A ceramic fiber insulation module is now provided from ceramic fiber units of finite length. The formation of the module can be initiated by folding an individual ceramic fiber strip or blanket, which is in unfolded condition, in a manner doubling the ends over on themselves. Then the double-over ends are folded up towards each other. As a result, the module, in cutaway, may be described as a "B-fold". The module presents an unbroken blanket surface for the hotface. The module also lends itself to fastening by cross-tying, between adjacent modules, to a backing member. Cross-tying can provide joint compression at the through joints which occur between modules.