What kind of insulation?

[4arstrm]

I have a 2006 Classic A/S that lost it's rivets holding the underside panel to the trailer frame. It's a 19X31 inch panel that I can re-attach but it held the insulation under my shower. What type of insulation should be put into that space?

[Danakiel]

I had a '98 Safari which lost several sheets of the aluminum under the frame. The rivets gave way after I collected a lot of ice during a blizzard in South Dakota. None were under the shower, but they all had fiberglass batts between them and the trailer superstructure. Hope this helps.