What type of insulation is this?! Should I remove?

[No_Mad_People]

Hi Skoolie World. I pulled the trigger on a 2005 Checy C5500 Shuttle bus and I've been working through the demo process for a month now (I have only been working on it during weekends, and by myself). I've come to the first obstacle I can't seem to research my way out of. After all the builds I've watched and processes I've researched, I haven't come across this.

So after removing the ceiling and wall coverings, I found an almost continuous layer of fiberglass that is not the outer shell of the bus. It completely covers the metal ribs I am trying to expose and blocking the outer shell.

In between the two layers of fiberglass there is a plastic honeycomb looking insulation. I am wondering if removing all of this is a bad idea. It actually seems like it would be pretty effective. And if it wasn't for my need to expose the metal ribs, and gain access to the outer shell, I would probably leave it alone.

ANY ADVICE would be so appreciated.

[Simplicity]

I'm not sure what type of insulation it is, but it looks like there's mold. I it is, it must be removed and fully treat the bus to eliminate further spread.

Make sure you wear protective clothing, mask, eye wear when removing it, especially if it's fiberglass.

[BeNimble]

The plastic honeycomb is not insulation, in fact it has low insulation value.
It is structural material for the walls.

Not sure what else to tell you.

You could remove it all, but not sure the point of doing all that work, or why you need access to the inside of the outer wall fiberglass.

[Oscar1]

What BeNimble said! It's likely a bonded foam core and it will be structural. Removing it will give you nothing but nightmares and most likely will destroy your bus.
Tread softly here.
Good luck

[Simplicity]

Assumed it was a school bus, but I guess it's like a shuttle bus and fiberglass??

Yeah, don't remove anything structural, but if that is mold, you really need to address that.

Best of luck.

[No_Mad_People]

Thank you guys for weighing in. I think I am going to start with removing the areas with the mold and see if any learnings come out of that.

I was thinking about using a stud finder to locate the metal ribs as well. I really just need to know where they are to install a sky light, as well as, installing mounts for my solar.

I agree it would be a pain to remove all that, but if that plastic honeycomb has a low R value, maybe I should... I'll start with the mold.

[Oscar1]

The plastic honeycomb material is likely Nida core or something similar, it is used in boat, rv, and shuttle bus manufacturing to build a strong wall without weight. The thin Fiberglass skin and liner are bonded to the core with resin during manufacturing. As previously stated removing that core will likely leave you with no way to rebond structural support and your bus could become a wobbly walled ballon. If you have mould try and neutralize it with bleach or Enbac antimicrobial spray.
Just my 2 cents but I hope this doesn't become a what have I done situation for you.
Good luck