In a case study, 36 future sloyd teachers, who have taken a leading role in working with pedagogical development, describe their experience of pupils' unmotivated and disruptive behaviour. It was revealed that the teachers were disturbed by pupils whose risk-filled behaviour was aggressive or destructive, as well as by pupils who were reluctant to take risks in their constructive or passive behaviour. It was also revealed that these types of behaviour occurred periodically or permanently, which in different ways challenged the sloyd lesson as a social system. From an ecological perspective, the teachers employed various strategies in their attempts to maintain a balance, social sustainability in the classroom. They had various strategies for directly handling challenges, such as attempting to keep the pupils in the classroom, and other strategies for indirectly handling challenges outside the classroom. In this way, the teachers hindered, stopped, brought back or removed pupils who were unmotivated or disruptive. It was also revealed that dealing with these challenges was energy- and time-consuming and that it shifted focus from the teachers' didactic management of sloyd class.