Locate on the roof where the solar array will be installed. Be sure to adhere to all local rules and regulations that correspond to your location in regards to measurements and spacing from roof eaves and ridges.
1. Mark the location of the first row of roof mounts by placing a chalk line horizontally across the roof. This chalk line should be 1.5" (38 mm) up from where the lower edge of the solar array will sit.
2. Mark the location of the second row of roof mounts by placing a parallel chalk line above the first, using the following guidelines:
- For portrait configurations, mark 66" (1675 mm) up from the previous chalk line.
- For landscape configurations, mark 40-1/8" (1020 mm) up from the previous chalk line.
For additional rows, repeat this step as needed.
3. Mark the center line of each rafter along each of the horizontal chalk lines. These marks should be within an 1/8" of the rafter center line.
4. Identify the first mount location by locating the closest rafter underneath the outside edge of the first AC Module in your array. Mark the center of the first rafter that will support the lower-edge corner of the first AC Module in your array. Ensure the location does not exceed the maximum cantilever distance of 15.75" (400 mm) for portrait configuration or 19.69" (500 mm) for landscape configuration. If a rafter does not fall within the maximum cantilever distance based on the current chalk line position, the AC Module location will need to be shifted in order to reduce the cantilever distance.
5. Once the first roof mount location is marked, continue to mark additional roof mount locations along each horizontal chalk line observing the maximum mount spacing for your location until the desired array layout is complete. Check the opposite end of the array to ensure the cantilever distance has not been exceeded at any other locations in your array.
Refer to the Knowledge Base article "Installation: Span Tables" to determine the mount spacing for your particular location. This will provide you with the maximum spacing for your roof mounts.
6. Once proper spacing has been determined, place each roof mount in position over the chalk lines to use as a guide when marking the shingles to cut for the roof mount.