I thought you would be interested to see what we discovered in our walls after our flood of the floors.
This is in our livingroom which shows the pipes of the bathroom on the other side of the wall that is in our master bedroom. Our water restoration man couldn't get the walls dry in two places and his little tubes kept filling up with brown powder, which we now know was sand. We think that the contractors that built the house got sloppy and dumbed some sand in the walls when they didn't want to go outside and do it.
We got three of these 5 gallon pails of sand out of the two places where there was sand.
This is the plumbing of the tub in the other bathroom that the toliet was in that caused the flood.