The Rough In phase of a bathroom renovation project is the time at which all plumbing that is not seen when the project is completed is installed. This includes water pipes, drain pipes, vents, and any valves that are wall mounted. In some cases, drains and water lines will need to be run under the floor and will require concrete removal and pour back. This is called a Slab Rough In. Most of the plumbing will go in walls or the ceiling and is called the Wall Rough In.