i have framed in a room in a stucco house with steel studs. i am trying to put the insulation in on the exterior walls. the insulation is 15'' wide which is probably made for wood studs only i think. the steel studs are hollow, so 15'' insulation is loose. do they make 16'' insulation for steel studs? also it is the paper faced type. i can't staple it in place, so i am going to use duct tape, is this ok?
You might have a hard time finding insulation for the steel studs, but it is available. It won't be a home center item.
Duct tape won't retain the insulation long term. If you're going to use the insulation you've already got, you might tape in in place to retain it until you sheetrock, and use spray foam to "stick" it to the studs. Great Stuff foam is super sticky and will bond to just about anything. A glob or bead of it here and there will likely do it.
Personally, I'd find a source for the correct insulation. If you can't find it, you can always cut a couple inches off of some wider batts (19.2" batts or 24" batts).