I did a search and found same ol stuff for insulating. I really don’t want to pull the plywood. Wondering if there’s a reason perlite can’t be poured into the walls. Thanks
Thought I would fill it then take it for a spin then top it off knowing that it may still settle some.
Best way, no shortcuts lol, Duct insulation..comes in 4' wide rols, 1.5" or 2" thick with aluminum backing. Use aluminum tape to tape it to the ribs. Obviously wont fall/settle. I also wrap and seal everything with reflctix on top and than screw plywood back on. Did couple of vans that way and it works fantastic in hot and cold climates. Whole thing gives you about an R8 but feels a lot better...also very quite! Add an rv fan and you're golden.
there's some good foam board insulation backed with foil/aluminum.. don't need to pull all the plywood off, just top boards. Cut a few horizontal slits in the foam insulation so it will fit down between the lower plywood and outer wall (won't slide all way down if fully intact). did this on my prior 24' trailer. Hold top part of insulation in place as you put top plywood back. easy. I would think the expanding stuff would make more of a mess than worth to do for this application but who knows. That perlite if it can be blown in, might actually be worth a shot ? I used some 2" thin strips to cover all the seams in the plywood for a more finished look on that other trailer too.
+1 I did that with all my trailers. Used the foam board insulation you can get at most big box stores in all kinds of different R numbers. Just cut the foam boards to fit between the supports and then put the plywood back on. You can even cover the plywood and the ceiling with the white vinyl panels to give it a cleaner look.