I have recently decided, due to the astronimical costs of hydro in Ontario, to further insulate my shop. My exisiting shop is 2x4 framed, with R14 roxul and 6 mil vapour under drywall. (No AC) The exterior is poor mans board and batten. (1/2" plywood with 1x2 battons at 16"oc.) This combination, with a 4000 watt fan heater, costs about an additional $150 to $200 in hydro per month if I heat it to 16 degress C for 6 to 8 hours a day and maintain 'frost free' at night.
If I remove the battons, add 2" of foil clad ISO and vinyl siding to add R13, should I be concerned about moisture? What else should I be considering, beside a more economical heat source?
Thanks you in advance for your help