Sagging under floor insulation

[MikeB]

While working on the frame I just noticed that their are two spots where the foam and sheet metal have delaminated from the plywood flooring. One of the spots is actually sitting on the muffler. Maybe from a leak? I can put my fingers in their and feel the plywood and it feels strong. But the insulation feels brittle and crumbly.

Not sure of the best way to fix
it. I was thinking of getting rid of the muffler and using aluminum flat stock with screws to lift and hold it back in place.

Im also considering going to a rear muffler.

Any suggestions on the floor repair?

 

[MikeB]

Some pics

 

[pvfjr]

I discovered the same issue on my Palm Beach recently, though it's not touching the mufflers yet. I was thinking about jacking the stuff back up into place, and bracing it with some 1/2" square tube or something like that. I haven't gotten around to it yet. I'm sure I've read about this issue elsewhere too; maybe on GMCnet.