Roof Mount and Flashing Installation

Locate on the roof where the solar array will be installed. Ensure that you adhere to all local rules and regulations that correspond to your location in regards to measurements and spacing from roof eaves and ridges. For tile roof installations, refer to “Appendix B: Tile Roof”.

  • 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 be installed.

Roof Mount and Flashing Installation

  • 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 40.13″ (1020 mm) up from the previous chalk line. For additional rows, repeat this step as needed.

Landscape Configuration Roof Mounts

  • Mark the center line of each rafter along each of the horizontal chalk lines. These marks should be within 0.25″ (6 mm) of the rafter center line.

Roof Mount Chalk Line

  • 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, shift the AC Module position inward to reduce the distance.

First Mount Location

  • Once the first roof mount location is marked, continue to mark additional roof mount locations along each horizontal chalk line, observing the maximum spacing for your location until the desired layout is complete. Check the opposite end of the array to ensure the cantilever distance has not been exceeded at any other locations as well.

Roof Mount Location Marking Refer to “Appendix A: Span Tables” on page 57 to determine the mount spacing for your particular installation location. This will provide you with the maximum spacing for your roof mounts.

  • Once you’ve determined the proper spacing, place each roof mount in position over the chalk lines. This will mark the mount locations and let you know which shingles to cut.

Roof Mount Positions

  • The roof shingles need to be cut to allow proper installation of the Roof Mounts and Flashing. Use a chalk stick to mark a 3″ (75 mm) area around the roof mount (to use as a guide) and trim the second course of shingles.

Shingle Cuts for Roof Mounts and Flashing

  • Once you’ve trimmed the shingles, position the Roof Mount over the rafter center and start predrilling the two holes that will be used to secure the roof mount to the rafter. Use the shingle cutout and the two smaller holes on the roof mount as a guide for positioning.

Note: To avoid damaging the roof mount, do not drill the holes completely through with the roof mount in place. Pre-drilling holes for roof mounts

  • Remove the roof mount temporarily and finish predrilling two 3/16″ (4.8 mm) holes approximately 2″ (50 mm) deep.

Finish Pre-drilling roof mount holes

  • Cover both hole openings with roofing sealant. This will ensure a watertight installation once you’ve secured the lag screws to the rafter.

Cover holes with roofing sealant

  • Position the Roof Mount into place and tighten the lag screws until the Roof Mount is secure.

Tighten Lag Screws Until Roof Mount is Secure

  • Slide a roofing bar under the shingles to break the bond where the Flashing will sit. Remove any nails that will interfere with the installation of Flashing and lift up the shingles.

Slide a roofing bar under shingles

  • Apply roof sealant to the underside of the Flashing and in an inverted U shape around the opening.

Note:Wearing gloves is recommended as the Flashing has sharp edges and also may become hot when exposed to warm temperatures. Apply Roofing Sealand to the Underside of the Flashing

  • Slip the Flashing into place underneath the upper course of shingles and lower it over the roof mount. The Flashing should be installed with the Ubiquiti logo towards the front.

Slip the Flashing into place underneath shingles

  • Reseat the shingles to cover the Flashing. Position the Flashing to meet the following criteria:
    • The lower edge does not extend beyond the first course of shingles.
    • The upper edge is located underneath the third course of shingles.

Reseat shingles to cover flashing

  • Apply a minimum of ¼” (6 mm) continuous roof caulking around the gap between the Flashing and the Roof Mount.

Apply roof caulking to gap between flashing and roof mount

  • Install the rubber counter flashing over the neck of the Roof Mount until it is fully seated onto the Flashing.

Install rubber counter flashing over neck of roof mount