module 86 may further be provided with other apertures 86 1 which may also be placed in alignment with corresponding apertures 82 in the third large size cast repair module 80 as can be seen from an inspection of fig1 and 13 through 22 two courses of ceiling repair modules of the design set forth above are utilized after these two courses have been laid a second set of interfitting ceiling repair modules may be utilized each of which includes a generally rectangular apertured ceiling repair module 96 which is adapted to be placed over the bridging module 84 the cross shaped modules 86 and the block ceiling repair module 88 with a portion of the circular aperture 96 1 in the rectangular apertured ceiling repair module 96 being in alignment with the semicircular cut out of the first rectangular bridging module 84 to provide for a passageway for coke oven gases spacer modules 98 may be provided to either end of the module 96 and in addition flue modules 92 are provided to complete the course the balance of the roof may now be completed by laying up additional courses of flue modules 92 until the last course is flush with the top of the roof of the battery a fiber tube 100 is placed in position so that it extends slightly into the circular aperture in the rectangular aperture block.