Is this what passes for a survey and damp proofing report?

How damp proofers sell unnecessary DPC injection work. 

Typical of the Reports used by the damp proofing industry to sell unnecessary retrofit DPC injection work and re-plastering.

Fig 1. Typical of the Reports used by the damp proofing industry to sell unnecessary retrofit DPC injection work and re-plastering.

We’ve had to do one inspection this week and one detailed survey relating to production of a Part 35 compliant expert witness report; in both cases this involved checking a survey Damp proofing report that were recently provided by an East Midlands damp proofing company, Preserva. Our last involvement with this company was when we were called to re-survey a property in Nottingham after the same company had diagnosed rising damp and hacked off all the low level plasterwork from the clients walls up to waist height. It was at this point the client got suspicious and called us in. What we found was that this company had done no diagnostic work to prove that rising damp was present, they further stated that a damp proof course comprised of blue engineering bricks had failed and failed to point out where the damp proof course was bridged by soil banked against the wall. We did the diagnostic work and in fact proved that the property did not have rising damp, or indeed any significant moisture present at depth in the masonry. The property was suffering from chronic condensation damp and we specified works to deal with this issue. Preserva reinstated the plasterwork at their own expense and my client saved circa £2500 by not having unnecessary remedial treatment carried out for rising damp.

Qualifications

We’ve said this before but if you invite a CSRT ‘qualified surveyor’ into your home then you invite a chemical  salesman into your home. It took me many years to get letters after my name, whereas the CSRT (Certificated Surveyor in Remedial Treatment) can be achieved in three days with no previous experience of buildings or surveying, but apparently after three days they are now experts in damp.

It would appear that nothing has changed because again we reviewed two recently completed reports that fail to prove the cause of damp and make incredibly tenuous claims that rising damp is present. Lets analyse the first one…

Despite damp proofers specifying remedial work for rising damp, there was no significant moisture present at depth.

Despite damp proofers specifying remedial work for rising damp, there was no significant moisture present at depth.

In fact the 8 page ‘report’ is fairly standard generic text with a few comments inserted to vaguely satisfy the unsuspecting public that they have diagnosed rising damp; though they stop short of ever saying this, which is a feature we’ve found in all their reports, that we’ve reviewed. In this report their CSRT ‘qualified’ surveyor makes the following statement… “At the time of our inspection visible signs of dampness, supported by moisture profile readings obtained using an electronic moisture meter, indicated the presence of dampness to all accessible ground floor walls. This is apparently due to salt contaminated plasterwork and an apparent possible breakdown of any existing damp proof course.”

Never has the word apparent been more incorrectly used because quite clearly it wasn’t apparent since no diagnostic work had been done. The ‘surveyor’ had not carried out salts analysis to prove that salts were present in the plasterwork and in fact there was no salt migration visible on inspection of the plasterwork. Additionally, he had not carried out testing to prove that moisture was present at depth in the masonry; this is a pre-requirement before even suggesting that the existing damp proof course has failed.

Incidentally, damp proof courses do not fail, please read this… http://buildingdefectanalysis.co.uk/conservation/do-physical-damp-proof-courses-fail/

He briefly discusses moisture profiles despite the fact that you cannot obtain any useful moisture profiles using an electronic moisture meter and further fails to even mention what that moisture profile is! Is it a rising damp moisture profile, a reverse rising damp moisture profile or just a random profile? We’ll never know but since he specified unnecessary remedial work for rising damp then I think we can assume it was a rising damp moisture profile. Critically, since it was only a relative reading then the results are unreliable and more importantly they are only moisture profiles at the wall surface. Even scan meters can not provide useful or reliable moisture profiles at depth in the masonry, and this is what we are fundamentally concerned with when investigating the potential for rising damp. The unnecessary work quoted for as a result of this report would have cost the client £2996.00 plus vat and to add insult to injury they were expected to pay £75.00 for an insurance backed guarantee if they wanted optional long term protection on this unnecessary work.

Second Review

Our second review concerns a property in Derbyshire that was surveyed by Preserva in December 2015. Their observations are limited to the following internal observations, ” Chimneys were open encouraging direct rainfall to enter the building fabric. These should be capped with a vented cowl by your builder. External brickwork was very porous and was rendered on the front and gable ends. This render was in a poor condition and it was suggested that this should be removed. The property did not appear to have been constructed with any sort of damp proof course.” 

In fact these are reasonable but limited comments and whilst it’s reasonable to comment that buildings don’t have an existing physical DPC, this was not entirely true. The rear extension in fact had a physical DPC comprising of blue engineering bricks and there were a large number of other external damp related defects that were not commented on; probably because they would not facilitate the sale of retrofit chemical injection. The main part of the building may not have a physical DPC, none was visible. However buildings can manage moisture perfectly well without a physical damp proof course and in fact there are thousands of buildings in the UK that do not have a physical damp proof course but do not have a problem with rising damp.

Internal observations were limited to the following, “Dampness was noted around all external walls of the dining room and lounge areas. Moisture profiles taken with a moisture meter confirmed that dampness was a problem within these walls. This was clearly due to the defects noted above and could also be attributed to some rising moisture from the ground also.” 

Timber moisture content of 26% means that timbers are at risk of timber decay.

Timber moisture content of 26% means that timbers are at risk of timber decay.

The operative word here is “could”… works were specified for rising damp on the basis that some dampness could be attributed to rising moisture from the ground, so again we see an assumption being made in the complete absence of any credible diagnostic results. Moreover, there were internal issues that would have been obvious to any reasonably competent surveyor, not least of which was incredibly high moisture content to the timber floor joists in the cellar. We do not know what the value of this work was but you can be sure that it was a substantial sum, we rarely see quotes of less than £2.5k for this sort of unnecessary work and frequently quotes are substantially higher. We have not yet encountered a case where the work has been required.

Also please read http://buildingdefectanalysis.co.uk/damp/diagnosing-rising-damp/

Damp Proofing is Almost Never Required! 

 

We’ll say it again… ‘Specialist treatments for damp are almost never required and the vast majority of damp can be cured with nothing more than minor and often inexpensive building works.’

You should view any report you receive from a damp proofing company with extreme scepticism.

 

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11 Comments

  • Julie Dunnon

    Trying to sell our house. After a building survey, the buyer commissioned a CSRT surveyor to assess any damp problems. Despite plasterwork being perfect, no signs of damp, we were told we had rising damp in the older parts of our 1930s house as indicated by his moisture meter. He claimed that our skirting boards, (in perfect condition), would need to be removed, cavity wall insulation removed, a lower course of bricks near the dpc removed from outside to assess the alleged ‘rising damp’ which we cannot see! We are very dubious about this assessment as we are not experiencing any damp problems. What do you think?

    • Joe Malone

      Hi Julie, I keep being told that the damp proofing industry is changing and yet there’s not a week goes by where I don’t receive an email or blog comment like this. You cannot diagnose rising damp with a hand held electrical moisture meter and you should completely disregard any comments made by the CSRT surveyor as they have no evidential basis whatsoever. What I do also find interesting is the amount of remedial companies jumping on the cavity wall insulation bandwagon but you should also ignore that claim. It may be badly installed, more often than not, this means poorly filled, but unless there is evidence that it is transferring moisture to the inner leaf of masonry, then this suggestion should also be ignored. You will need to have the masonry tested for moisture at depth using calcium carbide to ascertain whether it is affected by wall base damp or penetrating damp. Regards. Joe Malone

  • Adrian Dawson

    You cannot ascertain if there is rising dampness affecting the wall by the use of a carbide meter either, as this only measures TOTAL moisture content, at the point tested, it will not tell you the moisture content to the other areas of the wall.

    I agree the use of a moisture meter is limited, but when undertaking a pre-purchase survey it is the house owner will not allow destructive testing to be undertaken,

    As we discussed at some length at our last meeting the damp proofing industry is and has changed, unfortunately it would appear you are unable to accept this and also the limitations which are imposed when undertaking a pre- purchase survey, when destructive testing cannot be undertaken.

  • Joe Malone

    Adrian, firstly. we didn’t have a meeting, you attended one of my CPD talks. The fact is that dry walls are dry. We’ve tested hundreds of walls with carbide that have a zero moisture content so clearly no capillary moisture content (CMC) or hygroscopic moisture content (HMC).

    You really want to put forward a theory that if a wall has a total moisture content of 10% at wall base which gradually reduces with height that this isn’t diagnostically significant because its been done with calcium carbide? We all know the theory, that you should subtract the HMC from the CMC, which will give you the total moisture content, but you conveniently omit to say that even if this process is followed then it can be followed with calcium carbide testing. Perhaps you want to put forward the theory that gravimetric testing is more reliable… arguably so, but what about moisture lost transporting to the lab, and what about the high cost of such testing when for arguments sake we may have a dozen samples for a particularly wet property?

    Gravimetric testing is not practicable or cost effective and the best tool any site practitioner has is calcium carbide testing; it is accepted by all the academic literature and accepted by the courts. You state that I don’t accept the damp proofing industry has changed, though I’m not sure why what I think would be of any concern to you, but yet are responding to a blog that gives two examples of how at least one damp proofer hasn’t changed. I’m unsure if you are supporting the diagnostic work detailed in this blog (the exclusive use of a hand held electrical moisture meter to diagnose using damp) in preference to calcium carbide, though you do seem to agree that its use is ‘limited’ but what position would you like homeowners to be in? Do you want to put forward the theory that moisture meters are the only practical option they have or that only gravimetric testing (oven drying) can diagnose rising damp? I do not accept your argument that homeowners won’t allow invasive testing and I think this is a spurious argument because we do it on an almost weekly basis and we do it for pre-purchase surveys. In fact home owners are generally extremely pleased because in the majority of cases it rules out significant wall base damp and facilitates the sale without the need to resort to installing expensive and unnecessary management solutions. I do think there is a critical point that you missed, which is that we operate in very different worlds Adrian, you are in the business of selling management solutions for damp and we are not. We get paid for a professional opinion that allows clients to cure rather than manage damp. So where we find dampness in properties (after calcium carbide testing) we move the investigation towards looking for the source of that damp and not towards installing a system to hide it. Almost always this leads us to finding significant subterranean leaks. I think Steve Hodgson made reference to a piece of research carried out that proves definitively that these management solutions work, and it may well be an excellent piece of work, but critically it would make no difference to our position because we hold a view that management solutions are almost never required.

    I have no problem with any damp proofer who installs a management solution so long as they have done credible diagnostic work to prove that wall base damp is present and so long as they explain to the client that they are buying a management solution and not a cure. We generally find that clients want a cure as opposed to a management solution, once the difference is explained to them, but if you have fully informed clients who are happy to buy into management solutions then it really isn’t something I’d criticise, as always it is purely about allowing clients to make informed decisions.

    • Adrian Dawson

      Hi Joe

      You are right, I did attend one of your CPD talks which was interesting, followed by a discussion after which is what I was referring to when I said meeting.

      I have not come across a vendor who is willing to have their walls drilled on a pre purchase inspection as both carbide and gravimetric testing results in damage to the décor and structure which requires repair, I have also not come across a court which will accept a carbide test over a gravimetric test, as the carbide test is inconclusive in relation to hygroscopic moisture.

      Your point about moisture being lost in transport for gravimetric testing is incorrect, as the sample is placed within a constant environment of 75%rh for 3-5 days as part of the test to acclimatise so the results are quotative to the sample at the time of testing, if taken correctly the sample would be transported in an air tight container anyway.

      I do agree carbide testing if undertaken correctly is a good indicator, the same as deep probe testing which you also mentioned in your CPC, which I used on a cavity wall insulation inspection last week, but they are both only a form of measurement.

      As I said when we had our discussion, I agree with you totally in finding and correcting the cause of the moisture, and this is how we survey, I recently put a post up on linked making reference to this.

      As I said during your CPD you appear to be out of date, especially relating to the systems which are installed today, the days of a cement render have long gone.

      The systems which are installed today, are independently tested by universities and are accepted by English heritage as they are more vapour permeable then lime, SPAB are working with us to as a way of going forward.

      The document Steven Hodgson referred to is a PHD study by Les Sellers, the link is below, this document is not referring to managing anything, it is a discussion document refencing both sides of the discussion and testing with data on if the systems work or not, which people have been asking for years, now it has finally arrived you can down load it from the link, it’s a good read.

      http://usir.salford.ac.uk/43721/

      Kind regards

      Adrian

      • Joe Malone

        Hi Adrian,

        Yes, we did have an informal discussion after the CPD session. I didn’t actually mention what Les Sellers PHD covered, just that I heard mentioned that it proved conclusively that management systems work. Thanks for the link and I will read it as soon as I get time.

        I didn’t state that moisture got lost in transport… I asked the question to get your view, because whilst hypothetically what you say is true, the reality is that moisture loss during transport is inevitable but as I said from my perspective it’s a mute point because gravimetric testing is not practicable for site investigation and calcium carbide does the job perfectly well at a cost that is palatable to the client. You state that I’m out of date with current systems and that cement render is a thing of the past but I can assure you it isn’t Adrian, we still see it regularly used. If I am out of date with current systems then thats fine because we never specify them and don’t recommend them. For those of you out there doing your best and trying to provide a good service to informed clients I wish you well Adrian, but as I said, we operate in very different worlds and our clients have little or no interest in buying into management solutions.

        Kind Regards.

        Joe

        • Joe Malone

          Only two days after the discussion relating to whether cement renders are a thing of the past, I received a specification to review from one of our clients in London. The specification relates to damp proofing works allegedly required in a large semi-detached built in 1827. The internal plaster was to be hacked off and replaced with a cement render and the following text was cut and pasted from the specification/quote… ‘Therefore plaster must be removed to a height of approximately 1.0m wherever practical, and re-plastered to a specification of SHARP SAND and CEMENT to the ratio 4:1. A waterproofer/salt retardant additive must be used in the render. Final skim in MULTI-FINISH.’

          • Phil Moran

            Hi Joe
            We have been given this quote and have verbally accepted unfortunately having just come across your site. From what I have read, Iam pretty sure that we have a drain problem. The kitchen waste drain runs from the back of the house under the garage to join the toilet waste drain and an external ( but within the garage) bathroom water drain. Dynorod have dug up the garage floor and replaced some pipe work in response to bad odours in the garage. This was a couple of years ago and they recently put a camera down the toilet and open drain but said there were no apparent leaks. However not sure if they included the kitchen drain! Might recontact them now I am better informed! Thanks for the site.

            Regards Phil

  • Phil Moran

    Sorry, further to my emai I did not attach damp quote

    A moisture reading was taken with an electronic moisture meter which recorded high readings to the areas highlighted on the enclosed sketch and as discussed on site. The plaster has perished in places to these indicated areas.
    We therefore recommend a damp proof course to be carried out. The plaster, in relation to the d.p.c., to be removed to a maximum of 1m and a minimum of 50cm, the walls tanked where necessary and finished with a renovating render.
    Should plastering be carried out by client/client’s own builder, then when re-plastering carlite browning or bonding must not be used. We recommend either renovating plaster, else a sand and cement render us- ing silver sand ensuring that an adequate water repellent is applied.
    Please note if either carlite browning or bonding is used on this property then our thirty-year guarantee will considered void.
    We do not recommend decorating to commence until the new plaster has been allowed to dry naturally, for approximately six weeks and then only a light coat of adhesive to be applied.

  • Phil Moran

    Joe, the whole point of my comment , besides supporting your assertions, was to ask why is our wall in three different places showing signs of severe damp and wallpaper damage if the d p c is ok. Surely even if the drains are saturating the foundations in the earth under the wooden floorboards the dpc should stop this?

  • Francesca Mooney

    Hi Jo, I’ve been enjoying reading your blog which is starting to help me understand my own house.
    I’ve had it 18 months. It’s an end of terrace typical 1900’s house.
    No sign of damp when we viewed it. The house had been empty for around a year. Once we got the keys and turned the stop Vicks on we found the water main had burst under the 70’s concrete floor in the kitchen extension and a river was running through the house under the timber floorboards and over the driveway at the front.
    We ran dehumidifiers and redecorated but ever since the kitchen walls have never quite dried out 100%.
    There is a tide mark at around 2m high with salts appearing on the formerly external and now internal kitchen wall.
    There is also an external wall where the paint flakes low to the skirting board which I assumed was due to the concrete still expelling moisture and it going up through the walls.
    However, I’ve had multiple people out who all tell me it’s rising damp and promptly tell me to inject a dpc and replaster.
    It’s been 12 months since the leak.
    Could it be that the old plaster never dried fully in that time and the salts keep attracting the moisture from the air?
    I’ve spent so much time and money with surveyors that I’m about to give up and agree to the damp proofing work just to be done with it, but it’s an old house and I want to live here long term and fix the problem.
    The last time a surveyor came out they used a thermal imaging camera which showed the wall that appears to be damp is as warm as everywhere else with no cold spots.
    We lifted the carpet and floorboards to the part of the house without concrete floors and it was sound.
    The vents through the house are clear and above ground.
    We’ve had heavy rain the past few days with the storms and I noticed a little water bubble about the size of a 5p peice on the external kitchen wall which on the outside the render looks clear with no cracks, but I’m assuming something must have made its way in.
    The patio on the outside is below floor level but could possibly be too high still, or maybe where the gas mater is fixed to the wall there is some ingress where the fixings are.
    Could our problems all stem from the mains leak from over a year ago?
    Thank you for reading

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