[KAYE RIVERCITY]

......well first rip out the Styrofoam and use Polyisocynate board or spray for starters/glue it in place and then fill any gaps with spray can foam....OR just use a SPF system to do the job.....styrofoam is about a <R-4 per inch and squeeks when the coach moves unless wrapped in polyethylene which wears out....SPF does not powder/squeek or make deadly fumes when it burns and will add considerably to the strength of the structure-it is a relative of epoxy glue and has a blowing agent added to make it foam along with a fire retardent chemicle....far superior to styrofoam....is runs retail about a $1.00 per board foot with a R- factor of 7+.....So 2" will more than make the coach into a superinsulated structure-allowing for less A/C and Heat...FYI geof