Rigid foam insulation should be cut to the proper width so that it is snug, or it should be sealed in place around the edges with expanding foam. This product is for fiber glass insulation.
yes they can be cut
they are made 16" and 24" lengths
Yes. The 16 inch WILL work fine, for 15 inch. They bend.
Only to hold insulation that is inserted under the floor - not for structural applications
no, they are NOT galvanized
no - they will rust as they are simply made of steel wire
yes is was per box of 100.
One box, maybe two should do it.
These are made to go between 2x12 joists, spaced at 24"