Grate/holes along the inside of Relay/ducato/boxer models

First van conversion chin scratcher! What do I do with these holes? Just insulate them? Do I need to be worried about water coming in via the trim from the outside? Am I over thinking this…


Greetings & Welcome!

Those holes are designed to allow air movement to all metal parts inside the van to prevent moisture build up. Your design must incorporate it, not defeat it.

As for leaks, all the newer Euro vans seem to suffer from leaks anywhere there are outer body penetrations, most notably where trim is attached, or there are plugs where a roof rack might go, and sometimes where tail lights and other exterior lights are attached. I would double check these and reseal them regularly.

Good luck, and keep us posted.


"It’s nice to be important but it’s more important to be nice." ~ Nature Lover

Hi welcome to our little community

Look up “Humble Road” on you tube he has a great channel about all this stuff

lots of people seal the build up really tight and then wonder why they have issues ventilation is the key even in winter.
Insulation is a pretty complicated issue and there are many who get it wrong

Greg Virgoe is another chap you should be listening to he has a brilliant channel with lots of good advice (he has a sprinter)

Like most of us youtube will be your new best friend

Thank you! Onwards it is!