A gutter is provided for use with either flexible or nonflexible cover materials in forming building structures, such as greenhouses. The gutter serves as a conduit for carrying water, an important structural load carrying member, and as a means for securing cover materials to the building frame. The new gutter has a uniform cross-section along its length and can conveniently be formed by extruding aluminum through a die. The gutter includes a web and a pair of mounting plates to attach the gutter to vertical posts. A plurality of mounting brackets extend from the web and include means for securing a flexible cover thereto. The presence of the mounting plates and mounting brackets makes the gutter a strong, but lightweight structural member, and permits minimizing the thickness of the web.
