It's the dead of winter in the village of Waterfoot, Lancashire, and Bob Frith is holed up in an old slipper factory, oblivious to the December grey as he pores over the work of the painter Paula Rego. Now read on . . .

Bob Frith has been running Horse and Bamboo Theatre for 21 years now, a company that tours each summer in a horse-drawn convoy, and when he is creating a new show, he likes to draw from the energy of an artist in a separate medium.

This year it's Rego, a contemporary Portuguese artist whose work is a protean congress of myth and fable and the evocation of age old icons. Which is pretty much ideal for Horse and Bamboo, who doggedly work in the tradition of folk theatre, a theatre without text that relies instead on mime and music and puppetry and shadows.

Cut to the Lancashire springtime and Frith and his players are busily workshopping.

"Bob always comes at a piece from a visual angle first," says Nicky Fearn, who doubles up as a performer and tour manager. "That will always come before character development or storyline. He'll present a basic scenario, and he'll have already made the masks, and we can begin to improvise. We develop the work right through the rehearsal process."

And now it's a dank and clammy July noon and Fearn is taking a break from the harried last minute preparations for the debut performance of The Girl Who Cut Flowers. We're in Freemount, a two pub village in North Cork, the first stage on a Horse and Bamboo tour that will take them slowly around the country. Sitting around the ashes of last night's campfire, Fearn talks through the show.

"It's about a girl," she says, "and there's a magical, fantastical side to it. We go through her birth and growth and sense of discovery and then we meet a goat, who can represent anything, her fears or her sexuality, and he begins to invade her space. Then they both go on a journey of discovery and in this process, he starts to become more and more human . . . "

At this point, we get what I'm convinced is a knowing glance from Clint, the horse, who's been happily chowing down on some prime Golden Vale grass, recuperating from his labours dragging the set and props across the humid countryside.

"They say a horse is supposed to do about four miles an hour," muses Fearn, "but Clint is an old boy now and we might get three miles an hour out of him. But it's such a fantastic way to travel."

Horse and Bamboo is at quite a remove from the bustle and bitching of much contemporary theatre. In early winter, they'll tour this show by truck but right now, Clint is the transport chief.

"The horse-drawn days are so lovely," says Fearn. "You get up, light the fire, have breakfast, pack down the camp and maybe get on the road by about 10 a.m. We try to keep the distance between venues down to 12 or 13 miles."

It all sounds pretty idyllic and the Horse and Bamboo folk - numbering just four on this tour, plus Clint and Daisy the dog - like to feel they're keeping a certain spirit of theatre alive.

"A Nigerian professor came to see us last year," says Fearn, "and he was researching the English folk tradition and he felt that we were the only company left which is genuinely working within that."

The rituals and codes of folk theatre may have been lost entirely to the mists of history if it wasn't for a revival among the Romantics a couple of hundred years ago. There is a subsequent possibility that much of what we attribute to folk theatre may be little more than the fanciful projections of 19th-century laudanum quaffers.

But for Horse and Bamboo, there is a central essence to folk theatre that will keep it always vital and charged.

"Way back then, theatre would have been something integral to a society," says Fearn. "It's something everybody would have been involved in. And our main aim is to do just that, to open theatre out to people who wouldn't usually have access to it."

"Of course this isn't a new idea," she adds. "There have been many companies who have tried to do that. But they leave it after a while because there's no money in it."

Nag-drawn folk theatre is too slow and low-scale to be profitable and for this past 21 years, Horse and Bamboo has struggled by on grants and subsidies and small tour takings. It's always tight and this year, the company seems a little subdued as they can't afford to travel with live musicians, as they usually do.

Bob Frith, who remains in Lancashire this summer, helping to transform the slipper factory into a Lottery-funded venue, has always been adamant that Horse and Bamboo is not just some heritage proposition.

"We feel that what we do has a modern edge," says Fearn. "These are shows that you can, and we do, put on in arts centres. We're not parochial or backward-looking, we feel that we're experimenting with different levels of storytelling in sophisticated ways.

"If you look at the story we're doing now, it's not a complex piece but there are a great many layers to it. Folk theatre is not an intellectual form but the masks and the puppetry and the music open it out in different ways and make it truly accessible. It allows us to get at the content and manipulate it and just take it anywhere."

And now the show is over and the campfire embers fade and Clint is harnessed for the next leg as Horse and Bamboo up sticks and raise dust and home in on the Kilkenny Arts Festival. At a steady three miles an hour.