Repairing 1960 tiled shower stall
How do I repair the cracks in the grout of the mosaic tile in a shower stall, circa 1960? Water has seeped through the ceiling dowstairs under this bathroom. The existing grout seems much harder than the grout around the 4x4 wall tiles. Is it a different type grout? Shouldn't there be a pan under the mosaic floor portion of this stall? Is there such thing as a rubber sealer to cover the entire mosaic tile to ensure waterproofing? Thank you in advance.
debbie beard