Nonflammable wall covering

[glwglw002]

I am putting an addition over my garage. The attic portion is insulated with a faced material. My inspector says it needs to be covered with a Nonflammable material and suggested a flexible material usually used in basements, if I don’t want to use drywall. Any information on this nonflammable material?

[bigmtk]

You can use FSK paper.

[glwglw002]

Thanks, Most helpful...