Vibration serviceability of various types of timber floor systems has claimed much attention during past decades. Yet the definition of robustly reliable engineering design approaches has remained elusive, except in well-defined situations. Successful design depends on having appropriate vibration serviceability performance assessment criteria, and ability to predict floor response parameters used by those criteria. This paper addresses prediction of dynamic response characteristics of cross-laminated-timber (CLT) floor systems using finite element methods. Attention is focussed on systems that contain realistic construction features like intra-slab CLT panel to-panel joints, and variations in floor slab edge supports. Modelling assumptions are verified by comparing analytical predictions with test results.