Building workers constitute between five and ten per cent of the total labour market in almost every country. We rely on them to construct the infrastructure of our societies yet we know little about their culture. The sociologist, Darren Thiel, talks to Laurie Taylor about his study into their every day lives on a London construction site.Also, drawing on research with musicians in the North East of England, Dr Susan Coulson finds that co-operation, creativity and entrepreneurship make uneasy bedfellows.Producer: Jayne Egerton.