How to Seal Camper Van Roof Holes Using a Waterproof Cable Gland Kit

If you're installing solar panels, antennas, or rooftop accessories on your camper van, you'll eventually need to seal holes in the roof to keep everything watertight. In this guide, we'll walk through how to professionally seal those holes using a waterproof cable gland kit—without compromising your van's roof integrity.

Whether you're rerouting your factory antenna or adding solar panel wires, this process is a must for preventing leaks and maintaining a clean, functional build.

Why Sealing Roof Holes Matters

Cutting into your van's roof to run cables can create vulnerabilities. If not properly sealed, those holes can lead to:

• Water leaks
• Roof rust or corrosion
• Damage to insulation or electrical systems
• Increased interior noise

Using "marine-grade waterproof cable glands", like the ones from Scanstrut or Amazon kits, ensures you get a long-lasting, professional-grade seal.

Step-by-Step: Sealing Camper Van Roof Holes

1. Plan Your Cable Routing

Before drilling anything, identify where your antenna, solar panel wires, or LED light cables will exit the roof. This ensures:

• Wires won't get pinched under brackets
• Cable runs are as short and efficient as possible
• Your holes don't interfere with roof racks or other hardware

On Thomas's 2020 Ford Transit, for example, the factory antenna location was blocked by a new solar panel, so we relocated it to a better spot with less wind and water exposure.

2. Use Scanstrut or Marine-Grade Cable Seals

We used "Scanstrut cable glands"—popular in the marine industry—for this project. These come in both square and round styles and feature:

• Rubber gaskets
• Pre-cut or customizable holes
• Stainless steel mounting hardware
• Double seals for watertight protection

They're ideal for shielding antenna wires and solar cables from moisture while still looking clean and professional.

3. Fill Old Holes With Plugs & Silicone

When relocating rooftop components (like a satellite antenna), seal the old hole with a waterproof cable gland or a blank plug. In our case:

• We reused the original mounting hole by sealing it with silicone
• Applied thread locker to the new antenna location to ensure a snug fit
• Used stainless hardware and a rubber gasket to prevent future leaks

If the wire has a small gap around it (like with a shielded coaxial cable), fill the void with "liquid rubber" and seal over it with lap sealant for double protection.

4. Install Cable Gland for Solar Panel Wires

Instead of using a large cable pass-through box, we recommend:

• Drilling small holes for individual solar panel wires (positive and negative)
• Installing "mini cable glands" with compression fittings for each wire
• Avoiding big 2–3″ holes in the roof—smaller holes mean less risk

This not only keeps your install cleaner, but it also makes it easier to remove or replace individual wires later.

5. Add Additional Accessories (Like Baja Designs Lights)

For any other rooftop accessories (like an LED light strip), use the "same waterproof cable gland kit". These kits often come with multiple sizes, so when your light kit arrives, you'll have options for the right cable diameter.

This method allows you to:

• Run wires close to where the device is mounted
• Avoid long cable runs
• Keep a minimal number of holes in the van

Recommended Products

Product	Purpose	Notes
Scanstrut Cable Seal	Antenna relocation	Marine-grade quality, square and round styles available
Amazon Waterproof Cable Gland Kit	Solar wires and light cables	Variety of sizes, compact compression fittings
Lap Sealant	Added waterproofing	Ideal for sealing around the outside of glands
Liquid Rubber	Internal fill for small gaps	Prevents rattling and water intrusion

Pro Tips for a Clean Install

• Always pre-drill your screw holes carefully to avoid damaging thin roof metal
• Use adhesive gaskets provided with the gland kits for added sealing
• Avoid routing cables under brackets or solar mounts—keep them accessible
• Label your cable ends inside the van for future troubleshooting

Final Thoughts

Sealing holes in your camper van roof doesn't need to be complicated. With the right tools and a careful approach, you can install solar wires, antennas, and lighting without sacrificing your van's waterproofing or structural integrity.

This method gives you a neat, professional, and serviceable install, whether you're doing a DIY build or outfitting a customer's van.

Watch the Full Installation

We walk through this exact install on Thomas's 2020 Ford Transit, including antenna relocation, solar cable routing, and how to use individual waterproof glands. Check out the full video for visual step-by-step guidance.

FAQs

Q: Can I drill one large hole for all my wires instead?

A: You can, but it's not recommended. Smaller, dedicated holes are easier to seal, service, and reduce the risk of roof failure.

Q: What if I need to move the antenna back later?

A: No problem. The plug method we used allows for easy removal and reuse of the factory antenna hole.

Q: Is this method compatible with all van types?

A: Yes, this method works with most vans, including Ford Transit, Sprinter, and Promaster models.

If you have any questions, drop them in the comments or reach out to us directly. Happy building!