Nick Cobb gestures around the playground of Ivydale school. “When my children started here,” he says, “I hadn’t been into a school since I left one. I thought, ‘Oh dear, this place needs brightening up.’ ” Ivydale School, a handsome late-Victorian building with an asphalt playground set in a quiet residential area of Peckham, south London, was a school with problems. Over the past few years, it has turned itself around and has just had a “very positive” inspection from the Office for Standards in Education.

One factor that has helped to boost the morale of the school community has been the involvement of Nick Cobb, first as parent, then as member of the Friends of Ivydale, then as parent-governor. His story is typical of the unsung work of many parents who contribute to the improvement of their children’s schools.

Mr Cobb is an artist. He and his wife have two children: Liam, aged eight, and Theo, four. He trained at St Martin’s and Wimbledon and has shown his work at such venues as the Whitechapel Gallery, and the Open Studio at Camberwell. He describes himself as “struggling”.

When he discovered that the school in which his son had enrolled could also be described as “struggling”, his first thoughts turned to the visual environment.

“There was,” he recalls, “talk of a mural.” As it turned out, the brickwork in the playground was too damp for a mural but Mr Cobb’s expertise told him that in many ways plywood would be better: it would be easier to work on, and could be detached and cut to size. Best of all, he had a lot of offcuts in his studio.

It was hard to get anything going in the school, but the reception class, which was reading the Funnybones books at the time, expressed an interest in helping out with the mural.

Mr Cobb brought in some paraphernalia associated with the Mexican Day of the Dead and got the children drawing and painting, sticking and cutting. Then he copied the full-size collages on to the circles of plywood and varnished them. There they stand, on one of the walls of the shelter in the playground, vibrant with enthusiasm.

“I was beginning to see how you could fit in with the national curriculum, ” says Mr Cobb. “It was left to me, so I worked my way through the infants and just fitted in with the themes they were doing in class. When a teacher was interested and had time, I worked with that class.”

Work often began with making lists. “I always like to help them find what they want to do,” says Mr Cobb.

Often, he would bring in objects for observational drawing - a starfish, for instance, when the class was studying the seaside. Themes over the next couple of terms included the seasons and life in forests. Sometimes, the themes crossed year boundaries.

At one time the reception class was working on materials and clothes and a Year 1 class on seasons. The four plywood panels that celebrate the seasons are a riot of wild colours, decked with characters dancing under sun or in the snow.

Work with older children was invariably more complex. One Year 1 class was working on the seaside. Their visit (in the traditional howling gale) was complemented by a classroom collage where mermaids and crabs (drawn from still-life models) rubbed shoulders with fish and bathers.

“I didn’t just want to splash about with powder paints,” says Mr Cobb. “It doesn’t show the children’s work off well. On the other hand, they often draw very well, so getting them to cut out and use shape was good.”

As with the reception class, he then copied the original collage on to plywood sheets, using acrylic paints and varnish to emphasise the colours, and stuck them up in the shelter.

The Year 2 trees, including a tiger up in the rainforest tree (because, after all, cats like to go up trees) and swans at the base of the English tree (because the children liked them) were shaped by Mr Cobb, as were the Miro-esque dancing stars now gracing the nursery playground.

The artist’s interventions, however, were concentrated on getting the children to participate. “It must be everyone, not just the ones who are good at art,” he says. “I’m very firm about that.”

When the infant murals were completed by 1996, Nick Cobb wanted to move on to the junior school. Despite having generous business sponsors for some of the materials in the first projects, however, he had been forced to dig into his own pockets for some of the resources and had devoted several hours of his own each week. So he and the school decided to put in a bid to the London Arts Board for a Pounds 4,000 programme to produce more murals with the children.

Although the school’s bid did not succeed, it proceeded with a limited project funded by Pounds 1,000 that it had set aside in its budget. The project, which celebrates the multicultural nature of the school, explored the art of Benin with Year 5 children and produced a Caribbean ABC with Year 3. The money was used to frame 40 pieces of work and to pay Mr Cobb for his time.

The work is now finished, after a long production period for, as Mr Cobb says ruefully, “It takes a long time to get things done with schoolchildren. ” His compensation was that he was drawn well into the life of the classroom.

In terms of his artistic contribution, he has been able to expand the technical vocabulary of the children, using polystyrene block printing, collage with galvanised cardboard and gleaming foil, buttons stuck on polystyrene models as well as the ubiquitous powder paints.

The work leaps off the walls, making all kind of statements about aesthetic value and community involvement, about experiment and vitality, about parents and schools and children. As Mr Cobb himself says, “If I was here to teach art, I would do more things. But I’m here as a parent or an artist - it’s different”.

Different, but immensely valuable.