This article concerns an insufficiently studied link in cultural class analysis, namely that between class-structured lifestyle differences and social closure. It employs a modified version of Michèle Lamont’s promising, yet under-theorised approach to the study of symbolic boundaries – the conceptual distinctions made by social actors in categorising people, practices, tastes, attitudes and manners in everyday life. Drawing on 46 qualitative interviews with people from the city of Stavanger, Norway, the analysis focuses particularly on a horizontal boundary-drawing dynamic between middle-class interviewees. It is argued that entanglements of different types of status judgements work both to construct and reinforce social boundaries between class fractions. The findings draw attention to what Pierre Bourdieu has termed the capital composition principle of social differentiation. Though fundamental to Bourdieu’s model of the social space, such systematic intra-class divisions have seldom been discussed in detail in contemporary cultural-stratification research.