Surly is the queue; there is no sense of fellow feeling here. Seething and resentful, the men with the potted plants and bargain packs of self-driving wood screws are not united by their labours but divided by their desire to get to the checkout first and then outside to negotiate a car park where unruly crowds ram lengths of skirting into Vauxhalls.
This is one of the busiest bank holidays of the year and the surge of weekend nailers and drillers is threatening to overwhelm the medium-sized DIY store. Those teenagers at the tills who haven't taken the precaution of getting stoned are wide-eyed with panic, and the manager, an eight-foot-tall youth coated with pimples, dances between the aisles misdirecting the lines until they merge into one über-queue.
Holding an everlasting light bulb, I join the melee between a man carrying a polystyrene plaster-effect rose ceiling feature and two young women - students, I suspect - who have come for a cheap saucepan set and are now discussing whether to splash out on a small cactus for the windowsill.
But the debate that really matters is in the minds of the men around us. Their eyes swivel as they assess which of the other men are tradesmen and which amateurs. Which of them, in the fullest sense, are men?
Is it the burly blokes with bags of cement and fingers flattened from years of hammering? Or the paler, slighter men, holding wrong-for-the-job packs of wall plugs and floating shelves that - though their partners do not know it yet - will fall as surely
as the glory that was Rome.
This contest is given stark illustration by two men in front of the students who stand adjacent in their respective queues. One of them is covered in dust and has keys that dangle from a ring attached to his belt. He pushes a big flatbed trolley loaded with plasterboard and timber. The other man wears clean jeans, a V-neck and pushes a standard metal trolley; it is lightly loaded with two lengths of metal curtain rail that stick out awkwardly at the front.
Deliberately or not, the dusty man is encroaching on the other's route and the man in the V-neck, annoyed, starts to nudge back. Affronted by this slight, the dusty man pushes harder and a bout of trolley wrestling ensues. The students move away and I step behind them as things are heading towards violence. Then the queues move and the man in the V-neck yelps happily as he moves to the till. He is met by the pimpled youth: "I'm afraid this till is closed now, sir."
The reaction of the man in the V-neck is sudden. Turning angrily, he pivots on his left foot, his trolley swings and a curtain rail slides off, becoming a javelin that takes a chunk from the back of the dusty man's leg. Not a big chunk, but enough, everyone notes as he screams, to hurt.