In IEEE 802.16 Wireless Mesh networks (WMN), multipath routing is used to improve the reliability and load balancing. But existing multipath routing protocols for WMNs, causes congestion in the gateways because of routing and control message flooding. In this paper, a multipath routing protocol is proposed to improve the reliability and provide fault-tolerance in IEEE 802.16 WMNs. In this protocol, the interference and load of each link is determined based on which a combined routing metric is designed. Multiple shortest paths are then established and the path with least combined metric is chosen as primary path. In case of any failures in primary path, the data transmission can be rerouted through the backup path. By simulation results, we show that the proposed protocol has improved throughput with reduced delay and overhead when compared to the existing protocols.