- One-piece shower-and-tub units are big and often cannot be maneuvered into place later in the construction cycle. They also frequently "change size" -- that is, the size drawn on the plans and the size delivered often differ significantly.
- A full tub is heavy. Therefore, the tub is installed and filled so that the frame can settle quickly. This step prevents cracked walls and tile the first time someone uses the tub.
Typically, rough plumbing involves installing all sewer lines and vents as well as all water supply lines for each fixture. Here's a typical sink fixture:
Here's the fixture for a washer:
The tub is put in place and filled. Note the framing problem being corrected on the left side of the tub because the tub changed size:
Here are the lines for the tub:
In the crawl space, the supply lines all branch off from common pipes running the length of the house:
The sewer lines all join together...
... and then exit out the back of the house, ready for connection to the septic tank: