A RESPONSE TO THE REPLY FROM ARCHIMETRICS LTD
CONCERNING THEIR REPORT

My response to each section of the reply, where appropriate, is given in bold italics: The reply from Archimetrics is given in full.

“We thank Graham Coleman for taking the time to feedback on this work and appreciate that all comment is welcomed.

In summary we understand that Graham has highlighted a data handling error and he feels the data collected for all 3 properties simply shows that the walls rapidly find their equilibrium with external conditions regardless of wall material and thickness, retrofit measures taken, orientation and other variables which may have an effect on performance.”

There is more than “a data handling error” eg, recording data which includes absolute humidities which cannot occur in the UK, recording a relative humidity of 0% which cannot occur and concern over the performance of the data loggers and interpretation of the data.

“In response we would like to offer the following:

The data handling error concerns external conditions data. Data collection can of course be a difficult undertaking in the real world and when allowing for uncontrolled events. Our external data has indeed suffered outages for variety of reasons which include one home owner turning the mains off every night until the morning without prior notification, damage to our external wireless logger from building maintenance again without notification, sensor failure due to in-service conditions etc. These data holes are both declared and visible.”

I have over 45 years of data collection and analyses in the real world, and fully appreciate the comments about data losses, etc. It is important to show how the data was handled where it is missing/intermittent-this is not the case in the report, and as a consequence the results of which can and will lead to flawed outcomes.

In the report page 5 it states, “Where data is missing from an analysis values are shown as unchanging or as a gap and where this impinges on the written discussion the absence is noted within the text.”. There are only 2 instances where a “gap” has obviously been left – correctly – for absence of data (tables 3 and 9). In tables 5 and 11 these same gaps have been filled with 0.00 figures, that is data-and this has been included in the average. If there have been missing data then it certainly is not clear in what data series these occur, and how they were actually handled. According to the report the absence of data can be made up by, “-analysis values are shown as unchanging–” – in other words add false data. The data holes are not properly declared and only in 2 tables are they clearly visible.

“We acknowledge that these data holes have been incorrectly handled by the code we have written to analyse the data, this simple error is clear to see and easy to correct. This has obviously slipped through the review process.”

This statement is of concern and may have serious consequences for the project as a whole.

If the “code” you have written has mishandled data holes (and thus probably some data itself, eg, obtaining some absurdly low absolute humidity figures) it is seriously flawed. If the “code” written has mishandled data for the latest report figures to give erroneous results then a serious question must be asked, has the same mishandling of data via faulty “code” occurred from 2011 to the present?

The above also states that, “-this simple error is clear to see and easy to correct. This has obviously slipped through the review process” If the “simple error” is now that “clear to see” then why wasn’t it “clear to see” at the time of collection, data handling and during the review? This now leads to the question of how many simple “clear to see” data errors have been missed over previous years. If such “clear to see” simple errors are being missed then this may question the experience and expertise of the researchers and reviewers. It also brings up the question with reference to ‘not quite so clear to see data errors’. As for, “–easy to correct.”, this is not going to be the case. If there are such data errors then it is going to be more than a simple adjustment since the data sets will need to be reviewed as well, of course, as the “code” that has led to the errors- present and probable past.

“The purpose of this work comes about from the widely accepted concerns that insulating buildings, especially traditional buildings can have unintended consequences. This long-term observation of 3 buildings is intended to shed a little more light on this area of concern with the view that it is better to look than assume.”

Notwithstanding the likely data errors, the current published data from past years to present does not appear to identify anything except internal/external atmospheric changes. There was only 2-4 weeks data collection in February/March 2011 prior to insulation. Subsequent to that there appears to have been effectively nearly 6 full years data collection for each property, certainly consistently from 2013 to present. The data during this period does not reflect any apparent change to the walls.

“We do not hold the view that all walls insulated or not, quickly find equilibrium with the external environment regardless.”

The report’s own data shows that walls find equilibrium moderately rapidly following changes in internal/external atmospherics.

“We do hold the view that insulating buildings may have negative impacts on some building fabric and occupants and that we should endeavour to understand the implications as best we can so as to improve the potential outcomes of improving the energy efficiency of our building stock.”

Unfortunately the monitoring data as reported does not throw any light on this; the data shows that there has been no effective change since at least 2013. There is no data over the years of monitoring that records any “impact to the occupants”.

“We do hold the view that this work, along with any other study, has its flaws and that there is always scope for improvement-we are constantly evaluating, developing and improving through experience. It is not uncommon that the act of undertaking to answer a question often reveals further questions, acknowledgement of this fact forms an important part of our ethos.”

Any study will have ‘limitations” but should not have “flaws”, in other words wrong information-there is a significant difference between limitations and flaws. If a study is shown to have flaws then its value will be diminished: any flaws should have been identified prior to publication and resolved, and if subsequently found, the paper should be withdrawn for correction and re-evaluation.

“As part of a constructive review process, we would welcome a face to face meeting with Graham to discuss his views, in the hope that this might further understanding of this important field.”

I would be most pleased to meet to discuss

G.R.Coleman. B.Sc.(Hons).,C.Biol.,M.R.S.B.,A.I.M.M.M..

SOME OBSERVATIONS OF THE SPAB RESEARCH REPORT 2. THE SPAB BUILDING PERFORMANCE SURVEY 2016 INTERIM REPORT: 2017

Introduction:

The report ‘The SPAB Building Performance Survey 2016 Interim Report: 2017’ was first made available last year. Having first taken a quick glance at its contents it became apparently clear there were obvious discrepancies in the included tables relating to relative humidity (RH) and absolute humidity (AH) for the 3 properties under investigation.

A more in-depth inspection of the data in the tables has revealed errors and flaws which may reflect on the recorded information and interpretation of results.

The data recorded in the report are given as ‘averages’. It is therefore very important to appreciate that an average is:

“Number that is obtained by adding two or more amounts and dividing the total by the number of amounts”

Thus the average of the sum of 1 to 5 is 3: the spread is 1 and to 5. It is important to note that there is a spread around the average. Statistically this spread is important in that they will distinguish between natural variations and real differences

Be aware that there will be natural variations in data; thus it is imperative that the data shows a significant difference to identify any real change

Table 2:

Given there would distinctly be a spread around the above figures then there is no significant differnce between 2012 – 2016 for each sensor. Also note RH is temperature dependent thus it can simply reflect a change in temperature and nothing else

S1: Mean: 65.5% Min. 64% Max. 66%
S2: Mean: 71.3% Min. 71% Max. 72%
S3: Mean: 77.2% Min. 75% Max. 80%
S4: Mean: 81.8% Min. 79% Max. 84%

Note the largest spread is in those sensors towards the outer part of the wall, ie, closest to the external variable atmospherics.

Table 3:

Note 13 potential data sets; there are 4 omissions for the external data (no data – left blank). To obtain the average the 4 omissions are ignored and the total remaining divided – correctly – by 9

Table 5:

Note: 13 potential data sets for the external data; there are 4 recorded as 0.00. It is impossible to get an AH of 0.00 in normal earth atmosphere. Looking at Table 3 these 0.00’s are clearly ‘absence of data’ yet they have been included in the total of 13 to get the average. This makes a nonsense of the average and distinctly reflects poor data handling.

Table 4:

Given there would distinctly be a spread around the above figures then there is no significant difference between 2013 – 2016 for each sensor.

S1: Mean: 9.80 Min. 9.56 Max. 9.94
S2: Mean: 9.74 Min. 9.42 Max. 9.92
S3: Mean: 10.25 Min. 9.69 Max. 10.71
S4: Mean: 10.01 Min. 9.65 Max. 10.58

Note again the largest spread is in those sensors towards the outer part of the wall,ie, closest to the external variable atmospherics.

Table 5 (mis-numbered in report):

Average pre-insulation data collected over only 4 weeks in January/February 2011 (winter). This is being compared with an annual average (over approximately 52 weeks) 2012 to 2016. This is extremely bias scientific analyses – it therefore becomes irrelevant.

2012 – 2016:

S1: Mean: 6.48 Min. 6.33 Max. 6.85
S2: Mean: 5.09 Min. 5.00 Max. 5.16
S3: Mean: 4.04 Min. 3.08 Max. 4.24
S4: Mean: 4.79 Min. 4.62 Max. 5.11

Note again the largest spread is in those sensors towards the outer part of the wall,ie, closest to the external variable atmospherics.

Table 6:

Note: 13 potential data sets for the external data; there are 4 recorded as 0.00. Looking at Table 3 these 0.00’s are ‘absence of data’ yet they have again been included in the total of 13 to get the average. This again makes a nonsense of the average and distinctly reflects poor data handling.

Figure 5:

The report records an average internal RH of 69.33%. This figure suggests that there is likely to be an internal atmospheric moisture problem – if the recorded data is correct. This very likely
to influence the recorded data through the wall

Table 8:

Given there would distinctly be a spread around the above figures then there is no significant difference between 2012 – 2016 for each sensor. Also note RH is temperature dependent thus it can simply reflect a change in temperature and nothing else

S1: Mean: 64.8% Min. 63% Max. 68%
S2: Mean: 88.0% Min. 85% Max. 90%
S3: Mean: 93.3% Min. 90% Max. 96%
S4: Mean: 96.8% Min. 96% Max. 98%

Table 9:

Note 12 potential data sets; there are 2 omissions for the external data (no data – left blank). To obtain the average the 2 omissions are ignored and the total remaining divided – correctly – by 10 for the average.

Table 10:

Given there would distinctly be a spread around the above figures then there is no significant difference between 2013 – 2016 for each sensor.

S1: Mean: 9.34 Min. 9.15 Max. 9.64
S2: Mean: 10.59 Min. 10.04 Max. 11.13
S3: Mean: 10.91 Min. 10.24 Max. 11.49
S4: Mean: 10.68 Min. 10.17 Max. 11.04

Table 11:

Note: 12 potential data sets for the external data; there are 2 recorded as 0.00. It is impossible to get an AH of 0.00 in normal earth atmophere. Looking at Table 9 these 0.00’s are ‘absence of data’ yet they have been included in the total of 12 to get the average. This makes a nonsense of the average and distinctly reflects poor data handling.

Also from the recorded data:

Month RH AH g/m3 Temperature ºC
September 88.28 0.53 ?!!
October 89.01 2.52 ?!!
November 90.19 3.06 ?!!

To obtain AH averages of this order given the RHs’, the average temperatures would have to be so absurdly low as to be completely unbelievable.

Table 12:

The average pre-insulation data was obtained over 2 weeks only in March (towards end of winter) 2011 then compared to the FULL ANNUAL data (around 52 weeks) AVERAGE 2012-2016. This can only be considered an unrealistic comparison (eg, ‘apples to pears’) and is meaningless.

Table 15:

Given there would distinctly be a spread around the above figures then there is no significant difference between 2013 – 2016 for each sensor. Also note RH is temperature dependent thus it can simply reflect a change in temperature and nothing else

S1: Mean: 77.7% Min. 77% Max. 78%
S2: Mean: 90.3% Min. 89% Max. 91%
S3: Mean: 96.7% Min. 95% Max. 99%

Note the largest spread is in those sensors towards the outer part of the wall,ie, closest to the external variable external atmospherics.

The recorded average RHs for sensor 4 of 110% and 112% are not possible and are well outside the reported operating parameters of +-3%: this strongly suggests faulty loggers.

Figure 34:

The minimum external RH data is recorded as 0.00%. This is an absurd figure and indicates a total absence of water vapour in the atmosphere – nonsense.

Table 16:

Logger S4 records consistently an RH average of 111-112%. RHs’ of this order do not exist: they are likely to indicate a faulty logger. The data is well outside the reported operating parameter of +-3%.

Table 17:

Given there would distinctly be a spread around the above figures then there is no significant differnce between 2013 – 2016 for each sensor.

S1: Mean: 11.98 Min. 11.56 Max. 12.24
S2: Mean: 12.97 Min. 12.73 Max. 13.32
S3: Mean: 12.76 Min. 12.60 Max. 12.91
S4: Mean: 12.29 Min. 11.75 Max. 13.05

Note the largest spread is in those sensors towards the outer part of the wall,ie, closest to the external variable external atmospherics.

Table 18:

The external average external AH for April is given as 2.33

So for April: RH=93.99% AH = 2.33 g/m3 Temperature = ?!!

To obtain an AH average of 2.33 given the RH, the average temperature would have to be so ludicrously low as to be completely unbelievable for April, thus an absurd figure

Table 19:

.

The average pre-insulation data was obtained over around 2 weeks only in February/March (winter) 2011 then compared to the FULL ANNUAL data (around 52 weeks) AVERAGE from 2012 (7 month average) to 2016. This can only be considered an unrealistic comparison (eg, ‘apples to pears’) and is meaningless.

COMMENT:

The minor average variations in the annual data are the result of the natural variation of internal and external atmospherics. There is no evidence provided, certainly from 2013, to show the insulation has afforded a change.

There is insufficient pre-insulation data to make any proper evaluation of subsequent conditions.

Walls are effectively a constant and will relatively rapidly come into equilibrium with internal/external environments should any changes been made to those walls such as insulation. Such changes do not take years; this is clearly shown in the recorded data

There is no evidence provided that the 2013-2016 data is not simply reflecting the internal/external atmospherics, ie, there has been no real change since 2013 and possibly the year before. In order to do so it would require appropriate statistical analyses (a preliminary statistical evaluation of the data provided does not show any effective change over the years) .

The basic data handling errors and calculations are readily evident and are so fundamentally basic and obvious it is surprising that they were missed in the reported review of the report let alone published. If such erroneous data can readily have escaped review then one must seriously question all previous data recorded from 2011 onwards.
The fact that these fundamental errors are obvious have escaped both the researchers and the reported review does seriously question the experience of both the researchers and reviewers in investigations of this nature, eg, Averages which include ‘no data’, RH of 0%, absurdly low Absolute humidities at levels which are not obtainable as average in the UK.; the report and ‘science’ distinctly shows a lack of scientific rigour.

This report has been published and in the public domain. Therefore, given the errors identified, some at an absurd level and readily evident, then it might be prudent to ‘pull’ the report from further exposure; given the above, this same consideration is likely be relevant to previous reports/data. Based on the evidence in the report there seems to be no justification in continuing to monitor the 3 properties when there is no evidence to show there have been any real changes, certainly since 2013. Therefore given the quality of the report and data such further funding cannot be justified.

G.R.Coleman B.Sc(Hons).,M.R.S.B.,C.Biol.,A.I.M.M.M..

Note from the blog owner:

Following Graham Coleman’s review of the above; Archimetrics Limited (the authors of the report), replied and asked for a pubic response. This can be read on this site here

Viscous fingering and its misinterpretation

Introduction.

Chemical DPC’s have been used and misused for decades. There are very many reasons for this. However, now it’s come to building professionals raising the question; do chemical DPC’s work and is there such a thing as rising damp? This post doesn’t answer these questions; to ask them reveals a level of  ignorance that I won’t pander to. However, this post addresses the real issue of how recent austerity, combined with years of complacency, has allows a situation to arise where really clever people start acting like panicking schoolchildren and all faint together.  Read on and I will explain the underlying flaws in the current rush to abandon DPC work and why viscous fingering is taking center stage (even though it doesn’t matter)

Rising damp is a myth – rising damp is as rare as rocking horse sh*t – Rising damp is incredibly rare – Rising damp just doesn’t happen – Chemical DPC’s are a waste of time due to viscous fingering

Five daft statements by four Chartered Surveyors and an Architect; what’s going on?

Gravimetric analysis of masonry samples with salts analysis to follow

The reality of rising damp has been documented for very many decades, with British standards institute, Building Research Establishment, university studies and many more validating not only the science of it but the accepted methods of resolving the problem. So why would building professionals make such statements? Is it because they have evidence to back this stuff up? Is it just opinion or, cynical efforts to gain notoriety (and therefore in this internet dominated world – valuable influence and money).

Who knows, you’d have to ask them in private. I doubt that the explanations would be backed up by any meaningful facts. The last ‘damp’ report I read from one of these chaps was 20 pages long and most of it was a self-aggrandising CV, followed by statements and solutions which didn’t logically follow the flawed findings made in the report – and this guy is a chartered surveyor, scientist and engineer! So again I ask; what’s going on?

Bear with me and I’ll tell you the truth (oops, I sound like that self-aggrandising consultant now… )

Some navel gazing is required to get an idea of why this has happened:

For decades damp has been dominated by the view that if the base of a wall is damp the answer is to inject chemicals into it and render it with rock hard sand/cement. This is daft of course; it can have its merits but there are some serious problems:

1. The base of a wall can be damp for many reasons other than rising damp
2. Not all walls are suitable for a chemical DPC’s or for that matter hard sand cement render
3. Diagnosis is often left to installers who may be commercially inclined to specify DPC work rather than diagnose related problems
4. Inappropriate DPC work allows latent problems to go untreated so clearly the DPC appears not to have worked.
5. Those installing DPC systems (including the plastering) have wildly varying skill levels and diligence

So there are very many homes with DPC systems in, which are inexplicably still damp (and many that are dry but these are apparently invisible). The result of all this is a natural and building cynicism about rising damp and its treatment. Let’s face it, if treated walls are still damp then chemical DPC’s are a waste of time aren’t they? Well from the above list we can see how this view could take hold in a layperson or consumer. But what about a professional surveyor’s or engineer’s view being so clouded? They are graduate professionals who should take a detailed and holistic view.

There’s some microscopic viscous fingering going on here – hence the brown ring (concentrate sulphuric acid on to dilute acid mixing with differing viscosity. Brown ring test

It’s clear that many so called failures related to DPC work are due either miss-diagnosis (whether intended or not), or defective workmanship. What about viscous fingering?

Viscous fingering.

This is really a term first coined (in our industry anyway) back in the 1970’s as the DPC industry began to realise that high pressure injection of chemical DPC’s worked better in some walls than others. Research found that as the fluid was pushed through the masonry (often at 150psi or higher), the fluid would find the easiest route. Fluid following behind the initial front would merely follow the preceding chemical, in effect leaving areas free of treatment. The problem was considered serious back then because solvent based chemicals were the most common type used in chemical DPC’s. Clearly the wetter the wall, the more resistant to solvent it is. Differing viscosity also influences how fluids mix. Thus the pressurised solvent could spread quickly into the ‘dryer’ sections. The route was established so lots more fluid was deposited in the least ‘needy’ sections. It was thought that the effectiveness of chemical DPC’s back then was variable, partially due to this (as you’ll read later – it’s red herring, there are other huge negative influences on DPC’s working as intended). It also begs the question; if there are areas which are dry and others wet – why would the dry areas matter, as they are clearly not ‘wicking’ water from the ground anyway? – it’s the damp areas we want to treat)

Viscous fingering is massively influenced by moisture content; pore size in the substrate and especially by the viscosity of the injected material (to get scientific look here https://web.njit.edu/~kondic/capstone/2015/homsy_annual_review_87.pdf ). The subject is huge and still poorly understood.

Experienced contractors would often say that “Some walls just don’t respond well to injection” and those of us old enough to remember those times can relate to that statement.

Beginning to resolve viscous fingering

The initial solution was to reduce pressure and switch to water based DPC systems. In the late eighties and by the nineties Low pressure siliconate became the norm. This was accompanied by a switch to injection into the bed-joint, rather than the masonry units. Bed-joints offer a more consistent capillary pathway than independent masonry units. The combined effects of reducing solvents and drilling bed-joints had a positive effect. There appeared to be a small increase in performance after these changes. Water is not initially repelled by damp in a wall so less pressure is needed. In addition, sections of wall which for whatever reason have ‘wicked-up’ ground water, are more inclined to accept water in the first place. This applies even if that water contains siliconate. Less viscous fingering was the result. Lots had been learned from so called ‘transfusion’ system such as that employed by Peter Cox for years. These were gravity fed systems which used water based formulation and no pressure, other than a little gravity (gravity being free and always available).

Viscous fingering tackled at last

In the nineties Safeguard Europe brought DryZone DPC cream to the market. Here was a system which required no pressure and the wall in effect ‘wicked’ the material into the bed joints. Other formulators followed and the injection cream method was very quickly established. However, Viscous fingering is back in fashion – a term now banded about as the new mantra. I was sat chatting to some of Yorkshire’s local authority housing officers the other day. As talk turned to chemical DPC installation one spoke up “But do they work Bryan?” he said. I replied “Only if the wall is suitable, has rising damp and if the system’s installed properly”. He smiled at me and, with a bit of a triumphant flourish said “What about viscous fingering, eh?”.

All of his colleagues fell silent and turned to hear my answer. I laughed and explained how that was old hat. They were surprised that I even knew what the term meant. Why?

It happens that one of the five professionals I mentioned had visited this authority earlier in the year. His ‘lessons’ included the gem that “Chemical DPC’s don’t work due to viscous fingering”. He was paid a lot of money to teach this flawed view. Apparently most of the talk he gave was about him, rather than rising damp. However, it still left the officers I spoke to confused and ill-informed about where chemical DPC’s fit into building pathology and home maintenance.

I say flawed view for a very important reason; I like keeping things simple. In surveying things are usually simple. A broken gutter leaks and causes damp – a broken extract fan in a bathroom causes mould – a bridged damp course causes rising damp.

The viscous egg white and less viscous rapeseed oil interact in the pan. Note the edge of the egg where it was fingering into the oil before heat hardened the egg and stopped the fun. Of course, by the logic of some surveyors this now means that frying eggs is unreliable (the egg was delicious though)

But something must be wrong if there are so many homes with chemical DPOC’s installed again and again?

This is the Elephant in the room; the reason many DPC’s haven’t worked is obvious and nothing whatever to do with scientific bamboozle-speak. It’s human behavior every time. Either the DPC wasn’t necessary in the first place (surveyor and officer fault) or, it wasn’t installed correctly (the technician and employer’s fault), or ALL of these things. These are the most common causes of continuing damp – it’s so obvious that only a very highly qualified specialist pathology scientist can’t see it. Playing around the edges with claptrap about viscous fingering, whilst misusing speedy moisture meters will not improve the situation. A common sense approach would be to concentrate on the reasons I have given for these failures. better  training, supervision and accountability are what are needed.

Rising damp in winter reveals the effects of hygroscopic salts above the visible efflorescent salt band

It’s not all about technicalities – it’s about money

This post cannot cover this entire subject; it’s multi-faceted and complex. There are technical issues and strong financial and social issues driving this change. Local authorities have been poorly served by their own officers, consultants and damp proofing specialists for years. Now, with decreased funds and rising tenant demands they have to save money. This is the one thing driving them to eagerly take on flawed advice from these guys. They must bring the cost of damp related issues down quickly – I understand and respect that.

Have social housing providers really been ripped off by damp specialists and their own approved contractors?

Well, as a damp specialist I don’t carry out much work for many of the local authorities in the Yorkshire area (one or two maybe). The reason is that almost all of the work is done via complex frameworks with big builder/facilities firms or national damp proofing specialists – everyone knows them. These chaps send out tender documents full of questions like; how much per linier meter of DPC injection? – How much for plaster per square meter? How much for skirting boards? How much for a thirty year guarantee?

As a specialist I have never bothered replying to these. They ask the wrong questions. It follows that all the authority and the facilities provider want is a price for a job. The fact that each house must be treated on its own merits is never in there. No questions about how a damp survey is carried out, what equipment is used or, how qualified the surveyor is or anything else like that.

It’s absolutely no surprise that as time passed councils have spent more and more installing DPC’s that were not needed. There was never any incentive for the specialist to do anything but be cheap. And of course, because the rates are low, volume must be driven up. The main contractors are incentivised to make money not save it.  The council officers are not incentivised; they are not trained correctly so they rubber stamp the damp specialist’s report. The tender system was never fit for purpose.

Dr Hindlefokker – quack rising damp specialist (sworn enemy of DryRot)

The end result is that the local authorities promoted and helped establish this broken system. Their reaction now is to replace the system without consultation or any meaningful outreach to try to fix it. Thus they are willing participants in outsourcing to another system. A system based mainly on flawed technical knowledge and a similar financial model, which is the inverse of the one they had before. The juxtaposition is that where DPC’s were always the solution before (wrongly), now DPC’s are never the solution (wrongly).

This is what happens when anecdotal evidence supports consumers underlying financial needs. It’s like the vendor of a house when it’s surveyed for a buyer and found defective. Vendors always believe the guy who tells them there is nothing wrong; telling the client what he wants to hear is the first staple of all good salesmen and of no interest to a professional. Has there been ‘ripping off’? Oh yes – it was built-in and inevitable from the start.

How to fix the situation

Proactive specialists and social housing providers are getting very proficient where it comes to damp diagnosis and the handling of tenant complaints. I myself consult for some of them, as do several well qualified and expert PCA members. Training officers and helping with surveys where things get complex is within the remit of any well qualified and experienced specialist. Effective training in damp diagnosis is readily available from the PCA. Their courses are superb and contain FACTS rather than half-baked sound bites.  In fact the Property Care Association have done wonders over the last ten years in setting higher standards and educating members and many others in the factual and significant things which should be taken into account where damp is concerned.

For anyone with a keen interest in damp diagnosis I would recommend you attend a PCA course at an early stage.

Yours with egg on my face

Dry Rot

I was in South Shields today as part of a Property Care Association team of examiners. The PCA group included Mike Bromley and David Hockey.

Our venue was South Tyneside Homes in South Shields, where there were ten staff sitting the timber infestations module of the Certificates Surveyor in timber and damp in buildings examination (CSTDB).

PCA examiners and our host (l-r, David, Bryan, Mike and Craig)

The CSTDB examination

CSTDB is a three-module examination, including this timber based session, as well as a dampness in building and health and safety module. The timber module is a daunting one, including extensive sections on timber physiology; surveying; entomology and mycology. Students have to know their hardwoods from softwood, woodworm for bark borer and wet rots from dry rot. In addition, they face a two-man grilling which is the famous oral (David and I this time).

That’s not all though – students are presented with a dozen timber samples, infested with a wide range of ‘nasties’ including different insects and fungi. These timbers need to be identified correctly.

The CSTDS – oral exam

Orals are designed to test candidate’s real-world knowledge, by presenting them with case studies and scenarios to see how they cope. This is my favourite bit because in our industry, practical and academic skill go hand in hand, so a written examination on its own, just wouldn’t do.

Chatting about infestations, sites and treatment options can open-up a person who may feel stifled in a written environment. Conversely, a gifted writer and academic who thrives in exams may stumble when faced with evolving arguments face-to-face.

This broad examination approach is part of the reason CSRT (the forerunner of CSTDB), has come to be recognised as the ‘must have’ qualification for timber and damp specialist surveyors. PCA go to great lengths to maintain rigorous standards. This ensures that those who work hard enough to obtain CSTDB, can be proud of their achievements and be sure their work is recognised across the industry.

Examiners don’t know everything!  South Tyneside Homes manager Craig, offered me something called a ‘Saveloy Dip’.  I was dubious, but being from Yorkshire I wasn’t going to say no to a free ‘sandwich’.

Mike Bromley isn’t sure about the Saveloy Dip… Bryan has other ideas….

Craig presented me with what can only be described as a dead man’s hand in a sandwich – the sausages (The ‘Saveloys’ reminiscent of fingers – the dip, a Pease pudding with a pus-like colour and texture) …. I twas delicious!

I learned lots today:

1. South Shields is the culinary capital of England
2. Tyneside Homes is populated by dedicated, friendly and professional people who deserve to prosper and
3. These guys know their rots!

Thank you to the team at PCA for organising the day and especially to all those in South Shields who worked so hard and took the exams with us today – well done. You all made David, Mike and I’s trip a real pleasure.

It’s not over yet, with damp modules to come. I’m sure that there will be success and disappointment by the end of the process. For those who pass – welcome to a growing club of specialists whose knowledge has been validated by examination. If the news is lees good – don’t despair, exams and modules can be re-taken, knowledge gaps filled and lessons learned. Don’t give up.

For the tastiest Saveloy dip – get the one I sampled from Dicksons.

Best wishes

Dry Rot.

Our day to day activities place stress on us to perform on lots of levels:

• Keeping the work flowing
• Make profit
• Cooperate with clients, contractors…. each other
• Avoid lost time and money
• Maintain our values

every Friday we meet up and talk about health and safety

These things are the bread and butter of any business. Get them right and the business will thrive; but at what cost to health, safety and well-being?

Here’s a story from this week’s projects, illustrating how the natural willingness to help and ‘get on with work’ can be a real threat and potential danger to our team and others. Don’t worry, there’s a happy ending. In fact the episode demonstrates how a positive health and safety culture can take root in a business and improve health and safety outcomes at crucial moments.

Ryan and Adam were tasked with some structural repairs, installing some remedial wall ties through a commercial building façade in Leeds. As specialist sub-contractors, employed to do this work via a cherry picker (MEWP), we planned and organised the work with safety in mind. The work was 5M above ground level.

Things changed at short notice.

On arrival Ryan was told that the work had changed and now the main contractor simply wanted parts of the masonry taken down. The nature of the change meant that the MEWP couldn’t be used and a working platform was needed.

The client was a shop-fitting firm on a very tight program. Keen to help the client, I attended site immediately, a new risk assessment was drawn up on site and a tower scaffold brought into play. However, the presence of steel work meant that only a slim single man platform would fit alongside the masonry.

Time was passing and it was gone lunchtime when Ryan and Adam managed to obtain the access equipment and erect it. When Ryan was stood at eye level with the masonry he had a good view and could really see what the work would involve. The stones were much thicker than they looked from ground level and would need at least two men to safely remove them. He called me on the phone and I said “Oh no, isn’t there some way we can chip them around the edges and cut them into manageable sections?”

Ryan paused and then quietly said “No Bryan, if they come loose it could be dangerous and on my own I couldn’t stop a bit falling out”.

Deep rooted safety.

Of course what was needed was a pause and a complete reassessment of the situation. I told Ryan to stop work and tell the site manager that in order to carry out the work, a tube and fit scaffold, suitable for two workmen alongside the masonry was required.

The client was not pleased and made this obvious to me. He wanted the work doing now and was very demanding about it. I refused and recommended a structural engineer and the access mentioned earlier.

So on that day, on the face of it we achieved nothing; no production; a client unhappy with a delay and Ryan, feeling that he had let the firm down. He told one of his colleagues that he hoped I wasn’t upset because he couldn’t get the job done. I noticed an air of despondency, even failure…. An expensive MEWP on site, which we couldn’t use too.

Our health and safety hero – Ryan Shann (right), with Bryan Hindle (a tin of SPAM makes Ryan smile)

Celebration.

The next day was our weekly de-brief. Each team reports to all about their week and what they learned from each project. Ryan told all that he had a ‘problem’ on the job in Leeds….

At this point I interjected and was able to explain that contrary to thoughts doing the rounds I was proud of Ryan and delighted with the way he and Adam handled the situation. I was also thankful to him for stepping in and doing the right thing.

I have spent the past few years trying to develop a positive health and safety culture in Brick-Tie. It is a never ending job. What the events this week show is that our culture is taking root as it matures. We all felt real pressure on site. We all wanted to help the client get the job done. There was a real chance that at the crucial moment that pressure could have resulted in a dangerous activity taking place. Ryan, Adam or another could have been hurt.

That threat was lifted by Ryan’s confidence in being able to speak his thoughts and by my willingness to listen. This is what a good safety culture needs to do – spread through every level of the business so that health and safety is everyone’s business and all can speak up.

Nevertheless, he was still a little worried about what his ‘boss’ thought. To be honest that worried me. This is why I needed to think carefully about what had almost happened. I analysed my part in it. I realised that when I wrote my on-site RA and method statement I didn’t allow for the fact that I was basing my assessment on a ‘ground level’ view. I did consult Ryan and Adam but they too were looking up at what we thought were thin, lightweight masonry units. I should have attended site again and made a further risk assessment once the platform was in place. That way Ryan would have the written instructions to do what he did automatically. I was wrong in not doing that, but Ryan saved me (and possibly himself) by doing his own assessment there and then – well done Ryan and thank you.

I also thought about how things can get out of hand when things change unexpectedly. This is a crucial moment on any job and the opportunity for things to go wrong. In this case it was obvious that Ryan and Adam felt the pressure to perform and get the job done. I played my part in applying that pressure without realising what I was doing. Ryan has been with me for many years; long before I got the health and safety bug. At our Friday de-brief we agreed that “back in the day he’d ‘av just done it.” So what has changed?

We’re much safer now

We are now a much safer place to work than we were in the noughties. We are not perfect, nobody is. Errors and omissions are part of life. This is why we need each other so that when the pressure is on and one of us drops the ball, his team mates have the training, motivation and confidence to pick it up.

It’s why Ryan was named a ‘Health and Safety hero’ this morning and it’s why I couldn’t get the grin of my face, even as I told the lads that I had made a serious mistake.

I’m so proud of my team and the real efforts they have put out into making Brick-Tie a safe place to work. They have cooperated with enthusiasm. It’s a slow and a never ending job, but the events this week show that it is working.

Friday brings everyone to the office so our very own face fit tester (Sian Caley), caught up with Richard Waite for his mask face fit test)

Much more to do

But there is much more to do. I write this post for several reasons:

1. I want Ryan and the crew to continue to speak up like Ryan did this week
2. I want to reflect on what I have learned so that I can use incidents like this to learn how to improve my own health and safety performance and help lead others to improve theirs, using my experiences, both positive and negative.
3. I want to make sure that our current point of work risk assessments are improved and become more robust

I’m humbled by my adventures in health and safety. I’ve been a damp and timber expert for decades and many look up to me for  guidance in this. I’m used to knowing the answers to other’s questions. It’s a challenge to find that despite my six year long struggle to learn about health and safety at work – I have barely scratched the surface. I’m realising that health and safety law, standards, controls and procedures are all subject to the vagaries of human behavior. Great health and safety is built on behavioral studies. They are central in planning and organising for a safe workplace.

I hope anyone like me, with responsibility for the safety and health of others can learn from this week’s safety issue.

Play safe,

DryRot.

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Leading building preservation specialists attended the Property Care Association (PCA), Northern regional meeting in Manchester yesterday.

These regional meetings are a chance for PCA members to hear what the PCA is up to on their behalf and share ideas and best practice in building preservation.

PCA chairman, Andrew Bradshaw introduced the event, with assistance from PCA technical officer James Berry.

Dave Cook on the exciting developments in domestic ventilation

Building Preservation and constant improvement

It’s refreshing to see very busy people taking time to discuss raising standards; sharing their skills and experiences. First up was David Cook, who explained how his efforts in the PCA ventilation Group are bearing fruit. Dave told us that the new code of practice for domestic ventilation has now established a benchmark for best practice in domestic ventilation work. His story is like that of many members, in that over the past few years he’s seen enormous strides in quality and delivery of effective indoor air quality, via excellent training.

Neil Marsden then gave a passionate and uplifting assessment of the PCA apprenticeship scheme. The ground-breaking apprenticeship program, delivered in the PCA’s dedicated training facility by Neil and his team, is already producing great results.

Neil Marsden brought us all up to date on the PCA apprenticeship scheme

Some of the members (like me), were also keen to share how their businesses were already benefitting from the improved skills and confidence engendered in those employees who’ve been lucky enough to attend the course. 

The clear majority of technicians in the industry have been taught ‘in-house’ with the odd external course thrown in. The NVQ 2 course, validated and supported by CITB gives new starters and established technicians their first chance to step-up the ladder and forge a career in building preservation. This is a firm foundation the industry can build on.

The entire PCA ‘back-office’ are to be applauded for all the hard work, which has gone into developing, funding and then delivering what is really a watershed for the entire industry.

University College London and the Property Care Association Knowledge Transfer Partnership (KTP).

Dr Fernando Sarce Thomann is the PCA’s newest team member and was on hand to introduce himself and take members through his role in the new KTP.

Fernando takes us through the PCA/UCL Knowledge Transfer Partnership

His presentation was an overview of the  KTP, where academic and business interests merge to work together. His chief skills lie in his deep understanding of building dynamics, where water vapour is involved. He has studied movement of water vapour through porous materials and as a trained Architect he is able to draw on his academic skills, alongside his love for buildings.

There was plenty of enthusiasm on show as he warmed to the task. It’s very clear that those members who are involved in the KTP (all welcome), will enjoy working with Fernando and together, we’ll all learn a great deal.

The indoor environment is becoming dominated by unintended consequences of ‘progress’. These include excess humidity, low temperatures and complex changes arising from retro-fitted insulation, as well as social change. Working with UCL, PCA members hope to provide tools and protocols to help specialists address these issues effectively. Diagnosis and remediation measure will be enhanced, putting PCA at the forefront of damp diagnosis, where environmental effects are involved.

I can’t wait to get to work with Fernando and my fellow PCA members. The next three years will be exciting and illuminating.

our PCA KTP leader gets warmed up…

Structural Waterproofing presentation.

Koster Waterproofing systems were on hand too, in the shape of Alex Lynn. Alex talked on structural waterproofing and gave a fascinating masterclass on the systems and methods Koster supply.

These ‘type A’ waterproofing systems are cutting edge materials,. They’ve been successfully used in some harsh environments, to stop water ingress through concrete and masonry units. Void filling, injection methods and important structural and safety considerations were explained clearly by Alex.

Koster’s technical manager Alex Lynn, in action.

Building preservation is evolving.

This was another great regional meeting, demonstrating once again that PCA members are up for the task of constant improvement.

I’m proud to be a member of PCA and can honestly say that engagement with the many training resources which PCA offer, has been central to my own personal development, that of my staff and my company. In the end, this delivers services and products which meet our clients demands. That’s what counts!

There was a good turnout of established, large and small PCA contractor members from across the North. These included Cook Group (Hull), Bar Group (Manchester), RTC (Blackpool) and Perfect Preservation (Merseyside). Manufacturer members were represented too, such as Safeguard Europe and Triton.  I was representing my team from Brick-Tie Preservation (Leeds). There were also independent specialist surveyor members like Neil Marsden and George Reese, among others.

Industry stalwart Malcolm Cook, of Triton, tells it as it is (as usual). Alex Lynn looks on.

For any PCA members interested in the KTP and how they can get involved please contact PCA in the first instance. I’m delighted to be facilitating the KTP as the official ‘go-between’ for PCA and UCL. As things lift off I would be happy to hear any comments or concerns PCA members may have. Building preservation is evolving fast and those who don’t want to be left behind, perhaps to face extinction, need to get on-board.

Dry Rot.

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Qualitative mask face fit testing – not valid once a beard is on the march!

Hi guys and gals of IOSH.

I have a quandary. Over the past year or three I have been hard at it; educating my construction workers about the dangers of silica dust and construction dust in general. I’ve walked the walk; investing time and money and leading by example. We have our own face-fit -tester and the boys are demonstrably ‘competent’.

However, try as I might, I can’t get them to ‘buy-in’ to being clean shaven. They know this weakens my efforts to protect them but, they are so adamant that their beloved facial hair must stay that I’m faced with a hard choice.

As their employer, I can insist they turn up clean shaven. I’ve used the analogy of being turned away from sites if you have no boots or helmet – we all accept that as sound practice. However, they keep explaining that their families hate them when shaven, their wives think they look ugly or childish – they feel ‘uncool’. One even said his daughter was frightened of him when he shaved, as he’s always had stubble. As for the ‘hard hat’ analogy, one of my guys summed it up thus “At least we can take our hat and boots off when we leave work – I can’t put my beard back on”!

Are they being childish? My initial thoughts are YES of course – “grow up”. However, it’s becoming clear that workplace stress and the mental wellbeing of employees is of vital importance too. How people see themselves, how they are consulted and engaged is important to their self-esteem and vital for mental stability. I consult weekly with them all and over the months it’s clear that this does matter to them. As an investor in people and the managing director I balance many management issues – not least staff engagement, alongside health and safety.

I’m a good employer and there’s no doubt my guys love their work. I doubt there will be any resignations if I put my foot down and make it a rule – “clean shaven or home you go”.

A hot lime mix outdoors and face fit tested dust masks enough?

Consequences of inaction

We know what will happen if I ignore the facial hair: Their health may suffer in the long run, despite our best efforts. They may decide to make a claim for damages. I may be prosecuted under HASAWA and CDM for failing to protect them. They will be successful, in that I always had the power to enforce a clean-shaven policy and in failing to do so I put them in harm’s way. Their claim may be reduced as I have all the evidence to show they contributed to their demise by ignoring advice on health and safety in contravention of HASAWA, in the information, training and such I delivered but – they will still be ill. The last point is what matters.

Consequences of action.

I may lose one or more crucially important employees who I’ve invested tens of thousands of pounds training and whom cannot be easily replaced. However, on a subtler basis I may cause damage to the company’s culture. I reason this because I’ve placed discussion and consultation at the heart of my management style for many years. This is not about just caving in to employees’ wants and needs. It’s about listening and balancing things; taking their advice and preferences into account.

Putting aside the respiratory issue for now. I think that if an individual measures his/her standing on how they look to their friends and family is entirely their concern. It’s like a sense of humour; you laugh at what YOU find funny. This cannot be changed on a whim or the dictate of others Thus there is every chance that a clean-shaven policy will tick the box for me on respiratory health; whilst leaving one or more employees with potential mental health damage over the coming months or years.

There’s also the effects on the individual who may feel ‘less’ of a person and the effects on employees in general, who may say they ‘work to live’ not ‘live to work’ and feel that they can make a choice – as adults, based on the knowledge they have and the efforts being made to reduce the risk of harm. Unlike managers and owners, they have every right to be able to leave work behind at five o’clock and go home without bearing the scars – a clean baby face, in this instance. Of course, the irony is that the scars will be there – in the linings of their lungs….

Squaring the circle….

In a factory setting this would be an easy problem – just use localised extract. But we’re talking highly mobile construction work here. My lads hack off plaster: drill walls and floors and yes – sweep up debris. These are often small ‘domestic’ situations rather than well organised constructions sites. We have dust suppression for some jobs, with M class vacuuming. They are trained to damp down and reduce dust at source and keep areas well ventilated but inevitably, there will be dust about their person. As far as I know there are no totally reliable and easy to use dust suppression kits for every situation (we use the excellent Hilti system but the on-tool adapters are not suitable for ‘small’ tools, favouring larger breakers).  Face fit tested dust masks are my guys’ last line of defence.

Vertical surfaces are the most problematic due to the angle of attack.

Maybe positive pressure hoods could be the answer? Facial hair is not a problem here as fresh pre-filtered air is fed directly over the users face. However, these are expensive and in practice they damage easily when they are being moved from van to van – site to site. Despite being designed to hang on the users belt, they are cumbersome and can be snagged on things and may restrict movement; there’s WRULD’s and Manual Handling to consider here.

Financial inducement

Of course, we cannot charge employees for anything provided for their health and safety. This is a given. However, some practitioners support financial incentives for health and safety ‘good practice’. I have my doubts on this and have worked hard to build a positive culture which by and large, the employees have bought into. Paying staff to work safe is the opposite side of the coin from charging for equipment or financially penalising failings in safety – a route to hidden incidents and a divisive environment.

Look at the stubble on that lot!

As a new health and safety professional in a small firm I have no peer group or internal mentor so I throw this out there for constructive comment…..

Bryan.

Expert Witness Training via the PCA – any good?

Yesterday I was at the Property Care Association HQ (PCA), to attend the Writing Expert Reports course.  This is one of the growing number of specialist additional courses the PCA have been adding to their already extensive suite.

Lynden Alexander of Professional Solutions delivered a fascinating day, for a diverse range of PCA members. These members included specialist contractors, independent surveyors, waterproofing experts and invasive weed specialists too.

Lynden gets to work with a well attended class

Clear communication.

Virtually all PCA members write reports and it’s essential that their clients understand the content of them. However, writing reports as an expert for use in court, requires another skill set. Lynden is a Forensic Communication Consultant. I must admit that I haven’t come across this job title before, though now that I have, I can see why people in his role are so sought after. The day was an eye opening introduction to the vagaries of writing reports for use in litigation.

Clear communication is the stock in trade of any professional, however we soon found out that in litigation, even the slightest hint of a mistake or, an ambiguous sentence or two, can and will be pulled apart by a barrister; in court it pays to be precise.

The thing which surprised me was just how easily Lynden was able to break-down seemingly precise statements. He quickly raised doubts about the meaning of what to me, were apparently clear sentences. He demonstrated how experts can fall foul in court, merely because they are used to talking to other experts. In effect they will become used to their own ‘context of obviousness’.

The above leads to habitual sloppiness in descriptive writing. Crucial details may be missed out, because the writer simply assumes that the reader will understand the finer implicit points, which the writer finds ‘obvious’.  Such assumptions not only lead to genuine misunderstandings; they also allow clever barristers the opportunity to exploit them and, thus break down the technical arguments the expert has made.

Who would have thought that CPR 35 could be fun?

CPR  35?

For those who aspire to make a living from acting as an expert witness, the day was a treasure trove of information. The Civil Procedure Rules were talked through, with Lynden pointing out areas where common errors and omissions lead to problems. He’s vastly experienced in this field and was able to use real case insights to back up all of the points he covered. These ranged from the importance of not allowing instructing solicitors to ‘parachute in’  weak and unsubstantiated conclusions, to making sure initial instructions are clear from the outset.

Report writing – a crucial skill for all surveyors

At this stage of my career; running a busy contracting firm, I have  no desire to promote myself as an  ‘expert witness’. To do this would require my clients to ignore the clear conflict of interest I’d have, were I to give any advice on projects where fellow contractors were involved. However, the skills Lynden was helping  us all refine; accuracy, readability and clear unambiguous writing, sit perfectly with a specialist contractors daily work. The day certainly helped me look again, at my own shortcomings, in relation to application of  ‘Bryan’s context of obviousness’.

Blog readers will know my grammar is terrible, but after the day with Lynden I discovered some useful hints and tips, which  I can use to help get my messages across more clearly.

In summary the course will be a very useful day for any experienced surveyors, whether or not they intend acting as a court expert. My own trip to Huntingdon was money and time well spent. Well done PCA and Professional Solutions.

Dry Rot.

For readers needing an independent expert report, please don’t contact me. The Property Care Association web site has a useful find a specialist section, where independent surveyors and consultants can be found. If you need a Yorkshire based damp, wall tie and timber decay specialist contractor, with some level of expertise, do please have a look at my little firm… in Yorkshire.

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There are many reasons why it may be necessary to carry out remedial wall tie installation. The most common reason is wall tie corrosion, where the original wall ties were inadequately protected against rusting. Poor galvanising and the use of bitumen paints was dealt with in the early eighties and these days, wall ties are stainless steel.

In the bed-joint the wall ties looks rusty – when wrestled out with a chisel, the true extent of corrosion is revealed

Other reasons for remedial work include incorrect installation during construction; missing ties or ties which are too short to provide sufficient embedment in one or both leaves of a cavity wall.

So, what can go wrong when remedial wall ties are installed or wall tie replacement undertaken? First things first – which remedial wall tie should be used?

Which cavity wall tie?

A good place to look at the different kinds of remedial wall ties and their advantages and disadvantages is the Building Research Establishment Digest number 329 (2000). This is available vid the BRE shop. It has a useful explanation of the basic types such as:

• Mechanical expansive ties – these work by being inserted into a pre-drilled hole and then expanded to secure them in one or each leaf (combinations are available, which offer mechanical expansion on one end and perhaps a resin fix at the other)
• Resin bonded Ties – a wide range of Helical and stud/bar based stainless steel rods, which can be inserted into clean pilot holes already filled with resin on the inner leaf and injected in the outer leaf after insertion
• Friction fix, or Screw-in type remedial wall ties
• Grouted sock anchors, where a fluid cementitious grout is injected, either through the hollow rod of the tie or via a dedicated feed tube – the grout being retained in an expanding sock whilst in its fluid form and then curing to a rigid mechanical/adhesive fix.
• Specialised remedial ties for use where one leaf of a wall is missing or bricks are removed to expose the remote leaf (sometimes called starter ties). These may be mechanical, shot fired (steel only), Screw-in (timber frame) or resin bonded.

Which of the above type are needed will depend mainly on the construction of the walls. Mechanical ties need to be installed in sound, strong materials; brickwork, reasonably dense blocks or concrete. In softer materials mechanical ties may offer reduced performance due to the increased stresses they apply. In these cases a non-expansive remedial tie, such as a resin bond item, friction fix or grouted sock type will offer greater reliability.

For hollow units a specialist should be employed to help choose and possibly proof test the proposed tie system. It is important not to simply choose a remedial system on cost or availability. Getting the right tie is crucial.

A second attempt and this mechanical type remedial tie has failed (soft inner leaf material)

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A word of caution – Cavity Wall Insulation.

Where cavities are filled before remedial wall tie work is done, special care is needed. Simply drilling holes through the insulation will cause some compression and contamination of the fill. BRE 329 (2000) offers advice on reducing this. Failure to take existing CWI into account will leave the installer liable for any damage arising from dampness or mould. Penetrating damp and cold bridging could arise through shoddy remedial wall tie installation.

BRE 329 (2000), gives vital information, comparing cavity contamination in relation to drill bit size and drilling machine type.

Installation of remedial ties can be fraught with problems and there are well documented cases where remedial work has been defective. Here’s a checklist to help the installation go well:

1. Make sure that the ties have been chosen with a good methodology – not just picked out of the air.
2. Make sure the proposed installation method agrees with the data sheets from the manufacturer. That all of the required fitting tools, tension testers, resins and torque wrenches are on site and calibrated where required. Agree the performance criteria first – do you need 1Kn or more?
3. The right drill bit diameter and length. Rotary hammer or percussion?
4. The installation density is dictated by many factors – make sure this is agreed in writing.
5. The work is not complicated, but once installed there will be little opportunity to check that the system works – so build-in a testing and inspection routine. Ideally choose a contractor who is approved via recognised consumer schemes and trade bodies (Trustmark, Chas, PCA, The Wall Tie Installers Federation, Which? Trusted Traders etc).
6. For guidance a RANDOM 5% test of the remedial ties is about right, for a one-off domestic property. Where multi-storey and large projects are involved this may be reduced over time, depending on the success of the testing early on (it may also increase if defects are found).
7. Record the tension test results as work proceeds
8. A guarantee should be asked for. Insurance is available to cover remedial wall tie work for up to ten years (GPI or similar).

What can go wrong at wall tie installation stage?

This tension test rig gauge demonstrates that a ‘pull’ of 1KN is being resisted by the remedial wall tie.

Tension tests are not reaching the agreed performance level.

If for example the ties are achieving 800N rather than 1000N?

All agreed proof tests should already include a ‘factor of safety’. Is the actual level still within this? If so then it may still be sufficient. However, in these cases the proportion of tests should be increased to make sure that the 5% at 800N are not the best of the ties. The factor of safety includes allowance for reduced performance. If you are now testing at the minimum – at least 20% should be checked. This could be reduced over time as the work proceeds, provided all ties are reaching the revised minimum.

What else could be done? It may be possible to improve the performance, without reaching for another type of tie. Check the installation procedure; the right diameter holes? Correct depth? Are the holes clean before the tie is placed? Is the inner hidden leaf a consistent material or does it vary? What about resins and grouts? Are they in date and being mixed and injected correctly? Has the width of the cavity varied, so that the embedment has been reduced – perhaps a longer tie of the same type will improve matters?

If refining the installation does not produce a significant improvement there are now two possibilities:

1. Change the tie specification to another
2. Increase the installation density to account for the reduced performance.

The new replacement tie will depend on the mode of failure. Increasing installation density should be done with the agreement of a structural engineer. The Engineer will supply the density increase via calculation. This is important because if the installation density is increased too much, this can lead to adverse unintended consequences. For example too many ties may introduce excess rigidity across the cavity in a vertical and tangential direction, which could cause cracking. If the density is not sufficient the system may not provide enough support for the external cladding – an engineer will know this. Is it wise for example, to increase density, when there is cavity wall insulation present? Of course it isn’t.

If the tests show a very high failure rate then abandon the remedial system and go back to the beginning. This is very rare in cases where a good methodology has been followed at the start. However, if remedial wall ties are just chosen because ‘They were in stock’, my mate said they’re the best or, ‘They were the cheapest’ it is quite likely to happen.

The Law.

All construction work is now subject to The Construction (Design and Management) Regulations 2015. Yes, even small domestic jobs on your street. The contractor should always provide the client with a health and safety file on completion of the work. This must include the type and number of wall ties installed. Anyone who may interact with the work in the future can take account of the presence of the tie system via this file. For example if a house fire has occurred, this could weaken a resin bonded tie system, which should then be checked. Carrying out further alteration to the property may also disturb a remedial system, particularly if parts of a wall are demolished.

Wall ties involves work at height – always work safe.

Every remedial wall tie installation involves work at height. This is a hazard to the wall tie technicians and potentially, those who are at ground level. Health and safety is everyone’s business. However, it is also a useful barometer when deciding how diligent a contractor may or may not be on site. Good preparation and care for health and safety is a legal requirement, with stiff penalties for non-compliance. Even so, poor safety and health care is common on construction sites, especially domestic and residential projects. Bearing this is mind it is fairly sound for clients to deduce, that a contractor who cuts corners with health and safety anyway, despite the risk, will pay even loss attention to work, which he can hide and which may not be found wanting, until long after he’s left site.

I hope the above basic advice will help small builders, homeowners and developers make sure their remedial wall tie installation projects are a success.

Bryan.

Here are some useful links to other posts on wall tie installation and wall tie corrosion too. You may also like to visit my own wall ties company pages, particularly if your project is in Yorkshire. If you have any questions about wall tie corrosion, do please drop me a line and I’ll do my best to help you. For a very detailed analysis of the common parts and physiology of wall ties try this post.

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The launch of the UK Centre for Moisture in Buildings

Last Wednesday I was in London for the launch of the UKCMB. The launch was at the Roberts Building, University Collage London. About 100 interested parties were invited along to hear about the UKCMB and find out how they could get involved with its work. I was there with PCA CEO Stephen Hodgson.

The UKCMB is an independent, not for profit, public good organisation run by University College London, the Building Research Establishment (BRE), Heriot Watt University and the London School of Hygiene and Tropical Medicine.

This was Neil May’s opportunity to introduce us to his friends and fellow dampness in building experts from Lund University, Sweden. The Swedish team were headed by Prof Lars-Erik Harderup, with his team; Dr Magnus Ahs and Prof Jesper Arfvidsson.

The Swedish National Moisture centre is based in Lund University and has been at the core of a real revolution in the handling of dampness in buildings in Sweden. Neil is keen to learn from their experience and create a similar centre, here in London, where skills can be built and knowledge shared.

The FuktCentrum

An explanation of the work of the FuktCentrum in Sweden

During the morning sessions we were treated to an in-depth look at the work of the Swedish centre and the activities of the FuktCentrum as a whole. It was fascinating listening to the story behind the creation of the FuktCentrum. It basically arose in response to the avalanche of dampness issues effecting new buildings erected in the past ten or 20 years. Prof Harderup explained how people were becoming exasperated with the serious and unforeseen damp penetration and condensation defects, which presented within a few short years of completion.

Something had to be done to improve design and site practice. The improved research and the training and qualifications that this engendered, has really improved professional standards, where dampness in buildings is concerned.

UKCMB – launched!

A wide selection of academics, professional surveyors, insurers and others at the UKCMB launch

After lunch Neil took the stage to outline the aims of the UKCMB, its organisation, program, current and future projects. These range from on-site testing of environmental checks, alongside sponsor Polygon, as well as planned research with the Property Care Associating as part of a planned Knowledge Transfer Partnership. Neil challenged delegates to come forward with their aspirations and problems so that together, UKCMB and the wider industry can work to improve understanding of moisture in buildings for the ‘public good’.

The sessions in the afternoon included a series of brainstorming discussions on:

• Retrofit risks and unknowns
• Flooding and Escape of Water
• Timber in Buildings
• Improving moisture safety in Buildings
• Moisture and people in Buildings (Health and building use).

I managed to attend two of these and was taken by the breadth of opinions and also the enthusiasm of those in attendance.

Research into dampness in buildings is at the heart of the UKCMB

A call to get involved with UKCMB

Neil closed the day, repeating his call for delegates to get involved by prompting research goals and offering help.

The Swedish connection is a good fit. I have to say I was a little sceptical, but after listening to the Swedes I came to see that there really is a strong correlation, between their past experience and what we practitioners are seeing out in the wider world of surveying. I can’t wait to get involved and will be sending on some ideas and data I’ve collected this past few years.

I hope and expect that the UKCMB will enable a leap forward in knowledge and skills in diagnosis and treatment of dampness, as well as pushing design forward, to help avoid issues developing in the first place. Anyone wishing to get more information or, who need research or want to offer help should contact Neil May.

So what does the UKCMB mean to us surveyors? Well I think that at last we’ll have a cutting edge resource for sharing and learning about dampness in buildings. It means that those of us who are exploring ways of improving outcomes for consumers with dampness problems will have help at last. We won’t be on our own – that must be a good thing.

Have a look at this cases study carried out by one of my surveyors this past winter, using humidity and temperature data logging to help a landlord with a perennial mould problem. Science has a part to play in our day to day work.

Dry Rot.

For more on the cutting edge damp diagnosis PCA members are involved in try my good friend Ross Charters’ blog – https://blog.completepreservation.co.uk/2016/04/07/why-is-there-a-damp-patch-and-staining-on-my-chimney-breast/

Salts and chimney breasts

https://www.preservationexpert.co.uk/relative-humidity-and-vapour-pressure-which-is-best/

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