Abstract: A roof sheathing test system (10) is provided which may be manually operated and is substantially non-destructive in nature for load and deflection testing of roof sheathing (12). The roof sheathing test system (10) includes a test frame (14) which is mounted to a pair of displaced roof structural members (16). The roof sheathing test system (10) is mounted to the roof structural members (16) by a foot member (30) which is fixedly secured to the roof structural members (16) and the foot member (30) is releasably secured to the overall test frame (14). A load cell system (52) is secured to the test frame (14) for registering a force load applied to the sheathing (12). A load base mechanism (72) is in contact with the load cell system (52) and an upper surface of the sheathing (12). Rotation of a threaded rod (82) located within a load base rod member (76) is rotated to apply a force to the sheathing (12) which is registered on a load cell gauge (54).