This paper provides a qualitative account of Vietnamese language maintenance in Manchester. Through ethnographic observations of distinctly Vietnamese locations, Vietnamese language practices are shown to create spaces in which Vietnamese is the dominant language, and in which Vietnamese norms and expectations, or scales, are able to influence and contest other behavioural norms. These scales are viewed as social practices, and they are derived from interviews with Vietnamese speakers and observations of Vietnamese spaces, and special focus is given to the linguistic resources used to conduct them. The analysis reveals ideas of language competence and politeness which compete and interact with norms from outside the spaces, and non-linguistic behavioural norms which contribute to language maintenance. Vietnamese is shown to be maintained through micro-interactions which make the heritage language the norm, and business and religious practices are found to promote heritage language use by requiring heritage language practices to participate.