The development of new transparent space grid structures with in-plane load bearing glass panes requires sustainable knowledge about the load application into the glass edge. To apply heavy loads into the brittle material glass the block materials need to fulfil certain, partly contradictory characteristics. In the research the usage of glass fibre reinforced poly-acetate delivered appropriate short time characteristics. In the paper additional long time creeping investigations are described. To estimate the behaviour of the materials over the structure lifetime of 50 years two different materials laws are compared to the measured creeping-modulus curves.