June 24, 2024

Drill One Hole In Your RV Roof For Many Cables

Let’s face it. Drilling a hole in the roof of your RV is terrifying. Some times though, the best route from point A to point B is through a carefully placed hole in your roof. I’ll show you the best way to drill a hole in your roof and run cables into your RV.

Before you charge forward and drill a hole for a couple of cables, take some time and think ahead. Chances are you’ll add more equipment to your RV roof and need another hole or two.

Plan ahead and create one large hole for the cables you need to run now and in the future. Install a professional looking cable access box and cable conduit to accommodate several cables. I’ll show you how.

Before Drilling, You Should Do This

  • Plan your cable runs carefully and consider all alternatives
  • Make sure you have more than enough cable to reach your destination
  • Get to know your existing cable paths
  • Choose a central location on your roof that is over a wall or behind a cabinet
  • Make sure you have the right tools and materials on-hand
  • When possible use a borescope to locate obstacles inside walls and other tight spaces

Things You’ll Need

Have a Solid Plan Before Drilling the Hole

A project like this takes careful planning. So before you start drilling make sure you know exactly where your cable is going to run. Pick the best route and figure out how much cable you’ll need to get there.

Photo of drilling a hole in your roof

TIP: Take time and consider all alternatives before drilling that hole. In my experience, the first solution isn’t always the best. I’ve found that the longer I think about it, the better my solution gets.

Finally, use existing cable runs whenever possible. It will save you time and prevent unnecessary drilling. So pull out some drawers and remove some panels to find those cable runs. It will pay off in the long run.

Why I didn’t use a cable entry gland

Cable glands like the one pictured are often used for cable access holes in your roof. You can find them for just a few bucks on Amazon. They are a handy for smaller installations, but here’s why I don’t use them on my RV.

Photo of cable gland

These small cable glands only accommodate one or two cables. Plus you can’t add more or get to the opening without completely removing the cable gland. Eventually, you will add more equipment on your roof and need another hole and cable gland. More holes. Not good.

The larger cable box and access hole will “future proof” your installation and easily accommodate future equipment or solar cables.

Creating the Cable Access Hole

Once you’ve got your plan, your materials, and tools, it’s time to drill a hole in your roof. YIKES! Not to worry. If you’ve got a solid plan then you’re ready to do this.

Follow these steps to create the cable access hole

  1. Using a small drill bit, drill a pilot hole from inside the RV and confirm the correct location of the hole on the roof
  2. If you have a rubber roof, cut away a small round section of the rubber membrane just big enough to keep the hole bit from grabbing the membrane
  3. Drill a 1″ hole from the roof
  4. Insert the 1″ inch PVC conduit into the hole leaving about 1″ above the level of the roof (the extra length above the surface will keep any moisture or condensation from getting into the hole)
  5. Drill a 1″ hole in the bottom of the electrical box
  6. Place double-sided Eternabond or 3M VHB tape on the bottom of the electrical box to secure it
  7. Seal around the conduit with Dicor sealant
  8. Place the box over the conduit and press down until some Dicor comes up through the cracks (the sign of a good seal)
  9. Add more Dicor around the conduit on the inside of the box
  10. Seal the outer base of the box with more Dicor to create a waterproof seal
  11. Finally, put a bead of sealant around the conduit inside the RV

Run the Cables Through the Roof Access

The next step is to run the solar or antenna cables into the RV through the new access hole.

Running cables through the roof
  1. First drill holes in the side of the box for cables big enough to fit the threaded end of the cable gland (make sure to leave room for future cables).
  2. Insert the weatherproof cable glands and tighten them down
  3. Run each cable through a cable gland and into the hole (don’t tighten yet)
  4. Finish running the cable to where it needs to go then tighten the cable gland around the cable

TIP: Use an inexpensive borescope camera to navigate around hidden obstacles in your walls. It’s been a game-changer for my wiring projects. Here’s a link to the borescope I got on Amazon.

USB Borescope Inspection Camera

Final Tips and Suggestions

There are always lessons learned on each project. Here are a few that I’d like to share to help you get a professional result the first time.

Photo of cable access box
  1. Don’t rush into this project. Considering all alternatives before starting will give you the confidence you’ll need to drill that hole. You might even find a better way to get those cables into your RV without drilling a hole in your roof.
  2. Make sure you have more than enough cable to get from the roof to your equipment. You certainly don’t want to come up short. More is better in this case.
  3. What you learn about your existing wiring will benefit you on future projects. Let’s face it, running cables through walls and cracks is not easy work. Your decision to go the extra mile to keep those cables out-of-site will produce a professional result.
  4. Routinely inspect and seal around cable box. Any hole in your roof is a potential leak, so keep an eye on it.