Abstract Flood risks worldwide are rising and it is increasingly recognised that the impacts of floods are not neutral. Socioeconomic and demographic characteristics determine people's capacity to deal with flood events. These differences in social vulnerability to floods need to be considered in flood risk management (FRM) to prevent the most vulnerable groups from being disproportionately impacted. However, due to a diversification of FRM strategies and the involvement of various policy domains, the experts working on FRM are no longer a homogeneous group. Where FRM was previously dominated by engineers, now various experts are involved that have different disciplinary backgrounds, knowledge bases and approaches to FRM. As a result, they also differ in their recognition of social vulnerability to floods. In this paper, we explore the different types of knowledge and expertise in FRM in three countries (England, Flanders and France), focussing on the strategies of flood defence and flood risk prevention. We characterise the epistemic communities supporting the domains and study to what extent experts differ in their recognition of social vulnerability to floods. We also dive into the mechanisms employed to stimulate integration between experts and consider the extent to which this integration can strengthen recognition justice.