The scaffolder, who obtained his licence and training in NSW and was working under reciprocal arrangements in the ACT, has been severely reprimanded by the safety regulator after a scaffold he erected at a residential building site in Crace collapsed and an apprentice carpenter narrowly avoided a three metre fall.

According to the WorkSafe report on the accident which took place in July, the carpenter "stepped on metal plank three metres above the ground in order to access a ladder, the plank, tied with wire onto a piece of wood, dislodged and fell to the ground. The worker's leg fell through the scaffold and the worker fell forward, grabbing another part of the scaffold to avoid falling to the ground. He sustained a number of injuries to his back, thigh and shoulders."

ACT Work Safety Commission Mark McCabe said falls from height were the leading cause of death in construction. Queanbeyan construction worker Nik Spasovski was killed in 2006 when he fell through an unmarked hole during the construction of the Australian Tax Office in Civic and 23-year-old Jayson Bush was lucky to escape with his life when he fell more than six metres down an air conditioning shaft at the Nishi site in Civic last year – sustaining a raft of serious injuries including a broken back.

Mr McCabe warned that people who hold a high risk work licence under Work Health and Safety legislation "must have and maintain the competencies the licence indicates they hold" and would have their licences suspended if they breached safe work practices.

Mr McCabe said inspectors had seen numerous examples of unsafe scaffolding, including wire, rope and ties being used to hold scaffolding together.

When the fall was reported to the regulator in July, Mr McCabe said inspectors had been "aghast" to see the state of the scaffolding at the building site.

An independent scaffolding expert was also called to do an inspection and confirmed there were numerous issues.

Legislation allowed WorkSafe to suspend the man's licence immediately for a period of 28 days – but Mr McCabe said it became "apparent that the man should not be responsible for further scaffolding work as we had some clear reservations about how he was approaching the task."

"So we took the decision to suspend his licence until he can be retrained and get a new statement of competence."

Mr McCabe said he had not suspended a scaffolding licence before.

"This has severe financial implications as we are taking away someone's livelihood for a year and we don't do that lightly."

He appealed to construction workers to report unsafe practices, saying this situation had only come to light when inspectors were called in after a near accident.

The regulator has the option of cancelling high risk work licences altogether .

"Licensing is one of the important ways that risks of certain high risk work are mitigated. To obtain a high risk work licence, a person must demonstrate competence through training and experience," Mr McCabe said

"If people are concerned about the competence of a high risk work licence-holder they should contact WorkSafe ACT so it can investigate and respond appropriately," he said.