We consider the kinetic roughening of growing interfaces in a simple model of fiber deposition [K. J. Niskanen and M. J. Alava, Phys. Rev. Lett. 73, 3475 (1994)]. Fibers of length Lf are deposited randomly on a lattice and upon deposition allowed to bend down locally by a distance determined by the flexibility parameter Tf. For Tf<∞ overhangs are allowed and pores develop in the bulk of the deposit, which leads to kinetic roughening of the growing surface. We have numerically determined the asymptotic scaling exponents for a one-dimensional version of the model and find that they are compatible with the Kardar-Parisi-Zhang equation. We study in detail the dependence of the tilt-dependent growth velocity on Tf and develop analytic arguments to explain the simulation results in the limit of small and large tilts.