Damp Proofing Cost in 2026: Surveys, Rising Damp and Repairs
The short answer
- £150 to £450 for an independent damp survey, the middle of four UK cost guides; get one before paying for treatment
- £1,800 to £2,500 to treat rising damp in a 3-bed semi with injection and replastering, or £500 to £900 for one wall
- Condensation is the commonest damp: serious condensation in 3% of homes in England, rising damp in 1%
- 10% of private rented homes had a damp problem in 2024, against 4% of owner occupied homes
Retrofit Planner's comparison of five UK cost guides puts an independent damp survey at £150 to £450 and rising damp treatment for a 3-bed semi, a chemical damp proof course with replastering, at £1,800 to £2,500 in 2026. A terrace costs about £1,000 to £1,500 and a detached house £2,500 to £5,000; treating a single wall costs £500 to £900. There is no free official price data for damp work, so every range here is the middle half of the published prices, shown side by side below. Before paying for any of it, find out what kind of damp you have. Government survey data shows serious condensation in 3% of homes in England and rising damp in 1%, and condensation is cured with heat and ventilation, not injections.
Damp survey cost
An independent damp survey costs about £150 to £450, the middle half of four UK cost guides. A "free" survey from a damp proofing company costs nothing, but the firm that surveys is also the firm that sells the treatment.
| Survey | Typical cost | Who does it |
|---|---|---|
| Independent damp survey | £150 to £450 | A damp surveyor or building surveyor with nothing to sell |
| Survey by a damp proofing company | Free, or £150 to £350 | The contractor who would do the work |
| Damp and timber report before buying | £250 to £500 | A damp and timber surveyor |
| RICS HomeBuyer Report (whole house) | £400 to £700 | A RICS surveyor; it flags damp but does not diagnose it in depth |
The data behind this table
Independent survey: the middle half of the ranges given by BestBuilders (£150 to £500), Trade2Base (£150 to £400), Less.co.uk (£250 to £450) and HaMuch (£150 to £600), rounded to the nearest £50. MyJobQuote does not price a survey. Contractor survey: Trade2Base (£150 to £350); BestBuilders and Less.co.uk list the free kind. Pre-purchase report: BestBuilders. HomeBuyer Report: Less.co.uk. All read on 11 November 2026.
Read the detail
Size matters a little. BestBuilders prices an independent survey at £150 to £250 for a 2-bed flat, £300 to £400 for a 3-bed house and £450 to £600 for a 4-bed detached house. Less.co.uk puts it at about half a day's work.
A good survey looks for where the water is coming from, not just where it shows. In 2022 RICS, Historic England and the Property Care Association published a joint position statement on investigating moisture in traditional buildings. It asks surveyors to take a "whole building" approach, to look for the source of any excessive moisture and not to rely on potentially misleading data. Ask any surveyor whether they follow it. Trade2Base says a surveyor who recommends injection after a brief visit with only a moisture meter has not carried out a proper survey.
BestBuilders flags a contractor's free survey as not impartial, and Trade2Base lists "free survey" offers among its warning signs. Neither means every free survey is wrong, but paying a few hundred pounds for an independent view can save several thousand on the wrong treatment.
Damp proofing cost by house type
Treating rising damp with a chemical damp proof course and replastering costs about £1,000 to £1,500 for a terrace, £1,800 to £2,500 for a 3-bed semi and £2,500 to £5,000 for a detached house. The length of wall treated and the amount of plaster to replace decide most of the difference.
| House | Damp proof course and replastering | Spread across the guides |
|---|---|---|
| Terrace, 2 to 3 bed | £1,000 to £1,500 | £250 to £2,800 |
| Semi-detached, 3 bed | £1,800 to £2,500 | £475 to £4,500 |
| Detached, 3 to 4 bed | £2,500 to £5,000 | £690 to £5,500 |
The data behind this table
The middle half of the house type prices published by MyJobQuote, BestBuilders, Trade2Base, Less.co.uk and HaMuch, read on 11 November 2026, rounded to the nearest £100 (see "How we work out our range" below). BestBuilders, Trade2Base and Less.co.uk include replastering. MyJobQuote's house type figures cover all damp proofing jobs, from one wall to the whole house, which is why its low ends are so low. HaMuch gives a single average for injection damp proofing. The spread is the cheapest and dearest figure any of the five gives.
Read the detail
A mid-terrace usually needs only its front and rear walls treated, because the party walls are shared and sheltered, which is how Trade2Base and Less.co.uk price it. A semi adds a side wall, and a detached house has four exposed walls. BestBuilders prices by the length of wall: 10 to 16 metres for a small terrace, 16 to 24 metres for a 3-bed semi and 24 to 36 metres for a 4-bed detached house.
Replastering is often the bigger part of the bill. After an injection, the old plaster, which holds salts drawn out of the wall, is hacked off to about a metre high and replaced with a salt-resistant render. The guides price that at £30 to £80 per m² on top of the injection.
Region matters too. Less.co.uk puts London 17% above the UK average and the North East and Yorkshire 11% below it; Trade2Base puts London and the South East typically 20 to 30% higher; BestBuilders puts inner London 20 to 25% higher and the North and Scotland 5 to 10% lower.
Rising damp treatment cost, line by line
Chemical injection costs £70 to £120 per metre of wall, and treating one wall with replastering about £500 to £900. Four of the five guides give the same per metre rate.
| Item | Typical cost |
|---|---|
| Chemical damp proof course, injected | £70 to £120 per metre |
| One wall, injection and replastering | £500 to £900 |
| Salt-resistant replastering | £30 to £80 per m² |
| New skirting boards | £8 to £15 per metre |
| Redecorating after drying out | £300 to £800 per room |
| DIY injection kit | £30 to £100 |
The data behind this table
Per metre: BestBuilders, Trade2Base and Less.co.uk (£70 to £120 each) and HaMuch (£100). One wall: the middle half of MyJobQuote (£560 to £2,200), BestBuilders (£600 to £1,200), Less.co.uk (£350 to £700) and Trade2Base (£280 to £480 to inject a 4 m wall plus £160 to £320 to replaster 4 m², which we added together), rounded to the nearest £100. Replastering: BestBuilders (£30 to £70), Trade2Base and Less.co.uk (£40 to £80). Skirting and redecorating: Less.co.uk. DIY kits: Less.co.uk (£30 to £80) and BestBuilders (£30 to £100). Read on 11 November 2026.
Read the detail
A chemical damp proof course is a line of holes drilled into the mortar just above ground level and filled with a water-repellent cream, which forms a barrier against moisture rising from the ground. Less.co.uk puts the injection at 1 to 3 days for a specialist and the replastering at 2 to 4 days. Trade2Base says to wait at least 3 to 6 months before redecorating, while the wall dries, and that guarantees on a chemical damp proof course usually run 20 to 30 years.
Trade2Base also notes that rising damp usually climbs no higher than about 1.2 to 1.5 metres. Damp higher up a wall, or upstairs, has another cause.
What five cost guides say
Published prices for treating rising damp in a 3-bed semi run from £475 to £4,500. Our range is the middle half of every figure the five guides give, which sets aside the cheapest and the dearest.
| Guide | 3-bed semi, whole house | One wall | Independent damp survey |
|---|---|---|---|
| MyJobQuote, updated 2 January 2026 | £475 to £2,350 (all damp proofing jobs) | £560 to £2,200 (injection) | Not given |
| BestBuilders, updated 29 August 2026 | £1,800 to £3,800 (with replastering) | £600 to £1,200 (with replastering) | £150 to £500 |
| Trade2Base, 8 June 2026 | £1,000 to £2,500 (with replastering) | £280 to £480 for 4 m, injection only | £150 to £400 |
| Less.co.uk, updated 4 November 2026 | £2,000 to £4,500 (with replastering) | £350 to £700 | £250 to £450 |
| HaMuch, updated 11 March 2026 | £2,500 (average, injection) | Not given | £150 to £600 |
| Our range: the middle half | £1,800 to £2,500 | £500 to £900 | £150 to £450 |
The data behind this table
Read on 11 November 2026. Trade2Base says its rising damp prices leave out VAT; BestBuilders' page says both that its prices include VAT and that they exclude it; HaMuch's regional table leaves VAT out and its main table does not say; MyJobQuote and Less.co.uk do not say. BestBuilders says its ranges come from registered damp specialists, trade cost data and homeowners' quotes; Less.co.uk from trade rate cards and supplier prices; HaMuch from its tradespeople's rates. MyJobQuote and Trade2Base do not publish a method. Checkatrade's damp proof course page refused our request, so its figures are not in the table.
Read the detail
All five guides come from websites that match homeowners with tradespeople or sell leads to them. None is a survey of finished jobs, so treat every figure as a guide price. The main reason they disagree is what they include: MyJobQuote's house type figures cover every kind of damp job, from a single wall to the whole house, while BestBuilders, Trade2Base and Less.co.uk price a full treatment with replastering. Less.co.uk's typical 3-bed semi is £3,000, above our range, and MyJobQuote's average rising damp job is £3,250.
How we work out our range
For each column we put every published figure into one list: both ends of a range, or the single average where that is all a guide gives. Our range is the middle half of that list, from its lower quartile to its upper quartile, rounded to the nearest £100 (the nearest £50 for surveys). For a 3-bed semi the list is £475, £1,000, £1,800, £2,000, £2,350, £2,500, £2,500, £3,800 and £4,500, which gives £1,800 to £2,500. For one wall it is £350, £440, £560, £600, £700, £800, £1,200 and £2,200, which gives £500 to £900; Trade2Base's two figures are its injection and replastering prices added together. For a survey it is £150, £150, £150, £250, £400, £450, £500 and £600, which gives £150 to £450. A single unusually high or low guide moves the range very little.
Is it damp or condensation?
Look at where the damp is and when it gets worse. Mould in corners and wet windows in cold weather point to condensation; a patch that grows after rain points to penetrating damp; a tide mark low on a ground floor wall may be rising damp.
| What you see | Most likely cause | First fix and typical cost |
|---|---|---|
| Wet windows, black mould in corners, behind furniture or in the bathroom; worse in winter and in the morning | Condensation | Heat and ventilate: £100 to £400 for an extractor fan, £250 to £1,200 for a PIV unit. See our condensation and mould guide |
| A patch on an outside wall, at any height, that grows after rain; often near a gutter, downpipe, sill or cracked render | Penetrating damp | Repair the outside: £80 to £800 for gutters or pointing, £300 to £3,000 or more for wider repairs |
| A tide mark low on ground floor walls, up to about 1.2 to 1.5 metres, with salty or crumbling plaster or rotting skirting | Rising damp, or soil, a path or render bridging the damp proof course | Check for bridging first: £100 to £500 to lower the ground or cut back render. A new damp proof course only if the old one is missing or failed |
| Damp below a bathroom, round pipes or on a ceiling, whatever the weather | A plumbing or roof leak | A plumber or roofer; see our roof replacement guide |
| Wet cellar or basement walls | Ground water pushing through below ground | Tanking: £2,000 to £20,000 or more depending on size |
The data behind this table
The signs are the usual ones the cost guides and our condensation guide describe; a survey is the way to be sure. Costs are the spread across the guides that price each fix, read on 11 November 2026: extractor fans, Trade2Base (£100 to £250) and BestBuilders (£250 to £400, with a humidity sensor); PIV units, Less.co.uk (£250 to £500), Trade2Base (£400 to £700) and BestBuilders (£400 to £1,200); gutters and pointing, Less.co.uk (£80 to £250 for gutters) and BestBuilders (£150 to £800); wider penetrating damp repairs, BestBuilders (£300 to £3,000 or more) and Less.co.uk (£400 to £1,500); bridging, BestBuilders; tanking, Trade2Base, BestBuilders and Less.co.uk (see the cellar row in the costs table below).
Read the detail
Condensation forms when warm, moist air from cooking, washing and breathing meets a cold surface. It shows first on windows, in the corners of outside walls and behind wardrobes, and it is usually worst on cold mornings. Our condensation and mould guide explains the fixes in order: heating, ventilation and insulation.
Penetrating damp is rain getting through the wall or roof, so it follows the weather and can appear at any height. The English Housing Survey links it to defects on the outside of a home, such as broken gutters, failed pointing or cracked render.
Rising damp is ground water drawn up a wall where a damp proof course is missing or in disrepair, as the English Housing Survey puts it. It stays low on ground floor walls and often leaves a salty tide mark. A working damp proof course can also be bypassed, or "bridged": by a flower bed or patio built up above it, by render taken down to the ground, or by rubble in the cavity. Clearing the bridge is often all that is needed, and costs far less than a new damp proof course.
Why so much damp is not rising damp
In 2024 government surveyors found serious condensation in 3% of homes in England, penetrating damp in 2% and rising damp in 1%. Rising damp is the rarest of the three, and the only one a damp proof course treats.
| Type of damp | Share of homes, 2024 | The usual fix |
|---|---|---|
| Serious condensation or mould | 3% | Heating, ventilation, insulation |
| Penetrating damp | 2% | Outside repairs: gutters, pointing, render |
| Rising damp | 1% | Clear bridging; a damp proof course if it is missing or failed |
The data behind this table
English Housing Survey 2024 to 2025, Chapter 1: Housing quality (MHCLG, 29 January 2026), Annex Table 1.10. Surveyors record damp only when it is significant, so minor damp is not counted, and a home can have more than one type. The same chapter gives rising damp as 1.5% in its trend figures, up from 1.0% in 2019.
Read the detail
The gap between what people notice and what surveyors find is wide. In 2024, 30% of households told the English Housing Survey their home had problems with condensation, damp or mould, but only 13% of those households lived in a home where the surveyor recorded a damp problem. Much of what people see is condensation that comes and goes, which surveyors do not count unless it is serious.
The industry's own guides say the same thing. MyJobQuote's rising damp page warns that damp is very often misdiagnosed, and BestBuilders argues that more money is lost to misdiagnosis than to overpriced work. The 2022 joint position statement from RICS, Historic England and the Property Care Association exists for the same reason: it asks surveyors to find the source of moisture with a whole building approach rather than treat a meter reading as a diagnosis.
If you are told you have rising damp, ask what else was ruled out, how, and whether the ground outside sits above the damp proof course.
Penetrating damp, condensation and cellar costs
Most fixes for penetrating damp and condensation cost less than a damp proof course: gutter repairs from £80 and a PIV unit from £250. Tanking a cellar is the exception, at £2,000 or more.
| Fix | What the guides say |
|---|---|
| Gutter or downpipe repair | Less.co.uk £80 to £250; BestBuilders £150 to £800 including pointing |
| Repointing brickwork | Trade2Base £15 to £25 per m²; Less.co.uk £30 to £60 per m² |
| Penetrating damp repair, wider | Less.co.uk £400 to £1,500; BestBuilders £300 to £3,000 or more |
| Lowering ground or cutting back render that bridges the damp proof course | BestBuilders £100 to £500; clearing air bricks £0 to £150 |
| Extractor fan, fitted | Trade2Base £100 to £250 per fan; BestBuilders £250 to £400 with a humidity sensor |
| Positive input ventilation (PIV) unit, fitted | Less.co.uk £250 to £500; Trade2Base £400 to £700; BestBuilders £400 to £1,200 |
| Dehumidifier | Trade2Base £150 to £350 to buy and about £100 to £200 a year to run |
| Cellar or basement tanking | Less.co.uk £2,000 to £6,000; BestBuilders £4,000 to £14,000; Trade2Base £2,000 to £5,000 for a small cellar and £8,000 to £20,000 or more for a full basement |
| Wet or dry rot found in timbers | Trade2Base £300 to £800 per area of wet rot and £500 to £1,500 for isolated dry rot; Less.co.uk £500 to £2,000 |
The data behind this table
Each guide's own figures, read on 11 November 2026. The guides price these fixes too differently to combine, so we show them side by side. MyJobQuote prices drainage channels round a house at £380 to £1,400, a way of lowering wet ground against the walls.
Read the detail
For condensation, the cheapest fixes come first: keep rooms steadily warm, use the extractor fans you have, dry washing outside or in a ventilated room and keep furniture off cold outside walls. A PIV unit, which blows filtered air from the loft into the house, is the usual next step; BestBuilders puts its running cost at about £35 a year.
For penetrating damp, a roofer, builder or gutter firm is usually the right trade, not a damp proofing company. Once the leak is fixed, the wall needs time to dry before you replaster or redecorate.
Which homes have damp
In 2024, 5% of homes in England, 1.4 million, had a damp problem: 10% of private rented homes, 7% of social rented homes and 4% of owner occupied homes. Homes built before 1919 are the most likely to be damp.
| Tenure | Any damp problem | Rising damp | Penetrating damp | Serious condensation |
|---|---|---|---|---|
| Private rented | 10% | 3% | 4% | 6% |
| Social rented | 7% | 1% | 2% | 5% |
| Owner occupied | 4% | 1% | 2% | 2% |
| All homes | 5% | 1% | 2% | 3% |
The data behind this table
English Housing Survey 2024 to 2025, Chapter 1: Housing quality (MHCLG, 29 January 2026), Annex Tables 1.9 and 1.10. Within social renting, 8% of council homes and 6% of housing association homes had damp. The figures by age come from the English Housing Survey local authority housing stock condition modelling, 2023 (28 May 2025), for 2022, and the regional figures from the 2024 edition (25 June 2026).
Read the detail
Age matters most. In 2022, 10% of homes built before 1919 had a damp problem, against 1 to 4% of homes built in later periods. Older homes have solid walls, older or no damp proof courses and more exposed detail to fail, and the private rented sector holds more of them, which is part of why it has the most damp.
Damp has been rising since 2019: from 2022 to 2024 it rose from 2% to 4% of owner occupied homes and from 5% to 7% of social rented homes. The government's 2024 modelling found more than 6% of homes with damp in the East Midlands, London, the North West and Yorkshire and the Humber, and homes in the wettest areas slightly more likely to be damp (7%) than those in the driest (5%). In 97% of local authorities, fewer than 10% of homes are estimated to have damp.
Awaab's Law and landlords' duties
Since 27 October 2025, social landlords in England must investigate significant damp and mould within 10 working days and make the home safe within 5 working days of the investigation. Emergency hazards must be dealt with within 24 hours.
| Step | Time limit |
|---|---|
| Emergency hazard: investigate and make safe | Within 24 hours |
| Significant damp or mould: start investigating | Within 10 working days of being told |
| Written summary of findings to the tenant | Within 3 working days of the investigation finishing |
| Make the home safe | Within 5 working days of the investigation |
| Further repair work | Must begin within 12 weeks at the latest |
| Home cannot be made safe in time | Landlord must offer suitable alternative accommodation |
Where these rules come from
Awaab's Law: Guidance for tenants in social housing (MHCLG, updated 4 December 2025) and the government announcement of 27 October 2025, when the rules came into force for social housing in England. The announcement says a second phase in 2026 adds hazards such as excess cold and heat, fire, electrical risks and hygiene, and a third in 2027 the remaining hazards in the Housing Health and Safety Rating System except overcrowding.
Read the detail
Awaab's Law applies to most social housing tenancies in England. If you rent from a council or housing association, report damp or mould to your landlord through its official channels, and keep a record of every report and reply.
Private renters are not covered yet. The government has committed to extending Awaab's Law to the private rented sector through the Renters' Rights Bill, which completed its passage through Parliament on 22 October 2025; check gov.uk for when it starts to apply to private tenancies. Private tenants should still report damp to their landlord in writing, and can contact the council if it is not dealt with. Landlords can find what the law already asks of them in Landlord Planner's Awaab's Law and damp guide.
For a landlord, the order of costs matters. An independent survey at £150 to £450 that finds condensation leads to fans and heating, not a damp proof course, and a written diagnosis is a record of having investigated.
Damp, insulation and heating
Fix the source of damp before you insulate a wall, and expect insulation and steady heating to cut condensation. Insulation keeps inside surfaces warmer, so less moisture settles on them.
Read the detail
Damp and energy are linked both ways. A cold home grows more condensation, so heating and insulation are part of the cure for the commonest kind of damp, as our condensation guide explains. A wet wall, on the other hand, should be dried and its leak or bridge fixed before anything covers it, or the moisture is sealed in.
That matters most for older homes with solid walls, the homes most likely to be damp. If you are planning solid wall insulation, ask the installer how the wall will be kept dry and ventilated, and deal with gutters, pointing and ground levels first. For underfloor insulation on a suspended timber floor, keep the air bricks clear, because they keep the timbers dry.
How to get quotes
Get the cause diagnosed first, then at least three itemised quotes for the same work. A quote for a damp proof course should say in writing why rising damp is the cause.
Read the detail
- Pay for an independent survey before any treatment. Trade2Base suggests a surveyor holding the CSTDB damp and timber qualification or a RICS consultant.
- Ask the surveyor what caused the damp, what else was ruled out and how, and whether any soil, path or render bridges the damp proof course.
- Ask for each line priced separately: the survey, the injection by the metre, hacking off and replastering by the square metre, skirting, skips and redecoration.
- Ask what plaster will be used. After an injection it should be a salt-resistant render, not ordinary gypsum plaster.
- Ask about the guarantee and whether it is insurance-backed if the firm stops trading; BestBuilders puts the premium at about 3 to 5% of the job.
- Ask how long to wait before decorating; Trade2Base says 3 to 6 months.
We do not recommend damp proofing firms yet, and no link on this page is paid. When we do, every firm will have to meet our trusted supplier standard.
Frequently asked questions
How much does damp proofing cost?
Treating rising damp with a chemical damp proof course and replastering costs about £1,800 to £2,500 for a 3-bed semi in 2026, the middle half of the prices five UK cost guides publish. Expect about £1,000 to £1,500 for a terrace and £2,500 to £5,000 for a detached house. Many damp problems need a cheaper fix, such as gutter repairs or better ventilation, so get the cause diagnosed first.
How much does a damp survey cost?
An independent damp survey costs about £150 to £450, the middle half of four UK cost guides, or roughly £300 to £400 for a 3-bed house on BestBuilders' figures. Damp proofing companies often survey for free, but they also sell the treatment, so an independent survey is the safer first step.
How much does rising damp treatment cost?
Chemical injection costs £70 to £120 per metre of wall, and treating one wall with replastering costs about £500 to £900. A whole 3-bed semi costs about £1,800 to £2,500. Allow 3 to 6 months for the walls to dry before redecorating.
How can I tell if it is damp or condensation?
Condensation shows as wet windows and black mould in corners, behind furniture and in bathrooms, and is worst in cold weather. Penetrating damp is a patch on an outside wall that grows after rain. Rising damp leaves a tide mark low on ground floor walls, usually no higher than about 1.2 to 1.5 metres. An independent survey is the way to be sure.
Is rising damp often misdiagnosed?
It can be. In 2024 government surveyors found serious condensation in 3% of homes in England and rising damp in 1%, and cost guides including MyJobQuote and BestBuilders warn that damp is often misdiagnosed. A joint statement from RICS, Historic England and the Property Care Association asks surveyors to find the source of moisture rather than rely on misleading readings.
What does Awaab's Law mean for damp and mould?
Since 27 October 2025, social landlords in England must investigate significant damp and mould within 10 working days, give the tenant a written summary within 3 working days of the investigation and make the home safe within 5 working days. Emergency hazards must be dealt with within 24 hours. The government has committed to extending it to private renting.
Data sources
Updated 11 November 2026.
Prices come from five UK cost guides, read on 11 November 2026. How common damp is comes from the English Housing Survey, landlords' duties from gov.uk, and the advice on diagnosis from RICS, Historic England and the Property Care Association.
Show every source
Damp proofing prices: MyJobQuote, Rising damp treatment cost (updated 2 January 2026); BestBuilders, Damp proofing cost UK (updated 29 August 2026); Trade2Base, Damp proofing costs UK (8 June 2026, VAT excluded on rising damp prices); Less.co.uk, Damp proofing cost UK 2026 (updated 4 November 2026); HaMuch, Damp proofing cost (updated 11 March 2026). All read on 11 November 2026.
How common damp is: English Housing Survey 2024 to 2025, Chapter 1: Housing quality (MHCLG, 29 January 2026); English Housing Survey: local authority housing stock condition modelling, 2024 (MHCLG, 25 June 2026); English Housing Survey: local authority housing stock condition modelling, 2023 (MHCLG, 28 May 2025).
Landlords' duties: Awaab's Law: Guidance for tenants in social housing (MHCLG, updated 4 December 2025) and Millions of tenants safe from black mould through Awaab's Law (gov.uk, 27 October 2025). Diagnosis: Investigation of moisture and its effects on traditional buildings (joint position statement, RICS, Historic England and the Property Care Association, 2022). Full method on our methodology and data sources pages.