For at least the 4th time this year, I have spent 2 days weeding my block paving. It's just bricks, so loads of joins where weeds flourish - and I have the b.p. for my very long drive, patio and the 20 metre long path down my back garden. Is there any way of preventing weeds? I've tried assorted weed killers, but the space to be covered is so large, and even weed killers don't last. But I am fed up of spending so many days of my life digging out weeds from between bricks! Any ideas (apart from replacing it!)?