Recently the ceiling of our garage-turned-studyroom show sign of condensation and mold. I installed a turbine thinking if it is ventilation problem. Then check each soffit vent too. Upon investigation I found there is no insulation above the gymsum board along the exterior wall. Bought 3 bags of R-31 fiberglass and fill those holes. Also double up existing insulation because there is only 1 layer of 6″ fiberglass. Thank the Lord there is no mold, condensation in the attic. No sign of decay of roof plywood.