An efficient and scalable broadcast are two essential features of structured overlay networks which used in large scale distributed computing systems and in peer-to-peer networks. The existing broadcast based algorithms over the structured overlays experience certain issues due to a decentralised nature of such networks in which nodes join and leave the network dynamically. This causes poor routing efficiency and high maintenance bandwidth overhead. In this paper, we study routing efficiency and maintenance bandwidth overhead while broadcasting messages over the structured overlay networks in dynamic environment. We also propose an improved message broadcasting algorithm over the structured overlay networks. The simulation results show that although there is a trade off between routing efficiency and maintenance bandwidth, with optimisation we can improve one without severely effecting the other parameter.