Condensation on HVAC system in attic
The air supply plenum in my attic has a lot of condensation building up and dripping through my ceiling. It is wrapped in foil backed insulation. I noticed a ~3 inch gash in the insulation. I suspect that I may have accidentally cut it while I was in the attic running new coax cable over the winter. Now that the summer heat and humidity are back, I think that moisture is getting in the gash, condensing on the plenum, settling in the bottom of the insulation and dripping through. The insulation feels room temp on the sides and top but ice cold on the bottom. But I'm not an HVAC expert - does this sound like what could be causing the condensation? Is there anything else I should check before tearing off the insulation?
Is installing the insulation as simple as it looks... just lay it up and tape all the seams? Or are there any tricks to it I need to know?
Thanks in advance for your help.