This paper is concerned with the role of friendship in the construction of social capital within schools for students in poverty. It undertakes an analysis of friendship through the lens of students who have experienced turbulence. "Turbulence" refers to a type of pupil mobility between schools (not to be confused with social mobility) understood as when a child enters or leaves school at a non-standard time. An examination of the ways in which "turbulent" children seek to make friendships provides an opportunity to consider the ways in which different types of friendships affect the construction of social capital in school. This paper examines these processes for six "turbulent" children from low-income families, and explores the different orientations to the construction of social capital between these children and their non-"turbulent" friends. This study extends our understanding of the role of friendship in the construction of social capital and may help to develop an agenda for considering the importance of friendship, social capital and education for children in poverty. (Contains 3 tables.)