Some give when walkig on top of cabin
 

Hello, I just sold an old '88 Nova and bought an '89 Formula 242. The Nova's cuddy cabin top was cracked all over and had lots of mushy give when walking on it. The Formula is in far better condition. No cracks at all, but a bit of give when walking on it. I imagine the foam or whatever is in the sandwich of that section has lost its volume. Question, is there an easy way to improve this situation to avoid future cracks, I had the idea of drill holes from inside the cabin and squirting expanding spray insulating foam inside to increase the material in that sandwich. The area tested dry with a humidity meter so its not rotten and like I said there are no cracks yet. Is this a decent idea? Or could it cause other problems?

I don't think there is a "sandwich " on the deck. I believe the headliner material is glued directly to the underside. At least on my 86 242 it appears that way.

I see, my Nova had the top exterior, wood and foam then fiberglass inside the cuddy with carpet glued to it. Ill get my wife to walk on it while I check for her feet indentations from the inside then.