The filtered Navier-Stokes equations were solved using the techniques of large eddy simulation to model flow through an aged pipe at a Reynolds number of 6800. The large eddy simulation produced DarcyWeisbach friction factors that were 20% less than the friction factors obtained from experimental tests. Much of the error is believed to be a consequence of filtering the smallest roughness elements when meshing the pipe wall boundary and possible deficiencies in the subgrid-scale model at modeling the complex three-dimensional flow structures due to the irregular pipe boundary.