A thermal gradient is inherent to the solidification of extruded profiles such as pipes. Depending on the magnitude of the gradient, varying levels of residual stresses are frozen-in during the pipe fabrication step. In this investigation, the residual stress state of a polyethylene (PE) pipe was altered by changing its wall thickness. Creep rupture testing of the subject pipes of varying wall thickness provided an insight on how residual stresses influences both ductile and brittle fracture processes.