CONSTRUCTION projects . He explains that preliminary construction work for the data centre has proved challenging with regards to timescale as a result of excavation work , which is time-consuming in Finland as a result of being the home of the toughest bedrock in the world . The first phase incorporated 100,000 cubic metres of blasting work which took approximately six months . The next phase is currently underway through the winter season , which will impact on essential concrete work . “ Casting concrete would be fine if you can do it in summer ,” Ekman explains . “ In our case , we have a long winter season and we are casting concrete in midwinter .” However , he adds : “ This is nothing www . sonera . fi 53