8018, like the other walls in the northern portion of Area I, was constructed in a late phase of the building. It predates the Cocciopesto basin, and may originally have delimited a different sort of space.The basin and the opus signinum lining slant away from wall 8018, likely to better direct fluid down the lead pipe. If wall 8018 was constructed with this sort of space/ use in mind, it should have a different alignment, or at last be closer to the alignment of wall 8038. The function of the ceramic tiles is less clear. Perhaps they marked the base of a niche?