Wood beams in historic structures should be preserved without changing external appearance. An internal reinforcing system that anchors a new beam end into the sound end to restore the load bearing capacity is described. The Bureau Beta system uses an epoxy mortar combined with fiberglass reinforcing rods to restore strength to decayed timbers. This system was used in repairs to wood in two Dutch buildings, the town hall in Haarlem and the Church of Saint John, Gouda. The preservation work on the beams is summarized.