In a digitalized society our work environment is highly integrated with our home environment making work boundless both in terms of time and space. The digital work environment risks increased stress. Based on a case study in Swedish schools we investigate how teachers experience the use of social media for work-related purposes. We do so by using the Technology Affordance and Constraints Theory to capture the affordances as well as constraints of this use. Findings show that affordances of social media in schools were increased opportunities for learning, transparency and community building. Constraints were distractions from learning, increased isolation, stress and, above all, lack of guidance in how and when to use social media. We end the paper arguing that lack of policies and guidelines governing the use of social media at work is risking an increase in boundary blurring and potentially more stress.