So claims David Mahaffey, technical officer with the Australian Concrete Repair Association, after visiting the site of the home unit balcony collapse reported in February 19's Manly Daily and being surprised to see someone standing on a balcony just next to the one that fell off under its own weight.

The incident has added even more urgency to ACRA's plans to press for mandatory periodic inspections of older buildings by a qualified person. This is particularly so given that Mahaffey's examination of the failure has revealed the likelihood of collapse of any one of the sister balconies on the same home unit block.

"Our inspection confirms that the main cause of the failure was the corrosion of the steel reinforcement in the concrete," says Mahaffey.

"This corrosion caused the steel to be eaten away to the point where it was no longer able to carry the load of the balcony, even without anyone standing on it.

"Even more concerning, however, is that the lower balcony that was wiped off in the collapse shows virtually the same level of corrosion as the balcony that fell. It was clearly just a matter of time before that balcony also fell under its own weight. And the same can be said for any of the other balconies on the building. Clearly, there is a very real danger of death or injury if anyone uses these balconies."

Which explains ACRA's concern at Mahaffey's report of a resident standing on one when he visited the site a week after the collapse.

"ACRA isn't privy to the level of investigation undertaken into this failure, but the very first step that should have been taken in our opinion was to seal off all points of access to the other balconies on the building," says Mahaffey.

"There is also clear evidence that the building has undergone some rectification work in the recent past, including repair of concrete spalling due to reinforcement corrosion. Despite this, the balcony has been left in a state where collapse is a very real threat.

"This is an alarming example of a major problem in the concrete repair industry: Minor damage that is highly visible gets the most attention while life-threatening structural faults remain untreated, usually because the chosen contractors are unqualified to diagnose structural problems.

"As ACRA has been saying for years, balcony collapses are inevitable in such cases unless skilled professionals, with expertise in concrete repair, are asked to investigate the condition of the structure before repair work starts even on so-called 'minor' problems."

Note: Please click here to learn more about MJ Civil Engineering's recent work with defective concrete balconies.