I live in a 1929 brick building in which some the drain pipes (from tubs and kitchen sinks) are embedded into brick walls, two bricks thick on each side. One of these pipes has a crack in it so water floods into the basement. It needs to be repaired. It appears the only way to repair this is to gently remove the brick so that the leak can be accessed, but this is a really time consuming job. Is there any way to repair a cast iron pipe (I think it's 3") from the inside? Rerouting the drain is not an option because it would affect multiple apartments. Thanks.