Flashing tape? There are companies out there that can even custom make butyl based 'flashing tape' with copper facing/backing!
You can also get flashing tape backed with EPDM instead of foil, or layer both the aluminum and EPDM to get a barrier type effect going. I don't know of an industrial/commercial place that sells flashing tape but there are quite a few companies out there who make them and most are butyl based to withstand the heat of its intended uses, usually roofing or exterior building sealing.