Van Build Diary 5.3: Roof Rails, Oh Roof Rails, What for Art Though Roof Rails?

Updated: Feb 16

This post goes into the difference between roof rails and a roof rack, why you absolutely should have them, and how to install them (and try to not have to). It is part of a roof-top series that includes:

5.0 – Figuring out what needs to go where on the roof and timing

5.1 – Ventilation – why 2 vents, why Maxxair, how they were installed

5.2 – 12v Air-Conditioning – a confusing and stressful topic, what we went with, why and how

5.3 – Roof Rails – why you should ALWAYS install them and how to install them (the one you’re reading now!)

5.4 – Bed Liner - why, where, and how

Without further ado, here's the post and a quick disclaimer that there are some affiliate links- I may receive a small commission (at no cost to you) if you purchase through the links provided. (Learn more here) Thanks for supporting On An Imperfect Journey!

Roof Rails vs. Roof Rack

Albeit a quick one, this post is an important one for all the beginner DIYers out there. First of all, some beginners might not actually know the difference between roof rails and roof rack.

Well, that’s a simple one: the roof rack is the thing we all might appreciate and use up on the roof to store additional items. We can attach those Thule boxes on top, or strap things down to it with bungie cords (suitcases, duffle bags, surfboards).

a vintage car with a wooden rustic roof rack installed on top in a snowy area
Rack only - I think it's fantastic!

A blue vintage minivan with a roof rack and a canoe and storage box attached. Parked in from of some snowy hills
A Rack with all sorts of stuff attached to it!

Roof rails, on the other hand, are the very thing that roof racks attach to, other items for that matter (roof-top bike-rack, roof-top deck, solar panels, etc.) Roof rails are things that MUST BE ON YOUR ROOF before you can attach additional “stuff” up there because everything else you want to attach up there can only hold if those things are attached to the roof rails.

the roof of the van with the two roof rails installed. You can also see the two vents and air conditioning installed too.
There they are! Now anything we want we can attach!

For those of you who might have bought your car with a bike rack or a Thule storage box or a roof rack already installed, then you can take a quick look at your car and see the rails running down both sides of the roof, from front to back that those other things attach to. Yes, that is a totally separate thing – roof rails!

Why You Should ABSOLUTELY Install Roof Rails

Even if you are not planning on having anything attached to your roof right now – I get it, there’s a lot to already consider and a lot already to figure out, AND . . .


Why, you might ask, am I screaming this through the page?

Because you don’t want to have to realize later on that you wanted more storage on top, OR that it might be the coolest thing ever to have a roof-top deck to sleep under the stars or star-gaze or enjoy better horizon views of the sunset, OR that solar is a really helpful way to recharge your batteries in a clean way, or that you want to have a roof-top bike rack to keep an unobstructed view from your back windows or whatever other reason you might find down the road.

Why is it a headache later on? Because you have to take apart your ceiling! The screws that attach it to the roof have accompanying nuts that have to mount in on the underside of the roof and your ceiling will be in the way!

The inside of the Sprinter roof with the screw from the roof rails sticking through.
That is going to get covered by your ceiling!
a zoomed out view of the inside of the van roof, with arrows pointing to the place where the screws are screwed in on the inside
A better idea of where they are

It is an easy, relatively inexpensive installation (and, as I explain below, you can get them factory-installed if purchasing from the factory is an option). It will save you the headache later.

So, just do it now!!!

Pre-installed or DIY-installation?

Here’s the thing. . . most of you will likely go for a shorter van – a 144” wheelbase or a 170” wheelbase that isn’t extended. In your case, you can go the cheaper route of getting after-market roof rails that are cheaper and VERY easy to install.

If, like us, you have a 170” wheelbase extended, and you’re buying it new, just get it added on to your factory-install. In the alternative, you can order it from Mercedes Benz but read on to make sure the right # of nuts are ordered. OR, you can order from an aftermarket supplier but do not give your payment until you’ve been put on hold and someone has gone down to the warehouse floor and made sure that the accompanying hardware is IN the BOX!

Again, I think you’ll find the factory install to be less of a hassle when you listen to our story:

I’m not used to buying new cars so it didn’t occur to me to reach out to the MB parts department. I guess it was a good thing, on one hand, because we probably saved a couple hundred dollars ordering the rails from an aftermarket shop.

Now, I won’t name the shop, because s#*t happens everywhere and I think this could honestly happen anywhere. But IMPORTANT INFO gathered: This shop, as is the case with many, only carries one set of roof rails for the 170 extended. It had been sitting in the warehouse for forever and, as can happen, in being shoved around a bit. . . the hardware fell out. . .

So, our lovely rails arrived with no hardware!!!

Two weeks and several phone calls later and the shop still hadn’t gotten ahold of MB to get the hardware. That’s when it occurred to me, oh, I should contact Mercedes Benz myself!

A 90 min. conversation later, they had more or less figured out what I needed but I needed to go to the location to put in the order, which is no easy task fitting into our schedules. An hour-long visit to the dealership and I find out the rails cost more. So, I order the hardware only.

Guess what? The parts department can’t figure out how many nuts I need. Now, the screws come fixed to the rails and any old stainless steel (rust-prevention) washers can work. The important piece is the