Select Committee on Environment, Transport and Regional Affairs Minutes of Evidence

Examination of Witnesses (Questions 85 - 99)




  85. We can continue with the third session this morning into the potential risk of fire spread in buildings via external cladding systems. Gentlemen, can I welcome you to the Committee and ask you to identify yourselves for the record?
  (Dr Ledbetter) I am Dr Stephen Ledbetter from the Centre for Window and Cladding Technology at Bath University.
  (Mr Buntain) I am Chris Buntain. I am technical manager of a company specialising in the development, manufacture and installation of insulated cladding systems.

  86. Thank you. Do either of you want to add anything to what has been said so far?
  (Mr Buntain) I think it is important from the outset that we clarify what the situation is with regard to the Irvine block. The Irvine block was not overclad. The Irvine block is a block of concrete common throughout the whole of the United Kingdom. It is made of concrete and it is as non-combustible perhaps as you can get within the building industry. It certainly will not catch fire. It was not overclad by any material at all. It had had its windows replaced by the local authority using a plastic window and it was the full height plastic window units within the block at Irvine that caught fire and the panels below the window, but not overcladding which the building is assumed to have had by some people. It was not overclad. It had a composite window unit which caught fire.
  (Dr Ledbetter) There have been tests developed for fire and there has been research into the behaviour of fire. It has largely been by fire engineers and not by building engineers. This misunderstanding of the type of cladding seems to be rife amongst those developing tests. I would emphasise the point that we need to be clear as to what types of construction cladding we are discussing at any stage.

Mrs Ellman

  87. What is your assessment of the risk of fire in external cladding systems?
  (Dr Ledbetter) My own assessment would be that there are very few incidents that are known within the industry. Obviously, not all incidents are reported back to the industry from the Fire Brigade and from local authorities but we do always resort to talking about one or two incidents which are notable, notable because there are not very many I suspect, and notable because of course in a high rise building there is a greater risk. It may be a very rare event. It is the same if we get an accident with an aircraft, where the intensity of the event is great but the number of deaths is not that great compared with the number of people generally killed in, say, road accidents. What we get is a concentration of people's minds as to what could be a large but rare event and I suspect that there are more people injured and killed by fire in low rise buildings.

  88. You think the dangers are exaggerated?
  (Dr Ledbetter) If we see a fire in a high rise building, we perceive that it might become a large fire. That is probably more a matter of perception than reality. I am not aware of many incidents of fire spreading through high rise buildings, particularly through the cladding, by burning out and burning back in.
  (Mr Buntain) Before any research is undertaken, we should get a perspective on this thing in so far as the scale of high rise incidents is concerned with regard to cladding installations. Like Dr Ledbetter, I do not know of a great number of incidents of fires which have taken place in multi- storeys or indeed in any overclad buildings. I know of some but there are not very many. I would suggest also that we should call on European experience which is perhaps 20 times more in terms of the surface area of buildings that are overclad with potentially fire reactive insulants. We should have a look at Europe and find out what exactly the scenario has been there and whether there have been situations which have given rise to concern. For example, typically, the German market is 20 times larger in overcladding terms than our own United Kingdom market per annum. Therefore, their experience is at least 20 times more than ours. The Germans also pay great attention to detail in terms of the soundness and fitness of their materials. They will test absolutely anything before it is assessed as being fit to put on a wall and it would seem to me that it would be appropriate to have a look at this German and continental experience more widely to find out what the extent of the problem is and how they are dealing with it and how they are addressing it; and also to see whether there is any pending European legislation coming about which might address this problem and some test procedures which might come through the European technical lobbies which might address this problem.

  89. Are current regulations adequate?
  (Dr Ledbetter) I believe that the current regulations are adequate in as far as they can be. One of the problems with regulation is that it is very difficult to be specific and write regulations which embrace all forms of construction. There is a very wide diversity of new construction and I believe that is what we want as a country in terms of having a diverse cityscape and diverse forms of architecture. It is more complicated with overcladding where we go back to existing buildings and we overclad them. Then we end up with an even greater diversity of forms of construction. What we have done at the time being is write regulations which generally embrace the intent of preventing the spread of fire. We are looking at developing methods of test. To date, we have developed methods of test that are specific to just two types of building construction and not to all forms of building construction. Therefore, to write tighter regulation would be difficult because it would not embrace all the buildings that we currently construct.
  (Mr Buntain) There has been some inference, if not suggestion, that full scale fire tests have not been carried out on fire reactive cladding systems in buildings. Some 10 or 12 years ago, a test was carried out at Cardington under the auspices of the Building Research Establishment, albeit it was only to a three storey structure at the time, but it was full scale and it did have largely the types of cladding system which are predominant in the field of overcladding, particularly on multi-storey buildings. The fire tests were carried out and certain conclusions were drawn by Building Research at that time relating specifically to fire fixings which would restrain and retain the cladding on the wall while the fire was being extinguished; and also to find out how these systems reacted in a real fire situation. When I have a look at the test equipment and the proposed test regime which is now being suggested, I see many similarities to something which did occur about 10 or 12 years ago. It is wrong to think that we did not take fires seriously then. Those of us, including myself, who are involved at the sharp end of designing and installing these systems did have a Defects Action Sheet produced by Building Research which we have incorporated into our high rise designs ever since that fire test was carried out. It is not embodied in law; it is a recommendation but most manufacturers put it in. Fire stopping in multistoreys is something that is done in these systems.

  90. What could be done further now to minimise the risk of fire damage in the situations you describe?
  (Mr Buntain) Fire damage is not the problem. Nobody is really interested in retaining the building. The building will be damaged whether it is concrete, whether it has plastic windows or whether it has polystyrene on its outside. It will be damaged by fire. The fire authorities—I think they would agree—have two prime concerns. One is the safety of those people escaping from the fire and, secondly, those people who are fighting the fire. If the building survives, well and good, but the main concern is to get people away safely. If the building is, to a large extent, non-combustible or highly fire resistant—and the two words again should not be confused; you can get a material which is non-combustible but it need not be fire resistant—it is very significant in giving the fire authorities confidence to fight that fire in the knowledge that the building is not exacerbating the fire.

  91. What could be done to secure that type of building? More regulation? Different regulation? Something else?
  (Dr Ledbetter) We currently have a position whereby the industry has its own guidelines as to how it puts fire stopping in cladding, how it uses materials that are not ignitable. The respectable part of the industry obviously works in that way. That is not to say that all of the industry does but most buildings that are high rise are supervised in their construction or renovation by professionals. Therefore, we do get that check from the professionals involved in design. There is currently some confusion. We have a number of methods of test being developed and to give guidance on that at the time being or to embody it in regulation would be difficult. We have a method of test developed by the Building Research Establishment which is currently up for discussion as a proposed British Standard. I was in receipt only yesterday of documents from the European Technical Committee where the Germans are requesting that a test be developed, a slightly different test. We have also had a test developed by the insurers, by the Loss Prevention Council, and all of these are different tests and all of these tests relate to different forms of cladding. I have personally been asked by all of these groups to advise them on the forms of construction because they are essentially fire engineers. I think there is a need for the constructors and users to sit with the fire engineers and develop recognised tests before we can advance with regulation. In the meantime, we have to work on the best advice that we currently have and our lengthy experience in this field.

Mrs Dunwoody

  92. Why are you making this artificial distinction? Why should your group be more accurate in their assessment, which is what you seem to be implying?
  (Dr Ledbetter) I am not suggesting that my group would be more accurate in its assessment. I am suggesting that there are different groups involved in this issue. There are some people who understand fire and the spread of fire from largely traditional forms of construction. What we have to understand is that the method of cladding buildings has changed radically in the last 20 years, particularly so in the last 10, where we have developed new systems of building. We need the manufacturers and developers of those systems to sit with those who have been studying the other aspects, such as fire, in a more traditional setting. We need a cross-industry discussion between those developing tests, those constructing and those developing yet further systems.

  93. Are you saying that you are not fully represented on the Ministry's committees and on its consultation documents?
  (Dr Ledbetter) The way in which the tests have been developed is for specific solutions to specific problems. Nobody has actually looked at the problem in its generality.

  94. So you do not discount the evidence that we heard this morning; you are simply saying that it can be interpreted in a different way?
  (Dr Ledbetter) I apologise. I was unable to be here for the earlier part of the proceedings. There have been tests developed which look at specific forms of construction, not at all forms of construction. We should make a determined effort to sit down at industry, the test houses, the users and manufacturers, and discuss this issue.

Mrs Ellman

  95. Are you saying that this should be left to the industry itself or certain sections of the industry?
  (Dr Ledbetter) No. I am suggesting that we should have the normal method of developing technical standards that we use in this country. One method of test has just now been put forward for discussion as a proposed British Standard and I for one think it should be broadened to cover other forms of construction so that it could then be used within regulation, if that is what was desired.

  96. Why would you say that fire spread so quickly in Irvine, which you have mentioned, and in Knowsley in Coventry?
  (Dr Ledbetter) Certainly in the case of Knowsley, that was an older form of construction and there was, I believe, inadequate fire stopping. We have learned the lessons of that incident.


  97. Are you satisfied that fire stopping has been put into all the tower blocks where it is needed?
  (Dr Ledbetter) No, not at all. I am sorry if I have misled you but I am talking about new forms of construction and new forms of overcladding. I am not talking about the existing housing stock which I think is a separate issue.
  (Mr Buntain) I think this is something which will impact on the future of building construction. I do not know whether this Committee deals with it or not but insulation standards are going to be very seriously looked at in terms of the increased insulation standards to cut down CO2 emissions and get things like affordable warmth and so on. With these insulation products which will have to be used, many of them on the exterior of buildings, the only place to put them probably, the whole question of the fire issue is very important. Unless the means of protection which are these fire barriers, which are recommended to be put in, are put in or unless a non-combustible insulant is used, for example, the building is at risk but that is not normally the case. Could I suggest finally that perhaps legislation may not be the route to go down because there are other things which regulate these systems. There are things like the British Board of Agrement or WIMLAS which are test bodies which do test these systems and which do test for wholesomeness in systems for use in buildings. It could be that the remit of Agrement or WIMLAS was extended to cover the kind of testing that you are talking about, because most people who are serious about being in the business of overcladding buildings do get a WIMLAS certificate or a BBA certificate for their product.

  98. When we talk about public safety, is it good enough to refer to what most people in the business think? Do you not feel there should be better regulations?
  (Dr Ledbetter) There is currently regulation which sets out the intent that fire should not spread through cladding, but it would be impossible, I believe, to write regulation which would actually be applicable to all forms of construction because we do not currently have agreed methods of test against which we could prove all forms of product and construction. That is the reality. Until we can develop those tests, it will be very difficult to frame legislation.

Mr Cummings

  99. This Committee may wish to recommend that the draft British Standard resulting from the test devised by the Partners in Technology programme at the Fire Research Station become mandatory, at least for new cladding. What would your reaction be to such a recommendation?
  (Dr Ledbetter) I believe that the test has been developed for a restricted form of cladding which is overcladding of buildings containing small glazed areas within concrete or masonry walls. There are many other forms of construction, notably curtain walling. This is the kind of cladding which appears on hotels and a number of residential blocks. I think any legislation which was framed in terms of residential properties would have to cover a wider variety of cladding systems.

previous page contents next page

House of Commons home page Parliament home page House of Lords home page search page enquiries

© Parliamentary copyright 1999
Prepared 17 August 1999