How Much Does Dry Rot Treatment Cost?

Quick Cost Overview

• The average dry rot treatment cost in the UK ranges from £500 to £12,000+.

• Prices vary by severity, with a small localised patch at £500 - £1,500 and widespread structural damage £5,000 - £12,000+.

• The extent of the spread, from a single sill to timber and masonry throughout a property, along with how much timber needs replacing, affects the total price.

A Guide to Dry Rot Treatment Costs

In this guide, we cover:

1. What Dry Rot Is and Why Treatment Cost Varies So Much
2. What Affects the Cost of Dry Rot Treatment
3. Dry Rot Treatment Cost by Type of Work
4. Survey and Inspection Costs for Dry Rot
5. Dry Rot vs Wet Rot Treatment Cost: What's the Difference?
6. Additional Costs to Budget For
7. How to Save Money on Dry Rot Treatment
8. Signs of Dry Rot to Watch For
9. Find a Builder for a Bigger Renovation Project
10. Frequently Asked Questions

Read on for a full breakdown of dry rot treatment cost UK-wide, including the factors that push prices up and the steps that keep them down.

What Dry Rot Is and Why Treatment Cost Varies So Much

Dry rot is a wood-destroying fungus (serpula lacrymans) that attacks damp timber and, in severe cases, spreads into brickwork and plaster. Unlike wet rot, it produces fine, root-like strands called hyphae that travel through masonry in search of moisture, meaning it often causes damage far beyond the timber where it first appeared.

This is the main reason the cost of dry rot treatment fluctuates so widely between jobs: a patch confined to one windowsill costs a fraction of an infestation that has crept through a subfloor and up into a wall cavity.

Treatment cost reflects the amount of investigation, timber removal and chemical treatment needed to stop the fungus returning.

A damp proofer has to trace the fungal strands back to their source, remove every trace of affected material and treat the surrounding area with fungicide, even where the damage looks minor on the surface. That thoroughness is what separates a lasting repair from one that resurfaces within a year or two.

What Affects the Cost of Dry Rot Treatment

Several factors combine to determine how much does dry rot treatment cost for any given property, and quotes from different damp proofers often reflect different combinations of these variables. Getting familiar with them makes it far easier to compare quotes fairly.

• Severity and spread: a fresh, contained patch costs far less to treat than an infestation that has travelled through several timbers or into masonry.
• Location within the property: dry rot in a loft or under floorboards typically costs more to access and treat than rot in an open, visible area such as a skirting board.
• Accessibility: cramped roof voids, solid floors and tight wall cavities add labour time, which pushes up the overall price.
• Extent of timber replacement: the more joists, beams or floorboards need cutting out and replacing, the higher the materials and labour bill.
• Underlying cause: if the moisture source (a leaking gutter, faulty damp-proof course or condensation problem) isn't fixed at the same time, the price rises to cover that additional work.
• Property type and age: period and listed properties often need specific materials and techniques suited to older construction, which adds to the final figure.

Dry Rot Treatment Cost by Type of Work

Dry rot treatment cost breaks down into several distinct stages, and most invoices include a combination of fungicidal treatment, timber replacement and, in more serious cases, structural repair. Understanding what each stage typically costs makes a full quote much easier to interpret.

Fungicidal spray or injection treatment, used to sterilise timber and masonry that isn't beyond saving, generally forms the cheapest part of the job. Timber replacement adds more, since damaged joists, floorboards, skirting and sills have to be cut out, disposed of and replaced with new, treated timber. Where dry rot has weakened a floor, wall or roof structure, structural repair becomes the largest cost, sometimes involving a structural engineer as well as a damp proofer.

Here's a quick breakdown of what a typical job costs at each level of severity.

• Small, localised treatment (a single sill, skirting board or small patch): from £500 to £1,500
• Fungicidal spray or chemical injection treatment: roughly £70 to £100 per linear metre, materials and labour included
• Structural repair covering a single room: £1,500 to £5,000
• A full, accurate price depends on a site inspection, since the extent of hidden damage isn't visible until affected materials are opened up

Widespread Dry Rot Treatment

Widespread dry rot affecting several rooms or an entire property pushes costs considerably higher, often into five figures once timber replacement, replastering and redecoration are all included. The table below sets out average costs by job type across the range typically seen in the UK.

Job Type	Average Cost Range
Small local fungicidal treatment	£500 – £1,500
Chemical DPC injection (per linear metre)	£70 – £100
Structural repair (per room)	£1,500 – £5,000
Widespread rot (whole property)	£5,000 – £12,000+
Floor joist replacement (per joist)	£250 – £350
Severe cases with extensive structural damage	£12,000 – £20,000+

Survey and Inspection Costs for Dry Rot

A dry rot survey is the starting point for almost every treatment job, since it identifies the full extent of the problem before any work begins. Skipping this step often leads to underestimated quotes and unexpected costs once work is under way.

A standalone dry rot or timber survey typically costs between £200 and £500, with £300 being a common average for a straightforward residential inspection. Many damp proofers offer a free inspection if the survey leads directly to a booked job, so it's worth asking about this when getting quotes.

For a broader assessment covering rising damp, condensation and ventilation alongside timber health, a full damp survey cost guide explains what's included and what it costs.

A thorough survey report sets out the species of fungus involved, the extent of the spread, the likely cause and the right course of treatment. This document becomes the basis for the treatment quote, so it's a worthwhile investment even on jobs that look minor at first glance.

Dry Rot vs Wet Rot Treatment Cost: What's the Difference?

Dry rot and wet rot are often confused, but the treatment cost for each differs considerably, largely because dry rot spreads far more aggressively.

Wet rot stays localised to the timber that's directly exposed to moisture and rarely travels beyond it, while dry rot's fungal strands actively seek out new sources of damp timber and masonry to colonise.

Wet rot treatment cost UK-wide typically runs from £500 to £1,000 for minor jobs, £1,000 to £2,500 for moderate repairs involving floorboards or window frames, and upwards of £3,000 for extensive structural work. Dry rot treatment cost sits noticeably higher across every severity level, generally starting around £500 for the smallest jobs and climbing well past £10,000 for the most serious cases, reflecting the wider search-and-destroy approach needed to fully eliminate it.

The practical upshot: a damp proofer diagnosing wet rot usually recommends removing and treating the affected timber alone, while a dry rot diagnosis often means opening up surrounding walls and floors to trace the fungal growth to its source. That extra investigation work is baked into the higher average cost of dry rot treatment compared with wet rot.

Additional Costs to Budget For

Beyond the core treatment and timber replacement, several additional costs commonly appear on a dry rot repair invoice, and it's worth building these into a budget from the outset rather than treating them as a surprise later on.

• Redecoration: replastering a room averages £540 to £720, with painting adding roughly £250 to £350 per room once plaster has dried out.
• Damp-proofing works: fixing the underlying moisture problem, such as installing or repairing a damp-proof course, typically adds £500 to £1,500 depending on the length of wall treated. A full damp proofing cost guide breaks this down further.
• Ventilation improvements: adding or upgrading subfloor airbricks and vents generally costs £150 to £400 per vent, and is essential for stopping rot recurring in the same spot.
• Waste disposal: skip hire for removed timber and debris adds around £150 to £250 to most jobs.
• Structural engineer fees: for load-bearing repairs, a structural engineer's assessment adds £300 to £800 on top of the damp proofer's quote.

Budgeting an extra 15 to 20% on top of the initial quote covers most of these knock-on costs without derailing the overall project.

How to Save Money on Dry Rot Treatment

The cost of dry rot treatment drops significantly when the problem is caught early, so acting on the first signs of trouble is the single most effective way to keep the bill down. A patch spotted within weeks of appearing costs a fraction of the same patch left to spread for a year.

• Fix the moisture source straight away, whether that's a leaking gutter, damaged roof tile or poor ventilation, since dry rot returns quickly if the underlying dampness isn't resolved. This guide to spotting rising damp covers the early warning signs worth checking for around the home.
• Get at least three quotes from different damp proofers before committing, as prices for comparable jobs vary by several hundred pounds across a local area.
• Book treatment during quieter months, typically outside peak spring and summer, when damp proofers have more availability and are more open to negotiating on price.
• Bundle related work together, such as damp-proofing and redecoration, into a single job rather than booking each stage separately, since this often reduces overall labour costs.
• Read the full quote carefully to check what's included, such as waste disposal and a workmanship guarantee, so there are no unexpected add-ons once work starts.

Signs of Dry Rot to Watch For

Spotting dry rot early keeps treatment costs as low as possible, so it's worth knowing what to look for during routine checks around the home. The fungus often develops out of sight, in roof voids, under floors and behind skirting boards, before any visible signs appear in living spaces.

• A strong, musty, damp smell in a room, cupboard or loft with no obvious source.
• Timber that looks dry, cracked into cube-shaped pieces, or crumbles easily under light pressure.
• Fine, grey or white fungal strands (mycelium) spreading across timber or masonry surfaces.
• Orange-brown, pancake-shaped fungal growths (fruiting bodies), often a sign of an advanced infestation.
• Fine, rust-coloured spore dust settling on nearby surfaces, particularly beneath the fruiting bodies.
• Visible warping, sagging or bounce in floorboards, skirting or door frames.

Anyone noticing several of these signs at once benefits from booking a professional inspection quickly, since early treatment nearly always costs less than repairs carried out after months of unchecked spread. For related timber issues, a woodworm treatment cost guide covers a different but sometimes overlapping problem worth ruling out during any inspection.

Dry rot treatment cost is easiest to manage when a damp proofer is brought in as soon as the first signs appear. Posting the details of the job on MyBuilder connects the property with interested, available damp proofers who provide quotes based on the actual extent of the problem.

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Find a Damp Proofer for Your Dry Rot Treatment

Dry rot spreads quickly once it takes hold, so getting an accurate quote early on saves money in the long run. Posting a job on MyBuilder puts the details of your property in front of interested damp proofers in your area, who respond with quotes based on the specifics of your case.

All tradespeople on MyBuilder undergo checks at registration, such as ID documents, company details, certifications for regulated jobs and skill assessments, allowing you to hire with confidence.

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Frequently Asked Questions

How much does dry rot treatment cost on average in the UK?

Most homeowners pay between £500 for a small, localised patch and £6,000 for a moderate outbreak involving timber replacement and redecoration. Widespread infestations across a whole property push the total past £12,000, particularly where structural repair or listed building materials are involved.

Is dry rot treatment covered by home insurance?

Standard buildings insurance rarely covers dry rot treatment, since most policies treat it as a maintenance issue rather than sudden, accidental damage. Cover sometimes applies if the rot developed directly from an insured event, such as a burst pipe, so it's worth checking the policy wording and contacting the insurer before assuming a claim will be rejected.

Is dry rot treatable without removing the timber?

Small, early-stage patches sometimes respond to fungicidal spray or injection treatment alone, without removing the timber. Once the fungus has weakened the wood's structure, however, removal and replacement of the affected sections becomes necessary to restore safety and stop further spread.

How long does a dry rot treatment job take?

A small, localised treatment typically finishes within one to two days, while structural repair to a single room takes three to seven days. Widespread treatment across an entire property extends to two to four weeks, largely depending on how much timber needs replacing and how long plaster and materials need to dry out before redecoration.

Do I need a survey before getting a dry rot treatment quote?

A survey gives a far more accurate cost of dry rot treatment than a quote based on a visual inspection alone, since it identifies hidden damage behind walls and under floors. Most damp proofers on MyBuilder factor a survey into the process before confirming a final price, which avoids unexpected costs once work begins.

What's the difference between dry rot treatment cost and wet rot treatment cost?

Dry rot treatment cost runs noticeably higher than wet rot at every severity level, since dry rot spreads more aggressively through timber and masonry and requires wider investigation to trace fully. Wet rot treatment typically costs £500 to £3,000, while dry rot treatment ranges from £500 for minor jobs to well over £10,000 for severe, widespread cases.