The timber is accessible, the area is small, and a couple of coats of water-based permethrin to the affected surfaces is usually all that is required. Most jobs of this size are completed in a few hours.

Roof space

Loft and roof treatment starts from around £400 plus VAT. Roofs hold a lot of timber, including rafters, purlins, joists and the wall plates where damp often collects, so there is more surface to cover. Access is awkward, and there is an important legal point: bats are protected by law, and disturbing a roost is an offence. Where bats may be present, a check is needed before any treatment, which a professional will factor into the plan. You can read more about roof-specific work on the woodworm treatment hub.

Floors and joists

Treating a suspended timber floor commonly costs between £200 and £600 plus VAT per floor. Cost depends heavily on access: where boards lift easily the work is quick, but if joists must be reached from below or boards have to be taken up and relaid, labour rises. Floors are also a common place to find damp-related infestation, so the survey will check whether the underlying cause needs addressing too.

Whole house

A property-wide infestation typically falls between £500 and £3,000 plus VAT. The wide range reflects how much the scope can vary, from a few connected areas in a small terrace to extensive treatment of every floor and the roof in a large period home. Severe or widespread cases may call for fogging or boron paste on structural members rather than spray alone, which affects the figure.

What a free survey includes (and why it pays for itself)

Most reputable firms survey for free because an accurate diagnosis is in everyone’s interest. A proper survey is where a vague worry becomes a fixed, defensible price, and it typically covers:

• Confirming the infestation is active, rather than old, dead damage that needs no treatment at all.
• Identifying the species, since a common furniture beetle job and a death watch beetle job in structural oak are priced very differently.
• Measuring timber moisture, because damp is the usual driver of infestation and may need resolving for the treatment to last.
• Mapping the affected timber and assessing whether any of it is weakened enough to need repair.
• A written report and a fixed quote, so you know exactly what is included before any work begins.

That last point is what protects you financially. A fixed written quote, ideally from a firm whose surveyors work to recognised standards such as those promoted by the Property Care Association, removes the open-ended “and another £x for that” surprises that turn a small job into an expensive one. The free survey also stops the single most common waste of money in this field: paying to treat timber where the woodworm died out years ago.

What drives the price up or down

Two identical-looking infestations can be quoted very differently. The main factors a surveyor weighs are:

• Extent of the infestation. More affected timber means more material, labour and time. A localised problem is far cheaper than a property-wide one.
• Access. Easy-to-reach surfaces are quick to treat. Lifting fitted floors, working in cramped sub-floor voids, or reaching high roof timbers all add labour.
• Species and severity. Common furniture beetle in sound timber is straightforward. Death watch beetle in structural oak, or anything that has weakened the wood, needs deeper or more specialised treatment.
• Treatment method. A surface permethrin spray is the standard and most economical approach. Boron gel and paste for structural timber, or fogging for widespread infestation, cost more.
• Repairs and damp. If beetle damage has gone structural, splicing, resin repair or replacing joists and rafters adds cost. Because most infestations are linked to moisture, resolving damp or rot may be needed to make the treatment last, and that is priced separately.
• Preparation and making good. Moving furniture, lifting and relaying flooring, and reinstating finishes all add to a bill.

Whatever the scope, a trustworthy firm should give you a free survey, a fixed written quote and a long-term guarantee, commonly up to 30 years, so there are no surprises once work begins.

DIY versus professional: the real cost comparison

DIY looks dramatically cheaper on paper. A five-litre tin of water-based permethrin woodworm killer costs roughly £25 to £45 and covers a useful area, so a small, accessible job might be tackled for well under £100 in materials. For a contained, correctly identified, surface-level common furniture beetle infestation in sound and accessible timber, that can be a sensible choice.

The savings narrow once you account for what DIY does not include:

• No survey or diagnosis. You are relying on your own identification and your own judgement of how far the problem extends. Misidentifying the species or the cause is an easy and expensive mistake.
• No guarantee. Professional treatment comes with a long-term, often insurance-backed warranty that satisfies surveyors and mortgage lenders. A DIY job carries no such cover, which matters at the point of sale or for a tenanted property.
• Limited penetration. Shop-bought sprays treat the surface layer well but reach structural timber poorly. Severe or deep infestations frequently need professional boron application or repair that DIY cannot deliver.
• Your time and access. Lifting floors, working in lofts safely and applying two thorough coats over a large area is real labour.

The cost of getting it wrong, such as treating dead timber, missing an underlying damp problem, or under-treating a structural infestation, can far exceed the price of a professional job done once. We weigh this up in full in our DIY vs professional woodworm treatment comparison.

How to keep costs down

You can influence the final figure without cutting corners:

• Catch it early. Acting on the first signs, before damage spreads, keeps the affected area, and the bill, smaller.
• Get a survey first. Confirming the infestation is active stops you paying to treat old, dead damage.
• Fix damp promptly. Resolving moisture issues reduces both the treatment needed and the chance of a costly recurrence.
• Combine work. If floors are already up for another reason, treating the joists at the same time saves on access labour.
• Compare written quotes. Insist on a fixed, itemised quote rather than a vague estimate, and check the guarantee terms.

For a step-by-step view of the treatment itself, our how to treat woodworm guide explains the full process, DIY and professional.

Get professional help

The only way to know what your woodworm treatment will actually cost is a proper survey of your timber. Get a free quote and a qualified surveyor will confirm whether the infestation is active, identify the beetle and give you a fixed written price, backed by a long-term guarantee, with no obligation to proceed.