Extreme floods are the most common type of natural disaster in Europe. It is projected that future floods may be exacerbated by the effects of climate change. The concept of managing rather than preventing floods is now being recognized as an effective approach and is engrained in both national and European policy. The use of effective flood warnings and communication is an essential cornerstone of flood risk management. Uncertainty is also a key aspect of effective flood risk management. The concept of "interpretive uncertainty", defined as the differences in how people understand and interpret information, is emerging as a significant component in flood risk management and is the focus of this paper. The study involved extensive quantitative research of at-risk communities in four case study areas across Ireland, exposed to pluvial, fluvial and coastal risks as part of the ERA-Net CRUE UR-.flood project. Approximately 2,200 postal questionnaires were administered across the four case study areas, with 436 returns; a response rate of 20 %. From an analysis of these results, the paper identifies barriers and obstacles to effective flood risk communication, focusing on before and during flood experiences such as risk perception, flood preparedness, information and warnings, communication methods and reacting to warnings. From these findings, recommendations are made on how these obstacles can be overcome.