A fire and/or water resistant expansion joint system for installation into a building joint in vertical and horizontal configurations is designed such that it can be used for either an inside or outside corner. The system comprises a core having a fire retardant therein. A layer of a water resistant material is disposed on the core to facilitate the compression of the expansion joint system when installed between substrates. The system can be delivered to a job site in a pre-compressed state ready for installation into the building joint.