He will travel from Victoria in a few weeks to visit the school for the first time since the late 1970s, to "say my farewells" to his best friend Andrew Nash, who took his own life in 1974, aged 13.

"I don't need to be there with a crowd when I do that," Mr Dunn said.

"I know when I get there it's going to be emotional. I haven't been back to the place since I left. That's going to be hard enough on its own."

Mr Dunn was sexually abused by former Marist Brother Romuald, real name Francis Cable, and was in court in 2015 when Cable was sentenced to 16 years jail for crimes against 19 former students.

In 2016 the Marist Brothers linked Andrew Nash's death with sexual abuse.

"I want to acknowledge today in public that I accept on behalf of the Marist Brothers that all the evidence points to Andrew having been sexually abused," Australian Provincial Brother Peter Carroll told the Royal Commission into Institutional Responses to Child Sexual Abuse.

Andrew Nash's mother Audrey Nash, who will be at the memorial dedication, told the royal commission she believed Andrew was sexually abused by Francis Cable, who was one of her son's teachers.

John Dunn remembers the day in 2nd form when his class sat down to watch a documentary on Alvin Toffler's Future Shock.

"I'd saved a seat for my best friend who failed to arrive," Mr Dunn said.

"At the end of the video our class master and social studies teacher informed us the empty chair next to me would be forever vacant."

Mr Dunn was an altar server for Andrew Nash's funeral at Sacred Heart Cathedral.

"It was the first time I had encountered and understood what death really meant," Mr Dunn said.

He will not be at the memorial but Clergy Abused Network founder and Marist abuse survivor Bob O'Toole will read parts of a eulogy written by Mr Dunn for his friend.

"I buried my friend, but I have never said goodbye," Mr Dunn said.

The memorial dedication led by Mr O'Toole, Mrs Nash, Maitland-Newcastle Bishop Bill Wright and members of the Marist order will start at 6pm on Catholic Church land at the corner of Parkway Avenue and Everton Street.

Mr O'Toole, who raised the need for a memorial after strong criticism of the Marist order by the royal commission following devastating evidence at a Newcastle public hearing, said it was a place for people to reflect.