HC Deb 09 May 1975 vol 891 cc1893-906

4.2 p.m.

Mr. Neil Macfarlane (Sutton and Cheam)

I am indeed grateful to have this opportunity of raising this subject under the Adjournment procedure. I am sure that the Minister will welcome this opportunity to debate the problems connected with the use of high alumina cement.

Those words—or the abbreviation "HAC"—are rapidly and relentlessly becoming a combination of misery, apprehension, worry and fear for thousands of people in the United Kingdom. I must make it clear that I am not an engineer. Nor am I a design consultant. However, I have the responsibility, as do all Members of Parliament, of representing thousands of people from my constituency. Today I speak not only for my own constituents but on behalf of a far wider franchise.

Many hon. Members have sought information through the Parliamentary Question procedure and letters to the Department. I have no doubt that my hon. Friend the Member for Ealing, Acton (Sir G. Young) hopes to catch your eye, Mr. Deputy Speaker, to speak for a short time, as does my hon. Friend the Member for Reading, North (Mr. Durant). I am sure that my concern over the problem which I seek to raise this afternoon is shared by hon. Members on both sides.

However, I was a little disappointed when I did not receive a reply from the Minister for Housing and Construction to my letter dated 18th April. Neither did I receive a reply to my letter dated 30th April—which again sought a meeting with the Department of the Environment —until I received a telephone call on 5th May from the Department of the Environment which recognised my desire to see the Minister to discuss HAC. I am sure that it was pure coincidence that this phone call came shortly after my success in the Adjournment Ballot was published. Indeed, this was followed by a letter a few days later. I hope—indeed, I am sure—that the Department is work- ing swiftly and confidently on the vexed problem of HAC

We know that high alumina cement has been used extensively in the United Kingdom as a construction material during the past 20 years. We know also that it has been in use in other countries. I understand that at the outset two of the great merits of high alumina cement—so the manufacturers claimed—was that it set quickly and, especially important, that it was resistant to salt water. These were no doubt two of the reasons for its tremendous commercial boom in this country.

What we now know is that concrete made with high alumina cement undergoes changes in its crystalline structure. This, among the construction and engineering fraternity, is known as conversion. This causes loss of strength, and this loss of strength can be generated by moisture or warmth.

Many professionals in the construction field have had growing concern about some of the methods and materials which have been used in design and construction for a long time. In February 1974 the collapse of the school roof beam at the John Cass School, Stepney, perhaps demonstrated their concern, and this near-tragedy sparked off the current alarm which is now so prevalent in this country.

It must be understood by those with anxiety about this matter that high alumina cement is a perfectly adequate cement when used properly, and it is generally accepted that houses built with HAC parts are not at risk. However, if high alumina cement is mixed incorrectly it can cause "rotting" and then the beam cannot take the strain. A recent letter from the Department of the Environment to local authorities advises that the risk of structural failure is small in buildings with HAC with spans of up to five metres, so that the risk of structural failure is probably confined to spans of more than five metres. Undoubtedly this crucial point is one of the dozens of questions which will have to be answered at some stage and to which the country will want to know the answers by the Department in due course, such is the anxiety at present.

Last week's Daily Express posed several pertinent questions in an excellent article which appeared over two days, but the most disturbing aspect was the fact that Professor Adam Neville of Leeds University, produced a published report in 1963 in which he warned of the possible dangers of HAC.

I see that, happily, Professor Neville is one of the five men appointed to the Government's emergency committee for drawing up the safety rules for HAC buildings.

I want to turn now to the reasons for the deep consternation which many people must feel. First, on 20th July 1974 the Department of the Environment wrote to all authorities stating that All existing buildings incorporating HAC must now be regarded as suspect, at least in the long term. I cannot but help wonder if this circular triggered off a little unnecessary alarm which spread surreptitiously and unofficially, as always happens with certain elements of the mass media. Local authorities have now compiled lists of suspect buildings, the newspapers have reported this fact, and this, in turn, has done nothing to allay people's genuine concern. A little news item has assumed gigantic proportions in the minds of many.

Thousands of home owners in my constituency and throughout the country have tried to put their property on the market and have been greeted with an opening question from a potential buyer "Does it contain HAC?" If the answer was "Yes", it is distinctly probable that the negotiations ended abruptly.

A home is the biggest and most important thing the majority of us ever buy, and it is only natural that caution is exercised. At the moment I think that caution has become distorted by the wretched bandwagon effect which, alas, is so often a feature in society today.

Then there are people seeking a mortgage who find that not all the building societies like to see the phrase "high alumina cement" in the surveyor's report, and a fee is wasted. There are people working in buildings which have stood the test of time—for two decades, perhaps—with HAC, but suddenly they develop concern because of the bandwagon effect. At present rumour and concern are rife and I am convinced that the Government have a clear duty to hasten their findings and urge upon the Building Research Establishment that the direction of its investigations warrants a 24-hour day until its research and advice is made known to this country. The cost to the nation could be enormous when taking into consideration the loss of amenity. There is also disruption of education and the concern of parents for the safety of their children. It is estimated that Birmingham alone could cost over £10 million to strengthen or replace the buildings. It is estimated that 22,000 buildings could well be involved. Newspapers and the mass media carry the claim that this programme could cost £2,000 million to remedy. The speculation is endless, in private, in the local authorities, and elsewhere.

I ask the Minister to convey to his right hon. Friend the Secretary of State the fact that there are serious accusations against the length of time and the methods being used by the Building Research Establishment to finalise its report. It might be better to assume that all HAC beams in excess of the 5 metre span are suspect. If not, tell the nation they are safe and dispel the worry. I cannot help but feel that one of the schemes which the Department should consider is the use of glass reinforced polyester. A glass reinforced polyester U-shaped beam can be installed around the suspect high alumina cement beam so that the new beam carries the entire load. The GRP beam would withstand any HAC collapse. Glass reinforced polyester's many benefits and properties will be well known to the Building Research Establishment.

I close by expressing a hope which I imagine is one held by many Members. The Government must do and say something quickly. Further testing is merely postponement. Further delay enables rumour, innuendo and anxiety to spread like wildfire. Not unnaturally, the mass media has seized upon the frailty of the scene, and the Government have a clear duty to restore a rational balance and dispel the low morale of many people within the community.

4.12 p.m.

Sir George Young (Ealing, Acton)

rose—

Mr. Deputy Speaker (Mr. George Thomas)

Has the hon. Gentleman the agreement of the Minister?

Sir G. Young

Yes, Mr. Deputy Speaker.

The House is indebted to my hon. Friend the Member for Sutton and Cheam (Mr. MacFarlane) for this opportunity to debate the problems which have arisen from the misuse of HAC in this country, and I am indebted to my hon. Friend for allowing me two minutes of his time.

I wish to raise two points. The first deals with who pays for the structural alterations to the schools and other buildings owned by local authorities, and who will bear the loan charges and other costs which may have to be written off if those buildings can no longer be used in the way in which they were originally intended. In my own constituency, Ealing Mead school can no longer be used as a school because of structural defects, and provision has had to be made to accommodate the schoolchildren elsewhere. It is intolerable that the ratepayers in Ealing, who are reeling from the 63 per cent. increase in rates, should have to bear unaided the cost of remedying the structural defects which arose through no fault of their own and which are a national rather than a local problem.

I remind the Under-Secretary of State what happened after the Ronan Point disaster. The local authorities had built high rise accommodation to the technical satisfaction of his Department, but after the disaster structural alterations were required at great cost, and the Government recompensed the local authorities in that case because they recognised that it would be inequitable to let the burden fall on those local authorities which had built high rise accommodation. I urge the Department to adopt the same solutions to the problem of HAC as were adopted following the structural alterations which were necessitated by the Ronan Point disaster.

My next point concerns the 61,000 people in England and Wales living in accommodation in which HAC has been used. Those people find that their property is effectively blighted. They are unable to sell or move, and they face the evaporation of their life's savings. I urge the Minister to introduce as soon as pos- sible a system of certification so that those buildings which are not at risk can be authoritatively identified, and those properties which are at risk should be treated in the same way as properties which are affected by planning blight. The analogy is quite clear. Through no fault of their own but through the action of public bodies they find that the value of their accommodation is diminished. I therefore urge that they should be entitled to sell to the local authority or to the Government their properties at pre-blight value as in the case of properties affected by planning blight.

There is considerable concern in my constituency that the Department of the Environment Circular 271 referred to a working party set up to represent "all public sector interests", and made no reference to private sector interests. I hope the Minister will take the opportunity to reassure all the people living in these buildings that the Government will not sell them down the road and that they are urgently identifying solutions along the lines which I have outlined to solve the human and structural problems.

4.15 p.m.

Mr. Tony Durant (Reading, North)

I am grateful to my hon. Friend the Member for Sutton and Cheam (Mr. Macfarlane) for giving me the opportunity to come in on this short debate. I shall not detain the House for long, because we want to hear from the Minister.

I think I can summarise the information that we want by listing 10 points. First, we would like to know why the Department of the Environment continued to allow this cement to be used after the 1963 report, which we have heard mentioned today, and the experience of France. Secondly, why did the Department issue a circular on 20th July which caused considerable anxiety and panic? Thirdly, why is there delay on this report? We have heard that it is in the hands of the Building Regulations Advisory Committee. Could we not get this report sooner? Fourthly, when will the report be out? It should be issued so that people have some idea of the situation, particularly when they are trying to sell their properties.

Fifthly, how many alternatives have been examined for dealing with this situation? Have we taken all the advice that is available? Can we now free those beams which are less than 5 metres in length? Can we say that they are all right? If we can, that will help the situation.

Sixthly, why is there no system of checking these beams? There seems to be some argument about this. Surely the French experience should be brought here to see whether we can do the checking. Seventhly, do we know the size of the problem? After all, all sorts of buildings are involved—hospitals, offices, and so on—and many have been mentioned today. Eighthly, are the building societies refusing to grant mortgages on these buildings? There is some argument about this. Some societies are, and some are not. May we have an answer to that? Ninthly, can help be given, as was suggested by my hon. Friend, under the planning laws relating to blight? Tenthly, who will pay?

The Minister always gives us straight-to-the-point answers, and I hope that he will do so this afternoon.

4.17 p.m.

The Under-Secretary of State for the Environment (Mr. Gerald Kaufman)

With blandishments such as that, how can anybody resist?

The hon. Member for Sutton and Cheam (Mr. Macfarlane) and his hon. Friends the Members for Ealing, Acton (Sir G. Young) and Reading, North (Mr. Durant) have raised a matter of considerable topical interest and concern. The problems connected with the use of high alumina cement concrete are far-reaching, and I realise the concern that they are causing to property owners in both the public and the private sector. I welcome this opportunity, as the hon. Member for Sutton and Cheam expected I should, of explaining what the problems are and what we are doing about them.

Concrete itself is, of course, a very old building material, and examples of Roman concrete still survive. Most concrete today is made from Portland cement of which the basic ingredients are limestone—or chalk—and clay. The cement is mixed with sand or aggregate and water in varying proportions according to the type of concrete required. Concrete made from Portland cement is durable but it takes some little time to reach its full strength. In high alumina cement, as its name suggests, the main compounds are calcium aluminates. Concrete made from high alumina cement reaches its greatest strength quickly, and so it has hitherto appeared an attractive material to use to help to produce much-needed building components.

But, as we are now finding out, concrete made from high alumina cement is liable to undergo changes in its crystalline structure even when it is used in a normal environment. This process is known as conversion, and it is accompanied by a loss of strength in the concrete. This loss of strength can take place slowly or quickly. and the ultimate strength of the concrete when it is fully converted depends on how strong it was to start with. Whether or not this loss of strength means that the building in which it is used becomes unsafe in turn depends on the way in which the concrete was used and on the overall design of the building.

In this connection I must point out that most buildings are designed with ample safety margins which would take care of any loss of strength. It is important to make clear, and for it to be fully and widely understood, that the mere fact that a building contains high alumina cement concrete must not be taken to mean that it is necessarily for that reason dangerous.

After the collapse of the roof of the swimming bath at the Sir John Cass School in February last year we thought it right to ask local authorities to identify schools and other buildings with roofs of the same sort as the roof that collapsed at Stepney, and to have them appraised, particularly where there were likely to be high temperatures in the roof. At the same time the Building Research Establishment was asked urgently to look into the cause of the Stepney failure. Its report showed that the weakening of the concrete beams in the swimming pool roof was not solely attributable to loss of strength but was also the result of chemical attack on the highly converted concrete. Some serious weakening of the concrete was also found in the gymnasium roof where the conditions of temperature and humidity were less onerous than in the swimming pool.

It was at this stage that we concluded that high alumina cement concrete ought not to be used for structural work in building until further notice, and we put in hand the amendment of the building regulations so that local authorities could reject proposals for work involving the structural use of high alumina cement concrete. We advised local authorities that we considered it inappropriate in general that high alumina cement concrete should be approved for structural use.

We also decided that the appraisal and testing of buildings containing high alumina cement concrete should be extended to all buildings with precast prestressed non-composite roof or floor members, or columns, with spans of more than five metres. "Precast" means made separately and not cast in the course of putting up the building. Precast members are often made in factories rather than on site. "Prestressed" means that the concrete was poured around steel reinforcement held under tension. "Non-Composite" means that the member is entirely dependent on its own strength and is not embedded in other material which carries part of the load. And, while I am about it, five metres is equivalent to 16½ft.

Identifying these buildings has not been easy. We are grateful to the cement suppliers who gave us names of many of the precast concrete manufacturers and to the manufacturers who have given us lists of buildings for which they have supplied members. We are grateful, too, to designers and, not least, to the local authorities who have searched their own records and have passed on to private owners all the information that is being obtained from various sources. Of course, this information could not be as selective as we would have wished. Some of the buildings will have spans of less than five metres for which our advice has been, and still is, that appraisal need not, for the time being at any rate, be carried out.

At the same time that we started this detailed work on identifying buildings and notifying the owners, we asked the Building Research Establishment to carry out more research. This has taken longer than was at first expected, and, although we have been able to send out a summary of its main findings and the conclusions to be drawn from them in our most recent circular letter of 23rd April, its full report will not be published until later this month.

I should like to repeat what these conclusions are. First, our earlier conclusion that precast prestressed isolated roof beams represent the main potential hazard is confirmed, and all such beams, regardless of span, should be appraised by structural engineers. Second, the risk of structural failure in floors with spans up to about five metres is small and the Department's earlier advice, that appraisal need not be extended to these floors, still holds good at this stage. In the meantime, as the circular letter also explains, we have set up a special subcommittee of the Building Regulations Advisory Committee to provide further advice on the subject.

Its first task is to determine criteria which structural engineers can use for checking the designs of buildings containing high alumina cement concrete structural members. These checks, supplemented in appropriate cases by visual inspection, would identify those buildings in which safety margins are acceptable without further investigation, and those which require further investigation. Its second task is to determine what categories of buildings contai flings high alumina cement concrete structural members need not be appraised. This subcommittee has been asked to report before the end of July. The sub-committee meets weekly, has already had four meetings, and is holding its fifth meeting today.

It is right that we should put the size of the problem in perspective. Altogether about 22,650 buildings have so far been identified, of which 13,250 are housing, 1,450 educational buildings and 7,950 other buildings. Of these about 11,500 are in the public sector. The greatest estimate of the total number concerned is about 50,000—and, at the risk of repeating myself I must say that even if the total number is as great as this, there is no reason to suppose that more than a few of these will require remedial work. The number so far identified has been only 350.

One of the questions that has been asked more than once and has been asked again today is why was high alumina cement permitted to be used here when its use was prohibited abroad? The examples of Germany and France are often cited. It is true that in Germany the use of high alumina cement was prohibited following the collapse of farm buildings in Bavaria in 1961. But in those cases the cause of the collapse was corrosion of the reinforcing steel and the high alumina cement used in the concrete was of a different composition from that used here. In France I understand there has never been any prohibition on the use of high alumina cement concrete in private buildings. Its use in the public sector was prohibited in 1943 but since 1971 it has been allowed, although subject to strict conditions.

The hon. Member for Reading, North asked why high alumina cement concrete was permitted to be used after Professor Neville produced his paper in 1963. As an immediate consequence of that paper, the Institution of Structural Engineers set up a committee to review the whole field and to prepare a report for the guidance of engineers. The report of that committee, on which Professor Neville served, was published in August 1964, entitled "The Use of High Alumina Cement in Structural Engineering" and included the following paragraphs: Ample evidence exists to show that this cement can be used satisfactorily to produce sound and durable concrete when proper precautions are taken during mixing, placing and curing, and due regard is paid to the temperature and humidity conditions to which it may subsequently be submitted.… The stresses to be used for high alumina cement concrete are considered to be a matter for the Codes of Practice which deal with stresses and design criteria for structural concrete… High alumina cement concrete can be used safely for load-bearing members of a structure provided that certain precautions relating to its mixing, placing, and curing were taken.

Again, discussion of possible Government responsibility—when people talk about responsibility they usually mean financial responsibility—has centred around the fact that the codes of practice that are deemed to satisfy the mandatory requirements in the Building Regulations have, until recently, provided for the use of HAC. Let me make it clear that no one has been required to use high alumina cement concrete against his better judgment if he did not want to do so. Expert opinion at the time these codes of practice were prepared was that, provided high alumina cement was used properly— this is important—it was a safe and useful building material. The committees which prepared the codes of practice laid down strict conditions about its use and, had these conditions always been followed, there might have been no need for this debate. I can understand the feeling that Governments can sometimes be mistaken in accepting even expert advice, but I am also aware of what the reaction would be if Government were deliberately to disregard the best expert opinion.

Apart from the crucial question of safety, the issue that is concerning both local authorities and private owners is, of course, money. Who is going to pay for testing buildings and, if necessary, strengthening them?

For the public sector, as has been said. we have set up, at the request of the local authority associations, a working party which includes representatives of Government Departments, local authorities and health authorities. This working party is looking into both the practical and financial aspects of the problem. An exploratory meeting has already been held. Local authorities are particularly concerned about the money that would have to be spent on schools. The Government greatly appreciate the hard work which local education authorities have done, and the resourcefulness they have shown.

In continuing the education of pupils whose schools have been closed or partly closed, authorities have had some difficult decisions to take but they have rightly had the safety of the children as their first consideration at all times. They have carried out very extensive checks on their schools and as a result of this work the basic information on educational buildings is well documented. Officials are examining the information which is available about how much money will need to be spent, when it will need to be spent —and by which authorities—and are considering what further information is needed. Until all this has been done we cannot usefully take the question of the ultimate financial responsibility much further.

We have had letters, both through hon. Members and direct from the people concerned, about the worries and difficulties of owners of private flats who have been told that their flats contain high alumina cement concrete. I very much sympathise with them. It is not much comfort to be told to wait until yet a further committee has made a report at a later date to find out whether one's flat is safe, particularly if, in the meantime, one wants to sell it. But, as we said in our latest circular of 23rd April, the risk of structural failures in floors with spans of up to five metres is small. Where high alumina cement concrete is used in flats, it is usually in the floors, and in most cases, the floor span is less than five metres.

Most people who buy flats do so through building societies. I am told that the Building Societies Association is continuing its policy of advising its members to treat applications in respect of properties that contain or are suspected of containing high alumina cement concrete on their merits and to lend in the absence of serious deterioration, although they advise that special care should be taken in the case of completed flats. Where flats are in the course of construction, the BSA is advising societies to defer lending by way of building finance until the borrower can produce a certificate of structural soundness. A number of building societies are known to be granting mortgages on houses and flats contain- ing HAC concrete. I must, however, emphasise that this is a matter for the individual building societies themselves. They are not obliged to follow advice given by the Building Societies Association, nor, of course, can we tell them what to do.

I should like to assure the House and the public that we are far from complacent about this problem. We recognise the serious concern it has aroused, and the practical and financial problems it has posed for innocent individuals, let alone for public authorities. But the opposite of complacency should be neither panic nor sensationalism but thoughtful rational action, directed first to a solution of the immediate problem and then examination of the action necessary to prevent similar situations arising. Although we have still to complete the first stage—

The Question having been proposed after Four o'clock and the debate having continued for half an hour, Mr. DEPUTY SPEAKER adjourned the House without Question put, pursuant to the Standing Order

Adjourned at twenty-eight minutes to Five o'clock