Abstract Two concrete qualities were subjected to different curing conditions and then exposed to three different climates; outdoors exposed to rainfall, outdoors protected from rainfall and indoors. After one or two years of exposure the water impermeability and the carbonation depth were determined. The test results show that the differences between different curing conditions becomes more pronounced the drier the climate. This means that laboratory tests cannot always be used for predicting the concrete behaviour of a real structure. Field exposure tests are to be preferred. According to the results from the carbonation tests, it seems that wet curing and covering with plastic foil are equally efficient.this is relevant for Swedish field conditions, and other climatic conditions probably give other results.