The invention titled "Roof System for a Log Building Toy" (hereinafter "The Roof") under this section consists of the design of the parts and the unique process of assembly of The Roof. The design of the pieces of The Roof include logs and slats that provide a new and unique manner of assembly of a log building toy or construction play set. The name of the pieces, proper identification, their description, functions and physical characteristics are described in detail on The Specification attached as well as in the nine drawings submitted along with the application. The process of assembly consists on the edification of The Roof by placing and positioning two Lateral Support Logs on sides on top of building's structure, a Central Support Log on the center on top of building's structure, and then placing the Special Roof Slats a the top of the building, which are held together in place by the Lateral Support Logs to get The Roof fully assembled. This process of assembly is detailed stage by stage on The Specification as well as in the attached drawings submitted along with the application.