HOUSING AND DEVELOPMENT BOARD FLATS (Repair of spalling concrete)

Mdm Cynthia Phua asked the Minister for National Development whether he will consider helping the HDB lessees repair the spalling concrete in their flats.

The Senior Parliamentary Secretary to the Minister for National Development (Assoc. Prof. Koo Tsai Kee) (for the Minister for National Development): Mr Speaker, Sir, spalling concrete is the result of a natural deterioration process called carbonation. When the surface concrete is carbonated, corrosion of the steel bars within the slab sets in. The corroded steel expands, thus causing the concrete surrounding the steel bars to crack. This problem may affect flat owners as their flats become older.

Under the Lease agreement, HDB flat owners are responsible for the repair of spalling concrete in their flats. HDB flat owners who encounter spalling concrete problems in their flats can, however, report them to their respective HDB Branch Offices. HDB can assist the flat owners to investigate the problem and recommend appropriate remedial action. For flat owners who have difficulties in finding a suitable repair contractor on their own, HDB can also assist to provide them with a list of repair contractors, whom they can negotiate with on a strictly private basis.

Dr Teo Ho Pin (Holland-Bukit Panjang): Sir, may I ask the Senior Parliamentary Secretary, when does HDB expect a new flat to have spalling concrete problem? Can he give us the number of years?

Assoc. Prof. Koo Tsai Kee: Sir, there is what we know as a defect liability period. For new flats selected by the buyers within a year, the HDB will be obliged to ask the contractor to come back to repair any defects. So, if the flat is within the one-year old period, then the spalling concrete, if it occurs, would be a workmanship problem.

Mdm Cynthia Phua (Aljunied): I would like a clarification from the Senior Parliamentary Secretary. Currently, for flats that are above 20 years old, ie, those built in the early 1980s, there are about 450,000 flats, and there was a scheme of three years, and only about 2%, ie, 17,000 flats were given assistance. In 1987, there was a change in the quality of concrete, from 20 to 30. And because of that, we notice that there is a difference in the degree of spalling concrete in the newer flats, but not in the older flats. So, I would like to appeal to the Ministry to consider helping those flats that are above 20 years old in the IUP or the MUP.

Assoc. Prof. Koo Tsai Kee: Mr Speaker, Sir, first of all, under the MUP programme, HDB repairs spalling concrete defects on a goodwill basis, for the simple reason that these flats would be very old. In order to qualify for MUP, the flats would be way above 10 years old. Spalling concrete is a problem of an aging process. Flats need maintenance. As flats age, problems set in. So spalling concrete is a maintenance problem. It is not a design or workmanship problem. New flats have fewer problems. That is the reason why the Member pointed out that flats built after 1990s, for example, have fewer problems because they are young. When we are young, we have no problems. We have no arthritis, or rheumatism. As we grow older, problems set in. So we will see a specialist or a doctor. It is not true that flats built in the early 80s have a high incidence of spalling concrete. They have high incidence because they are older. You ask any doctor, he will say that older patients have more problems.

HDB conducted two goodwill repairs over two periods. In 1988, HDB conducted a goodwill repair, and repaired flats with spalling concrete defects. 75,000 households benefited from that goodwill repair and it cost the Government $30 million - big money in those days. Then in 1995 to 1998, HDB conducted another goodwill repair scheme for something like 27,000 households. So with these two goodwill repair schemes completed, HDB feels that there are very few spalling concrete defects left in the flats. Those that come on-stream now would be taken care of during the MUP programme.

Dr Teo Ho Pin: May I ask the Senior Parliamentary Secretary, based on natural deterioration of concrete, which he mentioned as carbonation, how many years does he think a new flat built by HDB will have a spalling concrete problem? My understanding is that concrete, if properly constructed, can last 60 years. Maybe he can let us know how long it can last.

Assoc. Prof. Koo Tsai Kee: Mr Speaker, Sir, concrete, if well maintained, can last for a long time, longer than 60 years. But during the durability period, there will be minor repairs here and there. The spalling concrete needs routine maintenance, which we need to cater for flats which are way above 10 years old. So in our environment which is high in moisture, and in certain places which is high in carbon dioxide, carbonation takes place faster. For example, in the kitchen area which is heavily used for cooking, then we will find that spalling concrete may occur faster than in the living room.

Mdm Cynthia Phua: Mr Speaker, Sir, I would like the Senior Parliamentary Secretary to give us some statistics to show that spalling concrete only happens in the older flats and not the newer flats, especially in 1987, when there was a change in the grade of concrete.

Assoc. Prof. Koo Tsai Kee: Mr Speaker, Sir, we have done some studies on the correlation between the age of a building and the instances of spalling concrete defects per thousand flats. For flats built before 1983, flats which are about 18 years old, the number of spalling concrete defects is 39.3 per thousand households. For flats built between 1983-1986, the number of defects is 25.9 per thousand households. For flats built between 1987-1990, the number of defects is very low, ie, 1.8 per thousand households because they are very young. And for very new flats built between 1991-2002, the defects of course is miniscule, 1.5 incidents per thousand households. So Members can see that the correlation is very simple. When the flats are young, there are few problems. When they are old, there are lots of problems.

Dr Teo Ho Pin: May I clarify with the Senior Parliamentary Secretary? He said that after 10 years, we can expect spalling concrete. Am I correct in saying that?

Assoc. Prof. Koo Tsai Kee: If it is not maintained.

Dr Teo Ho Pin: All HDB flats are properly maintained by the town councils. May I say to the Senior Parliamentary Secretary that it is not true that it is just a maintenance problem. It is the design, construction and maintenance that will affect the durability of the concrete structure. So, the design and construction are important. We have many new flats built in the 1990s using grade concrete, and yet we have spalling concrete problems. Does it mean that the HDB is going to repair all these spalling concrete problems for flats built in the 90s?

Assoc. Prof. Koo Tsai Kee: For these cases, perhaps the Member would like to highlight to the Ministry. Basically, spalling concrete happens within the flat, and it is outside the purview of the town council. I am sure all town councils in Singapore maintain their common property very well. The spalling concrete is an internal matter. It is between the flat owner and his property. A simple maintenance like repainting, for example, will prevent carbon dioxide from penetrating the outer layer of the concrete, thereby corroding the steel bars. As I said, if the flat is within one year old, we are obliged to repair. If it is outside one year, we will take a look, but the flat owner must repair. Spalling concrete is a slow process. It is easily detected. It is inexpensively repaired. One can do it himself if the repair area is small, meaning 1.5 square metres. If it is larger, he can always contact a contractor. HDB has, through the two goodwill programmes, trained hundreds of contractors who are competent in repairing the spalling concrete. And the cost is very cheap, ranging from $50 to a few hundred dollars.

Mr Low Thia Khiang: Mr Speaker, Sir, I wonder whether the Senior Parliamentary Secretary has statistical data on spalling concrete, so as to compare the older Tiong Bahru estate at Seng Poh Road area, built before the HDB, with flats that were built in the 80s. And does he honestly believe that the grade of concrete that was used in the construction, and also the workmanship in which the steel bars were placed at the correct interval, are important factors that will decide whether or not there is spalling concrete? He also said that when one gets old, he is more prone to sickness and he compared it to spalling concrete. Does he also agree that if a person is born with a wrong genetic heritage, he may not live that old but can get sick very fast?

Assoc. Prof. Koo Tsai Kee: Sir, I think I am qualified to speak about the conditions of flats in Tiong Bahru, being the MP for the last 10 years. Spalling concrete does occur in Tiong Bahru flats, like all flats. In all concrete buildings, spalling concrete will occur. It is a matter of when. If the flat is maintained well, spalling concrete appears much later down the road. The design of the flat, as well as the grade of concrete, does affect the occurrence of spalling concrete. At any one time, HDB flats are designed according to the latest building codes. So there is no question of cutting corners in the construction of the HDB flats.

Mdm Cynthia Phua: The Senior Parliamentary Secretary stated that it is the owner's responsibility to maintain and repair spalling concrete. But spalling concrete always happens at the slab that is between two flat units. And the leakage of the moisture is always from the upper unit going down to the slab and into the lower unit itself. In such a case, it is difficult for the owner of the lower flat to maintain that slab that is affecting the owner below. So would the Ministry consider helping the owner in the repair of spalling concrete? I would like to appeal to the Ministry to seriously look into this under the IUP.

Assoc. Prof. Koo Tsai Kee: Mr Speaker, Sir, if the spalling concrete is a symptom of a ceiling leak between the upper and the lower households, then the HDB will take a look at it and give advice accordingly. If it is a case of pure spalling concrete, then it is simple to repair, because the owner has absolute control over his ceiling. He does not need to interfere with the neighbour upstairs. If it is a case of a ceiling leakage, ie, water seeping through the toilet, then it needs the cooperation of two parties - the upper floor neighbour and the lower floor neighbour. The law is quite clear that both parties must share the responsibility. Sometimes, both parties cannot come to an agreement, either because of the timing or the nature of the repair, in which case HDB will step in and be the expert counsel.

Mr Inderjit Singh (Ang Mo Kio): Sir, the Senior Parliamentary Secretary has put the blame of maintenance on the real cost of spalling concrete. I would like to explain to my residents what does maintenance mean and what it takes to maintain. So, can the Senior Parliamentary Secretary make available a list to the public on the maintenance that is necessary and, if they do the maintenance, how many more years they would earn before spalling concrete sets in?

Assoc. Prof. Koo Tsai Kee: The simplest form of maintenance is to repaint the ceiling of the flat, as and when is required. If we use good water-proof paint, for example, then it should last between 5-7 years. Some paints are moisture resistant. So, by painting the ceiling of the flat, it will prevent carbon dioxide from penetrating the surface of the concrete. The carbon dioxide reacts with the alkaline on the steel bars and therefore reduces the rust-proof nature of the steel bars. So Members should advise the flat dwellers to paint their flats.

Mr Tan Soo Khoon (East Coast): Sir, I take exception to the Senior Parliamentary Secretary's reply that the problem of spalling concrete is not due to poor workmanship. Is he not aware that poor workmanship has, in fact, been stated as the cause of spalling concrete problem in this House, maybe not by his present Minister but by previous Ministers in the House? Why is it that residents are made to pay for repair to a problem which is, in fact, inherent? Is he not aware that in my constituency, and in many other constituencies, this problem has been evident since the day the flats were completed, and this is particularly true in my constituency when the flats were built in the 1980s? So, is it not time that HDB dealt with the problem, instead of now just telling the people to paint their ceilings?

Assoc. Prof. Koo Tsai Kee: Mr Speaker, Sir, I mentioned earlier on that the Government carried out two goodwill programmes, one in 1988 and another in 1995-1998. With these two programmes, the flats in Bedok, for example, would have been completely taken care of. If any spalling concrete did occur because of workmanship, I do not agree.

Mr Arthur Fong (West Coast): Sir, Mdm Phua mentioned about the goodwill repairs during the IUP. I have flats which have gone through the IUP and they have the accelerated programme. After the IUP, the spalling concrete persists. Maybe the HDB can consider the goodwill repairs to start for these flats.

Assoc. Prof. Koo Tsai Kee: I believe that if spalling concrete did occur after IUP, it could be a case of ceiling leakage, in which case, the Member could advise his residents to appeal to him, and he could then write in to the Ministry. It could be a case of ceiling leakage. The early stage of spalling concrete makes it difficult for contractors to decide whether it is pure spalling concrete or a case of ceiling leakage. But in any case, as I said earlier on, during the MUP period, we will do a major goodwill repair. After IUP, there is MUP.

Dr Teo Ho Pin: Sir, may I ask the Senior Parliamentary Secretary whether it is the HDB's responsibility to design flats according to the respective uses in the flat? If it is the kitchen, and we know there are cooking activities, we have to design a ceiling that can withstand the smoke and oil, and it should last. But spalling concrete occurs in bedrooms also. So, how do we maintain the ceilings of bedrooms?

Assoc. Prof. Koo Tsai Kee: Mr Speaker, Sir, I do not know about spalling concrete in the bedrooms. For spalling concrete to occur, basically, carbon dioxide, moisture and oxygen need to penetrate the surface layer. I am sure these are exceptional cases. We will be interested to take a look at them.

Mdm Cynthia Phua: Sir, I am utterly confused.

Mr Speaker: Mdm Phua, let the Minister reply first.

Mdm Cynthia Phua: All right. I am sorry.

Mr Mah Bow Tan: Mr Speaker, Sir, there are two issues here. The first issue is: what is the cause of the spalling concrete? If the cause of the spalling concrete is due to the design, as some Members allege, and it can be proven as such, then obviously it is HDB's responsibility to fix it, either in the flat that is currently affected by spalling concrete or to fix it in future designs. But if it is a matter of deterioration - natural wear and tear - then, obviously, the responsibility lies with the owner.

Sir, if any Member of the House here feels that flats in his constituency or estate are affected by spalling concrete due to design or poor workmanship problems, then, by all means, please take it up with the Ministry and, if we can establish the cause, we will take the necessary measures. There is no point in trying to lump the two issues into one because, obviously, there is a limit to the kind of maintenance that HDB can carry out in the flats. HDB flats are 10, 15, 20, 30 years old. Wear and tear takes place, and some of the repairs and maintenance must be undertaken by the owners themselves. This is perfectly normal. If the wear and tear takes place after 10-15 years, to expect the HDB to undertake repairs is obviously not fair.

Having said all that, of course, we spend a considerable amount of money going back to the flats for interim upgrading, main upgrading, goodwill repairs and so on and so forth. So, I do not think it is fair for Members to suggest that HDB, after selling the flats to our residents, just walks away and forgets about it. In fact, on the contrary, our after sales service is probably far superior to any private sector developer. Members can ask a private sector developer - whether it is City Developments, Far East Organisation or whoever - after five years of living in your flat and something goes wrong, ask them to come back and look at your flat, I think Members here will know what the answer is.

Mr Speaker: Mdm Phua, do you want to ask your question?

Mdm Cynthia Phua: Sir, the Minister has clarified. I would like to thank the Minister for agreeing to handle the exceptions.

Ms Braema Mathiaparanam (Nominated Member): Mr Speaker, Sir, may I make a suggestion, or maybe it is already being done at the HDB? Perhaps, some best practices ---

Mr Speaker: Ms Braema, you can only ask a supplementary question. You cannot make suggestions.

Ms Braema Mathiaparanam: Or I can turn it ---

Mr Speaker: Let us try.

Ms Braema Mathiaparanam: Sir, where private high-rise buildings are concerned, I would like to know, for the same time span, what is the number of spalling concrete defects as compared to those in HDB flats. Perhaps from here there are some learning points.

Assoc. Prof. Koo Tsai Kee: Mr Speaker, Sir, obviously, we do not compile statistics of private dwellings, but we do receive feedback from buyers of private condominiums that they suffer the same problems. But these problems are not highlighted in the public domain like HDB flat defects are. Having said that, the Building and Construction Authority (BCA) does what we call a CONQUAS survey. CONQUAS is the acronym for Construction Quality Assessment System. We found that the quality of HDB flats is the same as the quality of private condominiums, by and large. And, as the Minister has rightly pointed out, HDB does a lot of goodwill repairs. They do a lot of follow-up. They give expert consultations. They try to rope in contractors to repair and, sometimes, they even bargain on behalf of the consumers to get a low price from the contractor.