Wood is one of the earliest and most common building materials on the planet. However wood also quickly decays under normal service conditions, and thus the repair of historic structural elements pose a difficult challenge to preservation professionals who aim to also preserve the authenticity of the element. Since the 1970s, numerous studies have looked at the use of epoxy with respect to historic timber repair. Epoxy, for the purposes of structural repair, serves as a substitution type repair for deteriorated wood. In this study focuses on the compatibility of historic structural timber members and epoxy repairs by the means of a reviewing and analyzing the state of the art of epoxy and wood durability and structural functional performance over the past couple of decades as a means to reconsider epoxy use in the preservation of historic structural timber members. Epoxy repairs to historic timber members are categorized by their application; consolidation, structural adhesive and gap-filling structural adhesive. The intent of this approach is designed to consider how the increase in the unit volume of epoxy to wood ratio affects the properties that affect the structural performance and compatibility of such repairs.