SHOWER ROOM TEMPERED GLASS DOORS IN HDB FLATS (Shattering)

Miss Penny Low asked the Minister for National Development as the shattering of shower room tempered glass doors has been classified as "rough handling and improper renovation works" (a) what are HDB's criteria for determining rough usage as research shows that a very high force or stress is required to cause tempered glass to shatter; and (b) as there were two cases where the shattering has resulted in shards rather than fragments, what is the quality control process that HDB uses to ensure the safety of the homeowners.

The Senior Parliamentary Secretary to the Minister for National Development (Assoc. Prof. Koo Tsai Kee) (for the Minister for National Development): Mr Speaker, Sir, HDB uses tempered glass for its shower screens as it is stronger compared to normal glass, and tempered glass is less likely to cause injury when broken. While tempered glass is able to withstand stronger impact than normal glass, it can still break, if used improperly. Rough usage may cause chipping of the glass. Over time, the chips may develop into cracks, causing the glass to break suddenly when they widen to a certain crack width.

It is difficult to pinpoint the actual cause of the breakage after the incident. Nevertheless, in some instances, there are signs that would indicate the possibility of rough usage. These include:

1. Cracks on the brackets holding the frameless glass door, which may be caused by repeated slamming of the glass door;

2. Dislodgement of the frame holding the fixed glass panel from the outer frame;

3. Chips at the glass edge on the unbroken glass; and

4. Scattering of glass fragments over a big area.

Sir, the shower screens are installed using specialised systems, according to the prevailing industry standard. The glass suppliers supplying tempered glass to HDB projects have their in-house quality control testing to ensure that the tempered glass meets the required standard. Since mid-2002, HDB also conducts additional sample testing to ensure the quality of the tempered glass.

Dr Teo Ho Pin (Holland-Bukit Panjang): Mr Speaker, Sir, may I ask the Senior Parliamentary Secretary whether the HDB has a code of practice on the use of tempered glass and whether it is suitable to use tempered glass in our public housing estates, especially in those public areas?

Assoc. Prof. Koo Tsai Kee: Sir, there is a standard for the use of glass in Singapore and that standard is called Singapore Standard 341 (SS341). The latest standard is SS341-2001. I have a copy here, and the standard specifies the kind of glass that can be used.

Is tempered glass a suitable glass for use in HDB homes? Sir, tempered glass is a standard building material. It is used in offices, hotels, in Parliament here, and it is therefore suitable to be used in HDB flats.

Miss Penny Low: In one of the past sittings in this House when the shattered shower glass screen issue was brought up, I was given the assurance that all units with tempered shower screens would be checked. I understand also that indeed the HDB officers had gone around to do the checking. Nevertheless, a number of units that experienced shattering shower screens recently were inspected units. Not only that, they resulted in shards rather than rounded-edge pieces of shattered glass. That indicates certain defects within the material itself. In other words, it is not due to rough usage but to a defective product. May I ask what is the explanation for that, since they were already checked, they were inspected to be good and not defective, and yet they cracked into shards, and that is defective?

Assoc. Prof. Koo Tsai Kee: Sir, following the Parliament session last year when I replied to Miss Penny Low, HDB went to about 15,000 flats and inspected almost 30,000 shower screens. The purpose of that exercise was to inspect for the quality of the hinges and the fixtures that were used to hold the frameless tempered glass screens. At the same time, during the inspection, HDB officers also inspected for any chips resulting from rough usage. At that exercise, some glass panels were changed because they found that some of the hinges were not in order and we suspected that these hinges came loose because of rough usage. So, we made good all the glass shower screens we thought at that time were not in order.

These two accidents came about after the inspection. The inspection process does not guarantee that future accidents would not occur. But it did guarantee at that time that the inspected batch was safe for use.

Dr Teo Ho Pin: Sir, may I ask the Senior Parliamentary Secretary how does the Ministry define rough usage in HDB's context, and whether SS341 defines rough usage?

Assoc. Prof. Koo Tsai Kee: Sir, SS341 defines three methods for testing the safety of tempered glass. SS341 specifies that the glass should go through three tests. The first one is called the impact test, ie, you break the glass upon a certain impact. The second test is known as the fragmentation test. It is to pierce the glass to see how many pieces it breaks into over a small area. The third test is the surface compression test which sends a light ray through the glass and measures the angle of bending of the glass.

Rough usage, unfortunately, is quite common in many of the instances that we have inspected. In fact, in the incident in Block 130 Edgedale Plains, HDB suspected that the glass broke because of rough usage. But, having said that, once a shower screen has broken into pieces, it is difficult to ascertain whether it is truly rough usage or any other cause. But based on the inspection on a sample size of about 30,000 shower screens last year, we have come to the conclusion that rough usage is the principal cause of many of the accidents that have happened in the HDB flats.

Mr Low Thia Khiang (Hougang): Sir, I wonder whether it is cost effective and necessary for the HDB to install such shower screens in completed HDB flats. I think the owner can easily get a contractor to install whatever he wants.

Assoc. Prof. Koo Tsai Kee: Sir, the use of tempered glass is a common practice in the private sector, whether it is in the office or in the homes of the private estates. Therefore, HDB was just following standard practice.

Yes, we have learnt from this episode and we will have to decide whether we will continue the use of glass shower screens in future HDB contracts.

Miss Penny Low: Could the Senior Parliamentary Secretary then explain what instances would cause tempered shower screens to shatter into shards rather than in rounded pieces? Because, if the incident at Block 130 Edgedale Plains was caused by rough usage, then it should not have shattered into shards.

Assoc. Prof. Koo Tsai Kee: In the incident mentioned by Miss Penny Low, we suspected that rough usage was the cause of the shattering. The fact that the shower screen shattered into shards rather than into small little pieces is something that HDB has to do further tests on. So, we will subject some of the glass shower screens in the cluster of flats around Block 130 to the surface compression test, which is a non-destructive testing which can be done in-situ. We are willing to go to every unit in the Block 130 cluster. We will instruct HDB to work with Miss Penny Low and her grassroots leaders on the possible replacement of some of these shower screens, if Miss Penny Low thinks that they should be replaced.

Dr Tan Boon Wan (Ang Mo Kio): Sir, I would like to ask the Senior Parliamentary Secretary whether there is a possibility that tempered glass can shatter in shards and not necessarily in rounded pieces.

Assoc. Prof. Koo Tsai Kee: Sir, tempered glass can break and, when they break, they break into small little pieces. When they break into shards, we have to subject the glass panel to further tests to see why they break into shards rather than into small little pieces.

Miss Penny Low: I am happy to hear the Senior Parliamentary Secretary assuring us that they would look into the shattered shower screens together with my residents and grassroots leaders. Can I propose that we form a special task force to jointly look into this issue as well as other estate developmental issues because there have been some unhappiness and inconveniences brought to the residents due to the slowdown in the building project in Punggol 21?

Assoc. Prof. Koo Tsai Kee: Mr Speaker, Sir, yes, we would ask HDB to work with the MP of that area to look into all the issues in the estate, including the issue of broken shower screens.