In the frame of the SUBGLACIOR project, a new type of casing has been installed for testing during the 2013/14 austral summer season at Dome Concordia station, Antarctica. The SUBGLACIOR probe requires a full fluid column up to the surface, in order to circulate fluid for ice-chips recovery. This makes it essential that the casing is leak-tight through the porous firn column. We have evaluated existing solutions before opting to test a new method. This new system is made of polyethylene pipes which are welded together at the surface while the casing pipes are lowered into the reamed borehole. It is simple and lightweight and allows the casing to be installed quickly with optimum chance of being leak-tight. The installed casing has been tested both with compressed air and drilling fluids and has proven to work.