Recent scholarship has shown the prevalence of work–family conflict among social workers caused by their intense job demands. Correspondingly, academics and practitioners alike have recommended work–home segmentation as an effective coping strategy to help social workers deal with work–family conflict. Drawing on the stressor-strain-outcome framework, we first conducted Study 1 using a survey of 504 social workers to test psychological strain as a mediator of the relationship between work–family conflict and job performance, and to examine if work–home segmentation buffered the mediating relationship. Contrary to prior studies, work–home segmentation only alleviated work–family conflict for some social workers, but intensified the psychological strain and reduced the job performance of other social workers. To probe this finding further, we conducted semi-structured interviews with 15 social workers in Study 2 to understand why work–home segmentation did not reduce their psychological strain. The interviews revealed that most struggled to detach themselves psychologically and emotionally from work at home. The inability to implement work–home segmentation thus became an additional stressor, and they also engaged in after-hours work-related rumination. Therefore, we encourage organisations and managers to adopt a nuanced approach when advocating work–home segmentation as a coping strategy for frontline workers to deal with work–family conflict.