[Dave in MN]

I used X-mat sourced from Eastwood for sound deadening. Very easty to work with. Then sprayed 3-M High Strength contact adhesive on it and adhered bubble wrap double faced aluminum insulation that was about 1/4" thick. I even put it in the roof assembly between the wood ribs. The double faced bubble insulation was sourced from a local Menards. (Like Home Depot or Lowes) Both help greatly.
Good Day!