Diary of a dissatisfied customer
 
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The Problem

This is not about British Gas or Cavity Wall Insulation per se. It is about the inferior cavity wall insulation job carried out at my home for which British Gas is responsible. The cavity wall insulation involved is one particular type and what applies to this particular type may not apply to other types of cavity wall insulation. British Gas supplied me with a document produced by the British Board of Agrément (BBA), a document which the British Board of Agrément had previously refused to supply me with. The said document will feature prominently in this section of the website, where I hope to demonstrate clearly why the work is substandard and why the document itself is substandard: I am a construction professional used to examining everything. I take nothing at face value and neither should you. Do not be dazzled by a fancy looking document. Look at the evidence. Look at the facts.

For the avoidance of doubt, the cavity wall insulation product itself may be the best on the planet. This is not necessarily about the product used but installation of the product used, which is obviously beyond the control of the product manufacturer.

History

I have had to endure tragically pathetic and indeed naive arm-waving by British Gas and others during their efforts to befuddle or con me into accepting an unbalanced compromise. What are in my opinion classic commercial cowboy tactics. Latterly that has included trying to bring a product expert to talk to me. I do not at this stage have a problem with the product. The facts are plain for all to see and the response to those facts self-evident to any construction professional. There is a substantial void where there is no pre-existing construction reason for the void. Given the evidence below it is clear there will probably be further voids and given that information, the response as I have said is self-evident. The self-evident response will be implemented and cannot be avoided.

I am devoted to energy conservation in order to save money on fuel and bring comfort in my later years. In connection with that I have invested a lot of time, effort and money. My money and only my money. Because of that I am not inclined to be fobbed off by corporate bullies who clearly have no interest despite the window dressing of their self-aggrandising public image.

The Void

The window opposite is the one which had a damaged window board (internal window cill) that was removed for replacement. Removing the window board revealed the void in the cavity wall. That void is depicted by the dotted line. Obviously the void is not of regular shape so the shape shown is approximate. There are a couple of not very good images you can look at. Ultimately endoscope images will supply the proof.

Subsequent checking revealed two injection points depicted by the blue dots. Here we need to be careful. The existence of two apparent injection points does not necessarily mean they were used. The two injection points fit the pattern of fill. However, whatever the pattern used, a void was left and there is nothing else in the void to suggest a construction fault such as a clump of mortar. There are no obstructions. .

Discussion on the pattern used is therefore pointless at this stage. The priority is to discover the cause of failure. As it happens I was in attendance when the work was done and noted certain matters in connection with the process. The process of obvious academic interest to me as a construction professional.

It will now be necessary to create a series of pages under this heading. The pages concerned will have a link back to this page only. You can either skip those pages for now or read them and return to continue reading this page. Using this technique will I hope aid understanding.

I already know that the injection process itself is crucial to understanding the problem. Again we should not jump to conclusions as to the cause. We need to examine all available evidence. That evidence is surprisingly broad. For example it may or may not be the fault of the operatives carrying out the work. Unfortunately the BBA document is technically poor and answers are needed in connection with that. I have no doubt the previously experienced obstruction to my enquiries will continue and recourse to the County Court may ultimately prove necessary in order to obtain answers to questions posed about the process.

We have to be on our guard against what may prove to be industry-wide collusion or corruption. If the latter applies we may never overcome that without official support and may need to seek an alternative cavity wall insulation material / process which reduces the risk of failure, for example beads or granules, as has already been whispered in my ear. The latter is being explored but first the process theory.

At this point in time I do not have access to details of the training regime for key card-carrying operatives. That may or may not throw light on this subject. I do not have details of approved apparatus used for the work. That would also help. As a basis for discussion we will assume that a correctly trained operative was in control and all the correct apparatus and protocols were employed throughout the work. With this in mind we will examine what was actually carried out or as we say in construction as-fixed.

With any investigation we have to be extremely wary of contaminating evidence. In this case evidence of failure is hidden from objective scrutiny by brickwork. However the matters that hinder objective scrutiny also protect the evidence from the risk of contamination or even sabotage.

It is now self-evident that failures can occur with cavity wall insulation. There is irrefutable evidence of one failure already at my home. There may or may not be more. That said, the nature of the known failure is such that we cannot in any way be confident it is an isolated incident. As I paid for filled cavities I will settle for nothing less.

The BBA document includes the following words:

the Certificate holder oversees the activities of approved installers operating under the BBA Surveillance Scheme for Cavity Wall Insulation. It is a requirement that the system supplier undertakes a minimum of four inspections per annum to each installer using their product and maintains records.

I received an inspection but there was no documentation associated with that inspection. I cannot therefore be sure what the inspection was related to. Internal or external audit. Either way the inspection visit was simply window-dressing for gullible punters, me being one of them. It should already be self-evident to any reader lay or otherwise, that the only viable method is thermography and someone wearing knee-pads.. The snag with that method is that it can be too good but we also need to be careful.

Following considerable correspondence from me in the early days, British Gas eventually and reluctantly suggested random boroscope testing. What was meant by random was not stated. How objective that would be was not stated. I already know enough now (I did not before this started) to undertake a not-so-random test that could produce a result in favour of the contractor. I was also aware then of the commonplace use of thermography and the apparently moribund CIGA.

 
 
This image is taken from the internet and serves to illustrate thermography. To be useful the camera used must be of suitable specification. Different thermal imaging cameras serve different industries and perhaps different purposes within industries.

Having obtained thermal images there is still the vexed question of interpretation of images. For example an apparently model insulated roof which suggests to the camera negligible heat loss could mean that the owners are away or the occupant is in fuel poverty and cannot afford to run any heating. Conversely a roof glowing with heat loss may be poorly insulated or hosting a cannabis farm.

One thing is certain. I am not competent to interpret images. I do not have the experience. That said, in this case, I know the extensive detailing on this property backwards so we are looking for contrasting areas on the same property or even the same wall rather than comparing different properties, which would certainly require more expert opinion.

 
I am competent to consider contrasts on the same property with the help of the photographer. But first the images need to be taken and that also requires great care. Some suggest thermography is a job for insomniacs. It must be carried out on a dry day very early in the morning before solar gain has a chance to affect contrast. The photographer also requires heating on for 24 hours, all doors open, large items of furniture moved away from external walls and, my choice, I will also remove the bath panel which will otherwise prevent that area from receiving internally generated heat quickly. The wall there is already suspect according to the drilling pattern actually used.
 
Another point of interest, none of my central heating radiators are on or anywhere near an external wall. I hold a view shared by Viessmann boilers that in a well insulated home radiators are not required to be on external walls; my comfort levels cannot be improved.

I was obliged to remodel my bathroom completely including the floor. I took the opportunity to insulate the floor after first dealing with any air-leakage issues (holes around joist ends). Finally as complete replastering was unavoidable I opted for insulated foil behind tanalised battens covered with plasterboard and skim to create an insulating low-emissivity air space.

There will automatically be a contrast with adjacent walls which have not been treated to the same additional insulation techniques, thus care is needed in making judgments. Differences in contrast on the same area of wall however might indicate a void in the cavity wall insulation. Specific instructions have been given that the camera used must be capable of spotting a complete void in cavity wall insulation. Not low density fill but complete absence.

 
 
 
To use this obviously home-made collection of colours as an example, the only part that has any significance is the colour B on colour A, a contrast on the same area of wall. That strongly suggests a weakness in the insulation at the point B. Please note it is not proof. The only way to obtain proof is to look. The only way to look is to use an endoscope and if a void is confirmed the only way to record and communicate details is by way of digital images.

As previously indicated, a large item of furniture set against a wall could give a false reading and suggest that part of the wall is better insulated than the rest. Or, that the rest is not as well insulated as it should be. We need to proceed with caution, examining all data. Hence the degree of detail offered relating to my home. That is the required detail in any construction investigation work. My kitchen under the bathroom was afforded the same attention to detail and, often still overlooked in 2012, so was the floor which traditionally has always been a massive heat loss. There is more but that will be covered elsewhere in due course when the results of the thermography survey are known. In connection with the latter, the forecast as I write is for the return of frost. The survey can then be carried out to best advantage.

 
 
 
 
ONGOING AND UNDER DEVELOPMENT WHILE THIS LINE EXISTS
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