Damp Specialist - What qualifications should he have?

ahfh1

Hi,

I'm after a damp specialist to do a damp report. Anyone know what specialist qualifications he shoud hold to do a good job?

Cheers

ukmaggie45

We need one too on a house we hope to buy, we've been in touch with Peter Cox Ltd. They suggested we speak to vendor of the house to find if any damp proof work has been done before as if so there may be a guarantee in place. EAs are now trying to find this out for us. We suspect there hasn't been any work done before, and if that proves to be the case we'll go with Peter Cox - they did work on DD's home and she and SiL are happy with it.

Maggie

PasturesNew

http://forums.moneysavingexpert.com/showthread.html?t=287736

David_Aldred

Hi - sorry for such a late reply but I have only just joined the forum and seen this query. The qualifications to look for are CSRT (certified surveyor in remedial treatments) and CSSW (certified surveyor in structural waterproofing). However the question posed is far more complex than that.

Each year Chartered surveyors inspecting houses for their clients, upon finding high damp meter readings, some evidence of decay, wood boring insect attack, or suspecting cavity wall tie problems recommend their clients to have a specialist inspect the problem. Unfortunately the vast majority of people claiming to be a specialist are contractors selling these treatments for profit and any builder can call themselves a specialist. Most have no qualifications at all and as such have no professional indemnity insurance to write the reports that you are relying upon. Many of those inspecting are paid upon commision to find work for their employer, whether or not that work is justified.

Electrical damp meters cannot prove rising damp at all and anyone who claims their electrical damp meter showed rising dampness is misleading their client be that a surveyor or a contractor. Read their cleverly worded reports and you will see phrases such as indicative of rising dampness, of a pattern associated with rising dampness, appears to suggest rising dampness - all of which are phrases that are not confirming rising dampness at all.

The only way to prove rising dampness is by laboratory anlaysis of wall samples. An original dpc may crack with settlement but this would only produce small amounts of dampness up through such cracks and not full wall lengths as often seen. Statistically only 10% of dampness is rising damp, so the because it is so hard to prove and because it is so rare, take the common sense approach of resolving what is obvious before considering dpc failure. It is not surprising that failure of original damp proof courses is vastly over stated by those selling new dpc's and a whole industry built up around new damp proof courses, where contractors are taking nothing more than a best guess for profit.

It is not unusual to see three of four damp proof courses (dpc's) to a house yet dampness remains a problem. Why is this the case? Because there was nothing wrong with the original dpc. Upon recalling the contractor to look at why the house is still damp they deny the problem is anything to do with their dpc / rising damp and of course they are right because there was nothing wrong with the dpc the house was built with!

Although lucrative when contractors start out in the business (specialist treatments are never cheap) the amount of re-inspections starts to cost more than the amount of new work coming in and the contractor all too frequently eventually goes bust and may start up under a new name often leaving all those long term guarantees with their old firm as worthless.

The same applies with 'woodworm' treatments where the same house is sprayed several times with chemicals for inactive wood boring insect attack that some contractor simply seeing holes in house timbers takes as a guess for profit at being active / requiring insecticide sprays. Many such insecticide / fungicide chemicals have had to be withdrawn in the past because of long term cancer / health issues with these long lasting products.

Having worked in the industry for many years I know that when damp / timber / cavity wall tie firms are struggling and their staff inspecting aproperties are desperate for commision and under pressure from their boss to keep the lads in work how open to abuse the whole system is and this is not helped by surveyors steering their clients into the hands of specialist contractors and likewise some estate agents / mortgage advisors steering their clients into the hands of such contractors who have paid for these people to advertise or at least suggest their company either legitimately or illagitimately.

If you have ever tried claiming on a dpc / woodworm guarantee then you will know what a fight this can be.

All of this is why I would strongly advise anyone asked to obtain a damp / timber / cavity wall tie report, to take the following approach: First seek out a truly independent surveyor who is not a contractor, is fully qualified and who specialises in these subjects to inspect the problem and give unbiased advice to you that is covered by professional indemnity insurance.

The key and prime requirement in all of this, if you have any sense at all is that they should never be a contractor but that they are truly just a specialist surveyor who is totally independent and not linked to a contractor in any way shape or form. That inspection and report will be in depth and take several hours to prepare and should have drawings, photographs etc explaining what is found, conclusions and recommendations.

Such surveyors can be found within the Property Care Association website but be careful to make sure you look under the heading Freelance Surveyors and Consultants for one in your area. All the other memebers are contractors and whilst these PCA contractors should have qulaified surveyors we recommend you go for the unbiased advice first due to the above reasons. Remember that as in most cases there are good and bad surveyors and contractors and I do not want to paint everyone with the same brush as there are some very good contractors indeed out there who are struggling with the shall we say less scrupulous contractors.

That unbiased advice from an independent inspection is most often to suggest resolving such problems by simple basic house maintenance / traditional construction / managing condensation and thinking about how that house was originally designed to function and what perhaps has changed since that time.

Such a surveyor can give estimates of expected costs for you to go back to the house seller with and can provide a specification for works required that good competant qualified contractors can then be invited to tender for if work is required. Simply asking a contractor to look at the problem first is like asking a builder to build you an extension in whatever manner they feel like, or asking a double glazing salesman if you need new windows. I hope all of this helps - if you would like further advice / simply a chat over the phone please send me a private e-mail. Kindest regards to all, David Aldred independent dampness and timber surveyor

Richard_Webster

And sadly most of the companies go out of business after a few years leaving worthless guarantees that we have to send our time asking for!

Patr100

David, where do you get your figure of 10% actual rising damp whereas Jeff Howell says its an likely as the tooth fairy ie a myth ?

David_Aldred

Hi Patr100,
I include houses that have no damp proof courses at all. Staistically 70% condensation, 20% penetrating damp / leakage and 10% rising damp tends to be a rough approximation of dampness problems seen.

Building Research Advisory Service, Technical Information Leaflet TIL 47 August 1982:- "The diagnosis of rising damp needs careful and systematic thought because it can easily be confused with penetrating dampness and condensation. The Building Research Establishment (BRE) have suggested that only 10% of the dampness problems it investigates are attributable to rising damp.

BS6576 gives guidance to those looking at dampness problems to houses but their approach to it is clear - since rising damp is so difficult and costly to prove and since statistically it is by far the least common cause of dampness, resolve what is obvious first other than rising damp and monitor for drying down before considering whether such laboratory analysis to investigate the dpc is justified. BS6576 confirms electric damp meters cannot prove rising damp.

BS6576 para 4.1 before installing a chemical dpc it is essential to establish whether rising damp is present. BS6576 para 4.2.1.5 if positive evidence of rising damp is being obscured by other faults such as those described in 4.2.13. it is preferable that those faults should first be remedied and that an appropriate period of time shoudl be allowed to elapse before making further checks to ascertain the presence of rising damp.

Since public health legislation demanded provision of such damp proof courses well over a hundred years ago the majority of the british housing stock was built with a damp proof course be that slate or bitumen or other materials, although this is often difficult to see externally if paths are high / painting / render etc.

Rising damp is moisture rising up through the walls by capillarity and it can occur where there is no effective control to such an issue. The effect of moisture rise can be shown in a laboratory / classrom as moisture climbs up a very thin gauge tube when placed in a glass of water. The rate and height to which it will occur in a house however is cause for a great deal of debate and if occurring at all will depend upon several factors such as lack of an effective dpc, the pore size of the wall material, the thickness of the wall etc.

The BRE and many others have had a great deal of trouble trying to reproduce this effect in sample masonry sat in water and this has been due to many reasons such as the pore size of the mortar / masonry etc being variable and where not appropriate the effect will simply not happen. If there is one thing walls to houses in the UK are it is variable.

However and the point I was trying to make is the rate of misdiagnosis with a system open to abuse from those selling dpc's to the public who may not question such recommendations. Putting an electrical damp meter upon a wall surface will only highlight areas that should be further investigated and high readings do not prove failure of a dpc.

People ask what else could cause such high readings to damp meters at the base of walls and the answers are many - examples to illustrate the point are debris within the base of cavities to external walls which will allow moisture to rise up through it and give all the effects of rising damp even though the dpc in the wall remains effective, such debris will also allow penetrating damp across the base of the wall and being semi solid with such debris it will be a cold spot prone to condensation both on the wall surface and within the depth of the wall itself.

If the oversite beneath timber ground floors is damp / wet then this will be absorbed by brickwork above the level of the dpc (which should be below floor joists and within that same sub floor void) just as much as it will be absorbed by brickwork below the dpc since the materials want to be in balance with the humidity of the sub floor void, such moisture will also be absorbed by low level plaster and skirting / base of stairs / architraves / door frames / floors directly above whether or not the dpc is effective.

To solid ground floors, the floor will tend to move seperately to the walls and a gap develops here between the wall and the floor where dampness can emerge whether or not the dpc in the wall itself is effective, especially when no floor damp proof mebrane is sealed into the wall dpc to give one complete barrier to ground moisture.

Cavity wall insulation can compound dampness to external walls.

If condensation / penetrating dampness trickle down the cavity wall and cannot readily evaporate / drain externally then it will migrate internally causing low level dampness. There can be materials within the plaster / wall which will make the plaster hygroscopic if it fails to hold such contaminates back such that it will absorb moisture from the air and this can make the wall very damp indeed.

Sulphates from black ash mortars and soot migrating into plaster, chlorides from coastal exposure, historic flooding, penetrating damp from high ground may bridge the dpc such that moisture can bypass the dpc and also if paths slope towards the property directing rainwater from paths etc into walls / foundations / sub floor voids this can cause low level dampness.

If a property is low lying compared to local water tables then moisture may drive up through walls under hydrostatic pressure which is not the same thing at all as moisture rising by capillarity(rising damp) There may be foil backed linings to wallpaper that will give false high readings to electrical meters.

The list obviously goes on. The approach therefore is to be open minded and look for what is apparent and proven ruling each issue out before rushing to blame the poor dpc the house was built with. A slate or bitumen dpc may crack as the house settles with age but how much moisture would in all honesty rise up through such cracks - would it make full wall lengths damp - if the answer is no then use a bit of common sense and look for moisture sources / how such high readings could be caused before rushing to spend thousands of pounds on a new dpc because if that new dpc is misdiagnosed and the replacement plaster from such work begins to fail / dampness returns, the contractor is going to deny it is anything to do with them / the dpc.

Kindest regards David Aldred independent damp and timber surveyor

Patr100

David Aldred,
Firstly it's quite hard to read a block of text copied and pasted without any paragraphs.
Having read it it doesn't really address the issue.

The Building Research Advisory Service, you quote say 10% rising damp, Jeff Howell categorically says 0%.
Either rising damp (as opposed to the causes of damp) exists as a phenomena or it doesn't.

David_Aldred

Hi Patr,
The text was written by hand not copied and pasted, so sorry if it is hard to read I should have banged more paragraphs in but seeing as they are comments given for free in good faith that I have nipped in amongst my other work that pays the bills I cannot spend too long trying to make them look pretty - note to self must try harder and have gone back and put some paragraphs in so hope this helps.

The BRE Digests, BSI and PCA documents are some of the core ones I present as evidence in my court work as an expert witness in these subjects of dampness, timber decay, wood boring insect attack and cavity wall tie problems, not comments made by Jeff Howell unless they are undisputed fact. I haven't lost a case yet so I must be doing something right.

If you would like to read more on this complex subject of dampness one of the best books out there is Dampness In Buildings by James Douglas & J Stewart Stirling or please give me a ring to have a friendly chat over the phone and I will do my level best to help anyone including yourself.

Kindest regards, David Aldred independent dampness and timber surveyor

Leif

Patr100 wrote: »

David Aldred,
Firstly it's quite hard to read a block of text copied and pasted without any paragraphs.
Having read it it doesn't really address the issue.

The Building Research Advisory Service, you quote say 10% rising damp, Jeff Howell categorically says 0%.
Either rising damp (as opposed to the causes of damp) exists as a phenomena or it doesn't.

I know this is an old thread but I feel it is worth adding a comment. I would be wary about taking what Jeff Howell says as truth. Here is a review of his book:

http://www.buildingpreservation.com/~building/images/stories/pdf/jhrev.pdf

I recommend you read the review, and it is a damning critique of the book, showing that it has significant factual errors. I am not qualified to comment on the detailed content, but the very fact that Howell makes so many errors is worrying. And note that the author has an impressive set of credentials. From what I can see Howell's claim that rising damp is a myth is false, although as many say, many if not most supposed instances of rising damp are in fact penetrating damp and/or condensation.

I for one appreciate the informative posts by David Aldred.

Mlucas

I run my own medium sized plastering business and am thinking about expanding into damp remediation etc. I want this to be a viable and reputable part of our services so would be very grateful if someone can advise any training courses or qualifications to supply a fair and competent service.

Many thanks