The present invention relates to a wall reinforcement system, in particular for tying a veneer wall (21) to a back up wall (22). The system can protect a building against adverse seismic or wind loading conditions. A helical wall tie (1) is driven into a back-up wall (22) using a percussion tool. A connector (10) is then placed over the end of the wall tie, the connector engaging with the helical fins to prevent its removal without unscrewing the connector (10). A reinforcement wire (20), which preferably extends around a building, is then threaded through a hole in the connector to lock the rotation of the connector (10). The reinforcement wire is used to link a series of connectors together. The wire is then encased in mortar (24) within the bed joint between two courses of bricks. In preferred embodiments, more than two reinforcement wires extend in parallel along the bed joint.