- Install rails onto the mounting points, but leave the rail hardware loose to allow them to rest low on their mounting points.
- Line up the top and bottom rails in the middle of their height-adjustment range. Get down low and sight across them to ensure they are in the same plane and to avoid “potato chipping” of the array. Take time to get these top and bottom rails straight and in the same plane, and the rest of the layout will proceed more easily.
- Run a string line between the top and bottom rails or use a spare rail to line up the rails between and tighten them to their mounting points. If the middle area of the roof has a significant sag or upward bow, you may need to raise or lower the top and bottom rails to get everything to line up within their ranges of adjustment.
- Once you think you have everything lined up check again to make sure everything is in the same plane - be sure to check from both ends of the array. It is often helpful to view the rails from the ground to see how the rails are lining up.
- Roofs aren’t necessarily level to begin with, so using a level may not be helpful. If you want the array to look good, it’s more important that it match the lines of the roof.
- When you are done, check the torque on every fastener on the roof. Tightening the bolts and nuts to manufacturer specifications is critical to a secure and safe installation. Many of these fasteners will be inaccessible once modules are installed.
