1. VERTICAL LAYING DIRECTION: From the eaves to the ridge. The downslope lap* of the top panel covers the bottom panel already installed. The installation will always be carried out with the ribs running down the slope of the roof.
2. HORIZONTAL LAYING DIRECTION: Opposite direction of the prevailing wind. The panel to be installed covers, along the adjacent longitudinal edge, the panel installed previously.
See our documentation to get more details.