Mounting rigid panels is one of the more approachable parts of a DIY RV solar build — but the two mistakes that cause the most regret (roof leaks and fried components) both happen at steps people rush through. Here's the full sequence.
This covers mounting rigid panels and running wiring to the roof entry point. Full electrical wiring (controller, battery, fusing) carries real shock and fire risk — if you're not confident with 12V DC wiring and proper fusing, have a professional complete that portion even if you DIY the mounting.
What You'll Need
- Rigid solar panel(s), sized to your battery bank pairing
- Z-brackets or a mounting rail kit rated for your panel's frame
- Roof-rated sealant compatible with your roof material (check whether your roof is EPDM rubber, TPO, aluminum, or fiberglass — sealant compatibility varies)
- Cable entry gland or existing roof entry point
- MC4 connectors and appropriately sized solar cable (10–12 AWG for most panel-to-controller runs)
- Drill, stainless self-tapping screws, tape measure, chalk line, multimeter
Step 1: Confirm Your Roof Type
Sealant and screw choice both depend on what your roof is made of. EPDM rubber roofs need a sealant formulated not to degrade the membrane over time (some general-purpose sealants will). Fiberglass and aluminum roofs are more forgiving but still need proper sealing at every penetration. If you're not sure what your roof is, check your RV's owner's manual or manufacturer specs before buying sealant — using the wrong type is a common cause of slow leaks that don't show up until months later.
Step 2: Plan the Layout Before Drilling Anything
Dry-fit your panels on the roof first. Mark positions with painter's tape, and check clearance around the AC unit, vents, and antenna — both for the panel itself and for a few inches of service access around obstructions. If you're working with limited or irregular space, our guide to tight-roof layouts covers how to split panels around obstacles without losing efficiency. Once you're happy with placement, mark bracket mounting holes with a pencil or scribe — not just tape, since tape can shift.
Step 3: Mount the Brackets
- Pre-drill pilot holes at your marked bracket points, sized slightly smaller than your screws.
- Apply a bead of roof sealant around each hole before inserting the screw — sealant goes down first, not just over the top afterward.
- Drive stainless screws through the bracket into the roof, then apply a second sealant layer over the bracket base and screw heads.
- Let the sealant cure per the manufacturer's instructions before mounting the panel — usually 24 hours for a full cure, though it's typically tack-free much sooner.
Step 4: Attach the Panels
Secure the panel frame to the brackets per your bracket kit's hardware. Leave a small air gap between the panel and roof surface if your bracket design allows it — airflow underneath helps panel temperature (and therefore efficiency) more than a fully flush mount.
Step 5: Route Wiring Through the Roof
Use an existing roof entry point (many RVs already have one from the factory, often near the AC unit or a dedicated cable entry plate) if at all possible — every additional roof penetration is another potential leak point. If you must create a new one, use a dedicated cable entry gland designed for solar wiring, not an improvised hole.
- Feed the panel's MC4 leads (or bare wire, depending on panel type) through the entry gland.
- Seal thoroughly around the gland base, inside and out.
- Inside the RV, route wiring to the charge controller location, keeping runs as short and direct as practical.
Connect components in this order: battery to charge controller first, then panels to controller last. Disconnect in reverse. Connecting panels to an unpowered controller first can damage it — this is one of the most common DIY wiring mistakes according to installer forums.
Step 6: Test Before You Close Everything Up
With the battery connected to the controller and panels connected last, use a multimeter to confirm the controller is reading panel voltage and showing a charge state. Check this in reasonable sun before you consider the roof work finished — it's far easier to fix a wiring issue now than after you've buttoned up interior panels.
Step 7: Re-Check Seals After the First Week
Roof sealant can shrink slightly as it fully cures, and vibration from driving can reveal a spot that needs a touch-up. Inspect all penetrations after the first week of use and again seasonally — this five-minute check is the difference between catching a slow leak early and finding water damage months later.
Get panels and mounting hardware in one order
Renogy's rigid panel kits typically include brackets, MC4 connectors, and cable, which simplifies sourcing everything for a mounting job like this in one purchase.