This paper presents results of an experimental investigation of upward flame spread on a vertical corner wall. The corner wall flame spread phenomenon differs from that for a plain vertical wall primarily because of the radiative and flow interaction between the walls. An experimental apparatus, capable of being set at corner angles of 60°, 90°, and 135° was designed and constructed. Samples, measuring 1.20 m by 0.30 m, of plywood, particle board, and hardboard were tested. Three burner configurations were used during experimentation — an arrow configuration, a line configuration, and a point source. Flame height as a function of time was measured during each run. Several trends were observed including — the significance of the burner configuration when determining flame shapes; the relationship between radiative interaction and different corner angles; and the capability of each material to sustain flame growth once the burner was turned off. Also, the pyrolysis front was noted at the conclusion of each test run using the charred region apparent on the sample, which revealed the dependence of the shape of pyrolysis front on the burner configuration. The study allows insight into various aspects of corner fire spread and provides data for validating flame spread models.