Is rising damp a myth?

So is rising damp real?

Yes, but it is one of the less common kinds of damp. UKHSA and DHSC guidance lists rising damp among the four main types, alongside condensation, penetrating damp and water from leaks or flooding. SPAB, often seen as the sceptical voice, also says rising damp is real, while adding that it is rarer than assumed and often misdiagnosed.

The national survey supports both points. In the English Housing Survey's surveyor-assessed figures for 2024, rising damp was found in 1% of homes in England, against 2% for penetrating damp and 3% for serious condensation and mould. It exists, and it is outnumbered.

What does the 2022 Joint Position Statement say?

That damp should be investigated by cause, step by step, before anything is sold. In September 2022 RICS, Historic England and the Property Care Association published a joint position statement on investigating moisture in traditional buildings. Cadw, Historic Environment Scotland, Northern Ireland's Historic Environment Division, the IHBC and SPAB have adopted it.

It calls for a non-invasive inspection first, with invasive investigation only if needed, and diagnosis that deals with causes rather than symptoms. It says work is often staged: fix obvious defects, allow time for monitoring and drying, then reassess. Surveyors should consider ventilation, ground levels, drainage, how the building is used, maintenance and past alterations, and it says moisture in an older building does not automatically mean a construction fault.

It also says reports should be objective, and that any remedy quoted should not financially benefit the surveyor or their firm unless that is declared. The statement does not mention chemical damp-proof courses or any other product, for or against.

Why do surveyors say rising damp is overdiagnosed?

Because they keep finding damp courses sold for problems with other causes. The RICS consumer guide says rising damp is "often misdiagnosed", that failure of an original damp-proof course "is extremely rare", and that wrongly blaming it leads to unnecessary replacement.

A November 2026 RICS building pathology article says many properties receive unnecessary chemical damp courses while the real moisture source remains, so the damp and mould return. It describes a case diagnosed as a failed damp course where a high patio outside was bridging it, and warns of a conflict of interest when the firm diagnosing the problem also sells the remedy.

Which? reports that its investigation revealed bad practice from a number of specialist damp companies, and notes that rising damp can be the most expensive type to fix yet is one of the least common. BRE Digest 245 adds that an existing physical damp course is rarely faulty, although debris in a cavity can bridge it.

What does SPAB say about older houses?

That there should be a presumption against retrofit damp courses in buildings from before about 1919. SPAB says they can be damaging, ineffective and costly in such buildings, with exceptions where alterations have made an old building behave like a sealed modern one.

Its alternatives start outside: SPAB's technical director lists defective roofs, poor rainwater goods and plumbing leaks, cement repairs letting water into hairline cracks, and ground levels raised too high. SPAB says hard cement render can stop a wall drying, and that lime repointing or removing the render may be the better fix.

It also notes that mortgage lenders sometimes demand damp-proofing that is not needed, and recommends a written second opinion from an independent chartered surveyor or consultant rather than a contractor. Treat the 1919 figure as SPAB's guide rather than a legal cut-off.

What does the damp-proofing industry say?

That rising damp exists, and where it is confirmed, a new damp-proof course is the remedy. The PCA Code of Practice (2017) says rising damp can only be controlled by a new damp-proof course. It notes that BRE recommends alternative methods only if they have third-party accreditation, that injected damp courses are the only method cited as meeting that, and that electro-osmosis lacks British third-party accreditation.

On that point SPAB agrees: where a physical damp course is not feasible, it follows BRE in accepting only certified methods, and says chemical injection is currently the only one that qualifies. The British Standard for this work, BS 6576, covers both diagnosis and installation and stresses telling rising damp apart from other causes.

The PCA Code also says surveyors should check whether an existing damp course has been bridged or buried before anything else, and that internal waterproofing is not recommended as a primary or long-term remedy for rising damp.

Can a damp course make things worse?

It can if it is the wrong fix or is combined with the wrong work. The RICS pathology article warns against pairing a retrofit chemical damp course with wall insulation, which can trap moisture in the wall. Historic England says impervious renders on traditional walls can trap water behind them, keeping the wall saturated.

Even where injection is right, the finish matters. The PCA Code says impervious coatings should not go on until walls have dried, which may take 1 to 12 months or longer.

Where do both sides agree?

On the order of work: diagnose first, fix the obvious defects, monitor, and treat what is left. Conservation bodies and the industry code both start by checking for bridged damp courses, high ground, leaking gutters and condensation before any wall is drilled.

That is the approach behind damp proofing in Stafford from Stafford Damp Proofing. A damp survey looks for the cause, and rising damp treatment is recommended only where the evidence points to ground moisture. Our guide on rising damp or condensation covers the tests, and the cost guide shows why getting it right first time matters.

Questions we get asked

My mortgage lender wants a damp course. What can I do?

SPAB suggests a written second opinion from an independent chartered surveyor or consultant if you doubt the work is needed. Ask for the evidence behind the recommendation before agreeing to anything.

Is chemical injection a con?

No. Where rising damp is confirmed and a physical damp course is not practical, SPAB and the PCA both point to injection as the only method with third-party certification. The problem is using it where the damp has another cause.

Who should I ask for a second opinion?

SPAB recommends an independent chartered surveyor or consultant rather than a contractor. RICS adds that membership alone does not prove damp expertise, so ask about building pathology experience.

Where these facts come from

• GOV.UK: Understanding and addressing the health risks of damp and mould in the home (first published 7 Sep 2023, updated 1 Apr 2026)
• SPAB: What is rising damp?
• GOV.UK: English Housing Survey 2024 to 2025, housing quality (29 January 2026)
• RICS, Historic England and the PCA: investigation of moisture in traditional buildings, joint position statement (September 2022)
• Cadw: Investigation of moisture and its effects on traditional buildings
• RICS: damp and mould, a consumer guide (16 June 2025)
• RICS Built Environment Journal: Understanding dampness: a pathological approach (5 Nov 2026)
• Which?: damp-proofing companies (page dated 5 May 2026)
• BRE: Rising damp in walls, diagnosis and treatment (Digest 245, 2007)
• Homebuilding & Renovating: how to treat damp in older houses, by SPAB's technical director (updated 8 April 2024)
• Property Care Association: Code of Practice for the investigation and control of dampness in buildings (March 2017)
• BSI: BS 6576, diagnosing rising damp and installing chemical damp-proof courses
• Historic England: Risks of energy efficiency interventions