A building structure comprises a post having a vertically extending longitudinal face. A plurality of horizontal logs extends from said longitudinal face and has an end face in abutment with said longitudinal face. The post having an undercut channel in said longitudinal face and extends along said post. At least one of said end faces has a recess aligned with said undercut channel, and a spline assembly extends between said post and said log to secure said log to said post. The spline assembly includes a key located in and extends between said channel and said recess and an insert in one of said undercut channel and said recess. The insert co operates with said key to facilitate relative sliding movement therebetween.