I start with a crowbar and a computer monitor. It's harder than you might think to smash a monitor. It doesn't shatter. It doesn't even crack. It just develops a small, regular hole, out of which curls a dusty, glassy gas. This is not something I have seen before. Half my life in front of a computer screen, and I never knew what was inside.

Scrap Club. A festival of destruction. Extreme violence, studded with moments of serenity. Beside me - and with a look on his face that could be described only as tenderness - a smartly dressed credit analyst called Andrew is driving a heavy metal pipe into the innards of what used to be a PC. With shards of plastic on my lips and a ringing in my ears, I pause to marvel at the tumbling gas. I think of the sat-nav that has led me, as I wailed, on a merry dance around South London to this warehouse behind Peckham Library. Then I get a sledgehammer.

“I want to break stuff,” Andrew says afterwards, but he says it thoughtfully. “I think that's why I'm here. I work at a computer all day.”

It is Saturday night and the air is thick with dust and clanging. A couple of hundred people standing around an enclosure, all taking turns to be among the eight or ten who get to go in the middle and destroy. For the past couple of weeks, the organisers have been scouring London, collecting computers, monitors, televisions, washing machines, fridges, garden furniture, toasters, vacuum cleaners and even the odd piano. Grab your hard hat, don your gloves and goggles, choose your weapon and get to work.

Scrap Club began last year. This is the fourth since then, and the buzz has been steadily growing. One of the organisers is Wajid Yaseen, 39, a musician from Manchester. The inspiration, he happily explains, was the recent re-enactment of Concerto for Voice and Machinery, an infamous gig performed in 1984 at the Institute of Contemporary Arts by Einstürzende Neubauten, an 1980s German experimental noise band who made instruments out of industrial tools and were themselves heavily influenced by Dadaism. This is not Jackass. Oh no.

Although there are elements of that. One loud thirtysomething is thoroughly wired, and has to be coaxed into wearing his protective gloves, goggles and hat. “My name is Sex And Violence and I am from Hell!” he roars when I say hello, although he is plainly from Germany. And before Hell? “Brixton! This destruction, it is too sanitised! With the goggles you cannot see! I used to, as a teenager, kick cars and burn things. They shouldn't clean up afterwards. The pile, it should be knee deep. Destroy!”

Overly critical, in my view. Although you sign a waiver on the way in, and the safety kit is mandatory, this is hardly a super-safe endeavour. After an hour or two, a few people sport bruised hands and gashes to the shins. Luke, our photographer, is nearly taken out by a flailing pipe. Nobody minds. One man slams a huge patio heater with his mallet, sending it toppling on to the head and shoulders of an incredibly small girl. She staggers and smiles, and then the pair of them attack it together, as though it were a punishment.

Such little dramas are oddly touching. For the most part this is a solitary pursuit. Vision is limited through goggles, and a pair of industrial noise drummers batter away on metal pipe drum up on a balcony to one side, just in case the noise of real destruction isn't disorientating enough. Before each round, participants are asked to practise their swing, to check there aren't any heads in the way.

“Can we smash people, too?” one girl asks.

“Yes!” Sex And Violence roars.

“No!” Wajid implores. “We're doing this so we don't have to smash people. Yeah?”

This is Wajid's philosophy. “This is a transference of violence on to objects,” muses the man who has just brutalised a picnic table with a hammer. “Being better human beings. Offloading tension. The second time we did this, there was a guy in a wheelchair. You should have seen him. Smashing into a monitor with a crowbar. You notice that there are a lot of women here?”

At one Scrap Club evening half an aeroplane was smashed up. “Can you f***ing believe that?” Wajid says. “An eight-seater. It did take a while.” Wajid's weapon of choice is an aluminium pole - he likes the weight.

His co-organiser is Joel Cahen, a 35-year-old artist from Haifa, Israel. His take on all this is slightly different. “It is a response to the clutter of objects we have in the world,” he says. “It is a totally one-way relationship, yeah? A throwaway culture. Nothing is fixable any more, so why not do it properly?”

Some people bring their own scrap to Scrap Club. Most of it is provided by Wajid and Joel. Both maintain that it would be morally wrong to buy scrap, or to break anything useable or easily fixed. I've a hunch that they are just saying that. Dotted around the warehouse are smashed items, placed meaningfully on plinths. A lawn-mower. A Coca-Cola machine. Other stuff, now mangled, that could be anything.

“They are beautiful,” Joel says, gravely. “Think of the creativity and passion that has gone into making, say, a washing machine. For generations. But it is now taken for granted. By destroying it, we are extracting that creativity from within. You learn. Who knew there was so much Styrofoam inside a fridge?” Joel's weapon of choice is a sledgehammer and he likes the way that car dashboards are crumbly and intricate. “It is also nice,” he adds, “to mindlessly hit a kitchen sink.”

Albeit exhausting, especially around the shoulders. Some participants, though, are so calm that they border on the creepy. Over to one side, there is a table for quiet scrapping. Here I find three friends from East London patiently pulling apart a computer.

Rachel, 23, is a medical student with a spanner. “This hard drive,” she grunts, “is really hard.” She is here for revenge, because her boyfriend, Andrew, spends too much time on his PC. Certainly, he seems to know his way around a circuitboard. He shows me the processor, a small silver square stamped with the word Centrino. “Listen to this,” he says, gleefully, and crunches it in a pair of pliers. “Hold it to your ear, and it sounds like gravel caught under a door. Intel inside. Bong bong bong.”

Mark, 27, is grappling with the optical drive. Rachel wants him to smash it, but Mark won't. He wants to break it slowly. Are these people torturers? Or is this art?

“Maybe,” Mark says. “Although sometimes I think that is just an excuse. There is a real primal pleasure in breaking stuff. Beauty in destruction. Yeah. The urge to destroy. What do I do? Professionally? Oh, I'm a carer.”

There's mischief here, but also deliberation. I had expected retarded adolescence, just a big boys' version of kids smashing stuff up in a junkyard. This is altogether more intellectual. Nobody here is stupid. Everybody is thinking about what they are doing, and why. You can feel this in the tangible ripple of disquiet when Wajid wheels out the first piano.

Wajid is into smashing pianos. You can tell. On the Scrap Club website he has written a 4,000-word essay called On Piano Destruction, complete with footnotes, bibliography, and section headings such as “Anthropomorphic Sentimentality” and “The Moral Low Ground”.

Later, he tells me that he once did a “one-on-one destruction” with a piano, and found it a profoundly moving experience. That's how he says it. Just him and the piano. “It took me two hours,” he says. “At first it was a masculine job, but then I started to get these weird anthropomorphic sensations. I saw all the ghost players who had ever used it. By the end of it, I really felt that I'd killed something.”

Unlike much modern technology, the piano seems curiously indestructible. Or, as Mr Sex And Violence puts it, “respect to the piano. It's a big motherf***er.” Wajid, who knows what he is doing, quietly fetches a crowbar and prises it under the strings. With the sound of clanging all around, you can't hear a thing.

So yes, Scrap Club is a thoughtful affair. It sticks with you like a good book, making you wonder, days later, what it all meant. A piano lasts, and you think of history. A vacuum cleaner outlasts a PC monitor, and you think of class war. Computers, lightbulbs, televisions, burglar alarms, Tube trains, stereos, microwaves, cigarette lighters. We don't need to live in the world that they frame. I think that's the point. We choose to. If we want, we can choose not to.

And me - I trot off back through the rain to my car, and look at my sat-nav with hauteur renewed. It does not meet my eye.

www.scrapclub.co.uk