OUT-OF-HOURS school learning cannot succeed simply on the goodwill of teachers, delegates at a major conference were told.
There were also fears that too many children are missing out on after-school clubs and activities. Chris Jones, Cardiff council's chief schools and lifelong learning officer, said a lack of qualified staff could be limiting opportunities.
Speaking at the conference, held by community learning charity continYou Cymru last week, he called for more training opportunities and continuing professional development.
"We've moved on from the days where you could say Mr Thomas likes kids - he'll do that," Mr Jones told delegates.
"We need people with a proper job description to manage things."
In 2005, ContinYou Cymru, along with the Association of Directors of Education in Wales, said every school should be offering out-of-hours activities for pupils and the wider community by 2010.
However, so far it has been described as a "bit of a postcode lottery", with some local authorities more active than others.
Pam Boyd, director of ContinYou Cymru, called for anyone already involved in out-of-hours learning to sign up to a pledge at the conference, to demonstrate their commitment.
"There are still some children who are missing out," she said. "We want to ensure everyone has access to these opportunities."
Mr Jones said taking part in extra-curricular activities helped children to develop into good citizens.
He said latest figures in the capital city showed 20,000 children were already involved in after-school activities such as football clubs, poetry jams and singing groups.
But he also said it was important to consult the community to make sure the right plans and policies were in place.
"There's been a decade of progress in Cardiff, where central funding is passed down to schools, but much work still needs to be done in this area."
He described as "scandalous" the under-use of school buildings "packed to the rafters with expensive resources".
But he added: "It's not always easy to persuade the council or schools that out-of-hours learning is the best way of investing money. To be considered of real value, it must become subject to monitoring and evaluation."
The conference was the latest in a series held by ContinYou Cymru to promote community-focused schools. Guidelines drawn up last year advise an urgent review of safety and protection policies.
Assembly government guidance (Community Focused Schools: Making It Happen) also warns schools that over-18s who may attend classes with children are not required to have criminal bureau checks.
But Jane Davidson, minister for education, lifelong learning and skills, has also said that education would be available from the cradle to the grave with the emergence of the CFS philosophy.
RURAL LOSE OUT
Welsh-speaking children, especially in remote rural areas, are at a disadvantage when it came to out-of-hours learning, according to Sian Eirian, director of the Eisteddfod and Urdd Gobaith Cymru, the Welsh-medium youth movement.
The festival leader said the annual Eisteddfod, which attracted 14,000 pupil entrants last year, was an extra-curricular success.
"It leaves something very rich behind - children know they're working to the highest standards," she told delegates But Ms Eirian said she was concerned at the extra cost and burden to parents of children in remote, Welsh-medium schools, many of whom could not get a bus home.
Her views echoed those of Pam Boyd, ContinYou Cymru executive director, who said last year that she was concerned small schools in rural areas had been slower in getting off the mark because of transport problems.