Everything’s a nail to a hammer

“If the only tool you have is a hammer, it is tempting to treat everything as if it were a nail.”

This aptly describes a situation where professionals with a limited set of skills may misapply their tools to a wide range of problems. In the context of damp proofing, practitioners skilled primarily in applying damp proofing creams and impermeable slurry are often inclined to diagnose various forms of dampness at the base of a wall as rising damp. This approach can lead to misdiagnoses, as the actual causes of damp—such as condensation, penetrating damp, or leakage—require different solutions. The reliance on a singular method, regardless of the damp’s origin, underscores the need for a comprehensive diagnostic process. Identifying the correct cause of damp ensures that the appropriate, effective treatment is applied, avoiding unnecessary costs and ineffective results – see discussion on damp proofing treatment.

Law of the instrument – Abraham Maslow 1966

Background

In a Victorian property, dampness and paint discolouration ranging from the skirting board up to 1 metre on the wall, with varying tactile sensations of dampness and dryness. Notably, a contractor’s damp detector signalled readings above 60, suggesting rising damp as the culprit requiring injection treatments. Adjacent findings included damp yet visually dry plaster beneath peeled lining paper and a small patch of flaky paint without evident moisture. Furthermore, the kitchen area, previously external prior to extension, exhibited flaky, bubbling paint with reported high damp readings. This scenario underscores the challenge of diagnosing damp in aged properties, compounded by structural modifications and historical repairs.

image of the front of the Joint Position Statement RICS Historic England PCA (property care association) dated September 2022, featuring picture of drain

RICS, PCA, HISTORIC ENGLAND JPS REPORT

RICS (Royal Institute of Chartered Surveyors), Historic England (a public trust protecting sites of historic interest) and the Property Care Association (an association of mainly damp proofers) set out a Joint Position Statement (JPS), in September 2022 – see below.

There has long been disagreement about the causes of damp amongst surveyors. Historic England surveyors represent one extreme. They typically do not believe rising damp is a likely cause of internal dampness and rarely recommend altering walls to alleviate damp. By contrast PCA surveyors typically recommend rising damp treatment whenever they see dampness at the base of a wall and often recommend altering a building. RICS surveyors tend to be somewhere near the centre of these extremes. However, unlike Historic England and PCA surveyors, they rarely specialise in damp and often refer issues to PCA surveyors. We and most other independent surveyors are more closely aligned with Historic England’s position except that we are perhaps more pragmatic. For example, if a hole in the wall is the optimum way of solving internal dampness, then we will recommend it, but not otherwise.

JPS questions and answers

In addition to the content typically included in a professional and impartial survey report (e.g. client, surveyor and property details; limitations and exclusions), the report should include the following information:
1 A summary of the surveyor’s observations, including an Assessment of Significance.

dampness mainly at the base of cold walls

2 The importance of regular building maintenance and how a lack of even basic maintenance can lead to problems arising. This is especially important and relevant to roofs, gutters, hidden gutters, rainwater disposal and changes in external ground levels.

As is common with all buildings, gutters and other rainwater goods should be checked twice annually, ideally during or soon after a rainstorm, for evidence of overflow and rain not being dispersed properly from the property. You should also check that there is no flow of water flow during periods of absence for signs of a leak, for instance, by note the number on the mains water meter outside your house. external downpipe

3 An impartial diagnosis of the damp problem, which should be clearly explained and laid out systematically to communicate the relevant risks to the reader.

vapour

4 Where recommendations for the repair and recovery of moisture-affected structures are stated, the solutions should be clearly explained and prioritised as appropriate.

The solutions are explained in the Recommendations section. The primary recommendation is run a 30 litre per day dehumidifier, plus fan, target ventilation and insulate pipes.

5 The client should be provided with alternative options for which each recommendation should include advantages and disadvantages and the relevant cost and time implications.

This question is primarily directed at PCA damp proofers, to encourage them to consider methods that address the source of water not just the symptoms, such as by hacking off plaster and replacing it with slurry. You can sometimes take this damp proofing approach with short-term success. However, water will eventually find its way through. Furthermore, treatment is disruptive resulting in high cost and a poor finish, with no worthwhile guarantee of success. It likely to lower the value of the property. In our opinion you are better off trying to stop the water at its source, as we recommend. ”

6 Where monitoring and staged interventions are appropriate or beneficial, the client should be informed of the reasons for these options, together with the likely cost and time implications of such recovery strategies.

Properties should be monitored for humidity and temperature using data loggers, see datalogger section of this report. The cost of data loggers is currently less than £20 for two, aim to keep the dew point, as shown on the app screen of each logger (bottom centre on the SensorBlue), within 3°C of the external temperature, especially at night (use ventilation and/or dehumidification to reduce the internal dew point – measure external conditions or refer to weather forecasts for night-time temperatures, such as BBC Weather – a short explanation is; that this will make sure the relative humidity of all surfaces will be below the mould point even if poorly insulated). We also suggest noting values monthly using a multi-functional radio wave and conductance damp meter costing about £24 to monitor and map damp patches on internal walls. This way you can monitoring the dry progress, which typically takes 1 month per 25mm thickness of walls and more if coated. This helps determine if the root cause has been fixed or there is an additional or new source of water, and therefore more actions are required. Ideally this should be started before or soon after starting our recommendations and for about a year, repeating monthly to check progress.

7 Where appropriate, clearly state whether the building concerned represents a financial risk to the buyer or lender and why.

8 Any conflicts of interest should be clearly stated.

There is no conflict of interest. We never profit from our recommendations.

As a background, although we charge a fee for undertaking damp surveys, profit is not our primary motivator. We are motivated to:

  • solve damp problems in properties,
  • encourage clients to spend money wisely for the protection of the property and, where possible to lower the environmental impact,
  • stop or at least play our part to reduce the over-diagnosis of rising damp and so called “damp proofing” treatment by replacing plaster with chemicals and slurry, rather than dealing with the root cause.
Damp proofer Guarantee worthless
Questions and Answers
Q: How do we best redecorate the walls in the kitchen / dining room where there has been evidence of damp? For example, would you recommend a certain type of plaster, primer layer of paint and top coating of paint etc…? Anything you would avoid using?
A:Once dry, use a sand paper to remove surface salts, you may need some filler, then paint with normal emulsion.
Q: I’m sure you will already, but if not, could you please give your theories as to why the damp seemed to be concentrated to one specific area of one specific wall in the dining room (up to one metre approx.) As I have read and been told, this wall shows classic signs of ‘rising damp’ and I would like an explanation we can share if questioned by any potential buyers or surveyors in the future.
A:It’s a combination of pass, probably not very good damp proofing treatment and excess vapour. once the wall is dry, and it will take 6 to 9 months, use a damp meter to measure improvements over time, then treat as normal. Not you risk condensation coming from your neighbours side. You could encourage her to improve her ventilation. Her issue is steam from cooking condensing on a cold radiator on the other side of that wall.
Q: The insulation of the kitchen walls. I’m not 100% sure which ones you are referring to in the report. Do you mean all of the walls in the kitchen (internal and external)? Or just the ones where damp / peeling paint is evident? And as far as the insulation goes, are we talking about removing the cupboards, creating a cavity and filling that? Or is there a less invasive / disruptive option? Sorry, i’m obviously not a builder!
A:Sorry for the poor explanation. I meant specifically to insulate on the section of kitchen wall where we saw the condensation forming. This is in addition to the other recommendations. You should dry the wall out first, with a fan and reduced internal humidity. I would start with pipe insulation, then consider adding wood fibre, no one will see it so a DIY job will do, see below.
Q: I think you’ll be surprised to learn, as much as I was, that our kitchen oven extractor fan does in fact extract outside. I found the ‘tunnel’ works its way through our kitchen cupboard and there is an exit next to our kitchen window. It seems to be extracting a lot of air when on full power, too. I don’t know how I managed to miss that.
A:That is good news. Again, you need to bring the internal dew point down to the external temperature, or lower – in a perfectly ventilated property internal and external dew points will be the same, as dew point is a measure of vapour in the air. However, that is unnecessarily extreme. So long at the internal dew point is below the external temperature most of the time then you remove the risk of condensation and mould.
Q: I think you’ll also be interested to know that I removed all the skirting boards from under the kitchen cupboards and found the walls to be dry at the base – apart from the area under the sink, which you already noticed was damp from pipe condensation. If the wall is dry, it may be that you don’t need insulation, but my suspicions is the way is dry because of part damp proofing treatment.
A:Some may say this is a good reason for damp proofing a wall, but in my opinion, you are not address the root cause but the symptoms, moving the problem elsewhere, as in this case. The same can be said of insulation, that is why I say the primary solution should be to bring internal dew point down to external temperature, as a well ventilated property is, and you know that poor insulation won’t result in condensation.
Ask A.I. about your report, in the “Type your message” you could ask:

What does the damp report say are the main causes of damp and main actions to stop damp?


¿Qué dice el informe de humedad sobre las principales causas de la humedad y las principales acciones para detenerla?
潮湿报告说什么是潮湿的主要原因和防止潮湿的主要措施?
नमी की रिपोर्ट के अनुसार नमी के मुख्य कारण और नमी को रोकने के लिए मुख्य कार्य क्या हैं?
Que dit le rapport sur l’humidité concernant les principales causes de l’humidité et les principales actions pour l’arrêter?
Was sagt der Feuchtigkeitsbericht über die Hauptursachen von Feuchtigkeit und die Hauptmaßnahmen zur Bekämpfung von Feuchtigkeit?
Что говорится в отчете о влажности о основных причинах влажности и основных действиях по ее устранению?
Cosa dice il rapporto sull’umidità riguardo le principali cause dell’umidità e le principali azioni per fermarla?

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