Close shave for home owner as glass door shatters suddenly
Expert explains why tempered glass doors can do this from time to time and suggests safer alternatives
A mere four seconds was the difference between Mr Sito Rong Feng walking unscathed into his kitchen and being hit by a sliding glass door as it shattered into smithereens.
When the wedding photographer had the close shave last month, his first thought was the safety of his 15-month-old twin sons who were playing in a playpen in the living room of the family's Punggol East flat.
He found pieces of the tempered glass in the playpen, but his boys were unhurt.
Glass was scattered across the living room, and Mr Sito, 38, and his wife, Ms Eldora Lie, 33, sustained minor cuts on their feet.
"If I had walked slower, I would've got injured. Worse, if my boys had been sitting on their high chairs at the dining table, they could have been seriously hurt when the glass fell," he told The New Paper yesterday.
"My wife also does work at the dining table all the time. So I guess you can say it was good timing that this happened when no one was there."
Footage from a closed-circuit television camera shows the door exploding with a loud sound and crashing onto the floor about four seconds after Mr Sito walked into the kitchen.
Mr Sito said before they moved into their new home in May 2018, they decided to put in a sliding door to keep the smell of cooking within the kitchen and the air-conditioning within the living room.
He was baffled why the tempered glass door would spontaneously shatter when no one was touching it, and added that it took four people - the couple and two handymen - more than two hours to clear the mess.
The impact was so huge that some glass shards were embedded in the vinyl floor.
Mr Sito, who has yet to decide whether to replace the door, said he is discussing it with In2Space Interior, the firm that installed the original door.
"All I know is that we won't be getting a tempered glass door ever again," he added.
When TNP contacted In2Space Interior, its managing director, Mr Henry Yeo, 54, said he was checking with the door supplier to determine the cause of the sudden explosion.
"While such incidents are rare, it does happen. We do advise customers that glass is a breakable material, so they must be careful," added Mr Yeo, who offered to replace Mr Sito's door, which is no longer under warranty, at cost price.
Another home owner, whose tempered glass partition in her study room suddenly shattered in May last year, said she could not get her contractor to assess the damage as it happened during the circuit breaker period.
The housewife who wanted to be known only as Ms R. Lim, 40, and lives with her husband and three children in a terrace house in Serangoon, said she decided to do without a new partition in the end.
An industry expert, Mr Victor Sia, 32, who works as a research and development engineer at SG Glass, told TNP that tempered glass often contains impurities such as nickel sulphite, which can cause microfractures in the glass during the heating process.
Tempered glass is known to be four times stronger than untreated glass as it gets strengthened through heat.
But after heating, the surface cools down faster than the inner sections of the tempered glass. This can create tension within the glass and lead to high internal compressive stress, which could explain the sudden explosions, he added.
Mr Sia said such incidents occur from time to time, and home owners could opt for laminated glass instead of tempered glass.
"Laminated glass is safer because even if it shatters, the glass shards will remain in place instead of flying everywhere. It is just not as aesthetically pleasing as tempered glass and costs twice the price," he added.
Customers could also opt for wooden or aluminium sliding doors, which are common alternatives to glass.
A check with the Consumers Association of Singapore (Case) revealed that it received 14 complaints of furniture and household products spontaneously shattering from 2016 to last year.
There were two cases each in 2016 and 2017 and one each in 2018 and 2019. The number shot up to eight last year.
Of the eight cases, four involved glass hobs and two involved glass panels.
Safety tips for home owners include not overheating or placing heavy objects on glass surfaces, said a Case spokesman.
Upon installation of a glass panel or door, home owners should also inspect the glass for any scratches or cracks.