Part 2 of the solar mount project, 1/2 way done with help from a friend!
Part 2 continues a rooftop solar mount project with a friend helping to get roughly halfway through the install. The work shown covers measuring and drilling mounting points, installing rails/brackets and rivnuts, sealing penetrations, attaching panels, and beginning the basic wiring toward a charge controller and combiner box.
Build Sequence
1. Plan layout and measure
Measure the roof area, determine panel placement, and mark mounting rail and bracket locations to ensure clearance for doors, hatches, and roof features.
2. Trial-fit rails and brackets
Place rails and L-feet on the marked positions to confirm fitment. Adjust spacing and ensure panels will sit flush and have adequate edge clearance.
3. Drill pilot holes
Drill pilot holes at marked locations using appropriate metal drill bits or step bits. Start small and step up to final hole size to reduce metal tear-out.
4. Install rivnuts
Install rivet-nut inserts into the prepared holes using the rivnut tool to create strong, threaded mounting points from the roof exterior.
5. Seal mounting points
Apply butyl tape or automotive-grade sealant around the base of brackets and over screw heads to waterproof roof penetrations before final torque.
6. Bolt rails and brackets in place
Use stainless hardware to fasten rails to the newly installed rivnuts. Torque to a snug, appropriate spec and ensure rails are straight and secure.
7. Mount solar panels to rails
With assistance, lift panels onto rails and secure them with clamps or bolts. Verify alignment, edge clearances, and that panel frames are firmly attached.
8. Run MC4 cabling and combiner wiring
Route cables from the panels to the combiner box area, secure wiring run with clamps, and terminate MC4 connectors. Leave final connections to the charge controller for next stages.
9. Initial electrical check and tidy up
Use a multimeter to check open-circuit voltage from panels and continuity of wiring. Clean excess sealant, re-check fasteners after settling, and prepare for charge controller integration.
Frequently Asked Questions
What are the essential tools I must have?
At minimum: a good cordless drill with metal drill/step bits, a rivnut installation tool, a socket set, caulking gun for sealant, and a multimeter for electrical checks. Ladder and roof safety gear are also recommended.
VIEW FULL ARTICLE →How do I wire multiple panels together?
Panels are typically combined in series or parallel depending on voltage and the charge controller specs. Use MC4 connectors and a combiner box with proper fusing, then route the combined output to an MPPT charge controller matched to your battery system.
VIEW FULL ARTICLE →Related Builds
Parts Used (10)
Two compact panels used for rooftop array in this stage of the build.
Used to create threaded mounting points in the roof without access to backside.
Stainless fasteners to secure rails and panels; chosen to resist corrosion.
Seals around holes and bracket bases to prevent leaks.
Regulates panel output into battery bank; not always fully installed in Part 2 but planned/wired to.
Combines panel outputs and houses fuses/breakers before charge controller.