PURPOSE: To make it possible to fix a roof boarding firmly by bending the end of a front fastener section in the shape of about U to form a lower piece, bending a rear fastener section in about inverted U-shape to fit to the front fastener section, and fitting a clip to the rear fastener section.

CONSTITUTION: The front end of a roof boarding A is bent in about U-shape to provide a front fastener section 1, and the rear end of the roof boarding A is bent in the shape of about an inverted U to provide a rear fastener section 2 for fitting to the front fastener section 1. After that, the clip 4 consisting of a fitting section 5 formed in the shape of about an inverted U and a fixed section 11 is fitted to the rear fastener section 2 so that it is slid from an upper piece 2c side of the rear fastener section 2. The space 6 is formed downward of a lower horizontal piece 1a, and a lower piece 9 is formed downward of the end. According to the constitution, the invasion of storm water into a joining section B of the fasteners can be prevented.