Phase #2: Above-Ground Rough-In (Second Rough-In/Top-Out/Stack-Out) The next phase, the above-ground rough-in, is sometimes called the second rough-in or just the rough-in phase. Here, plumbers will begin installing the above-ground plumbing systems, which includes everything behind the walls and above ground.
The supply and drainage subsystems are two distinct operations, with no overlapping between them. There are bridges between the two, however, and the bridges are what make the plumbing system worth having. In plumbing jargon, any bridge between the supply and drainage systems is a fixture.
Defining Rough-In Plumbing
Rough-in plumbing includes the plumbing lines, vents, waste systems, and connection points for appliances. The finished rough-in includes your entire plumbing system but without the connection of appliances, toilets, and sinks.
Rough-in is the stage in construction when essential Mechanical (HVAC), Electrical and Plumbing services are installed in the building. It happens after framing is complete and when the building is protected from outside elements, but before any drywalls (plasterboard) are installed.
Once rough plumbing and mechanical are done, it's time for the rough electrical to go in. Then drywall. Texturing. Painting.
In most homes around my area, HVAC is usually installed before plumbing. Why? Large HVAC ducts are much harder to reroute or adjust than plumbing pipes. Plumbing is more flexible and can be run around existing ductwork without much trouble.
Most spend between $3,000 and $20,000. The average cost to rough-in plumbing for a bathroom is $6,500. However, it can range from as low as $3,000 to as much as $20,000. The final price depends on the piping material, bathroom size, labor fees, number of fixtures, and more.
Before the rough-in, the wall, floor and ceiling systems are built and left open, with no drywall installed. The plumbing rough-in begins when all the water supply and drain lines have been run through bored holes in the studs and other framing members.
Defining Rough-in Plumbing
It includes installing pipes and vents plus connecting them to provide water supply and drainage before adding fixtures. Drilling holes for certain equipment such as sump pumps, boilers & water heaters has to be done with precision.
Average Flat Rate
Some plumbing jobs are billed at a flat rate. As of 2025, the average plumber rates for larger repairs are typically between $500 to $800, while smaller jobs like repairing toilets, sinks, faucets, or bathtubs typically range from $125 to $350.
The drain-waste-vent system, also known as the sanitary system, is all of the plumbing in your home minus the water supply system.
Electrical is usually last, and always after plumbing. However, contractors cannot start on it until the home is “dried in.” This means that the home is finished enough that it will keep out wind, rain and weather in general. That's why electrical is often done in steps as other parts of the home are finished.
It's a complex process that takes time and experience to complete without issues. The best way to complete rough-in plumbing for your new home is to hire a professional plumber. It isn't recommended to tackle rough-in plumbing work as a DIY project.
Rough in plumbing means that the pipes for water supply and drainage have been installed completely, but the fixtures connecting to them have not been attached yet. So, even if you have a basement rough-in plumbing you still have to install your bathroom sink, toilet, tiles, and other bathroom fixtures.
Rough-in plumbing for new construction costs $8,000 to $12,000 or $4.50 per square foot for an average 2,000-square-foot home with 2 or 3 bathrooms. Repiping an existing home the same size runs $3,100 to $5,500 on average, or $0.40 to $2.00 per linear foot.
Whatever project you may be undertaking, keep in mind the #1 rule of general plumbing: know what you are doing. Knowing what is to be done and having a plan can help prevent costly, time-consuming problems from developing.
On a national average, you can expect to pay around $4.50 per square foot for new plumbing systems.
The plumbing rough-in is a complex process, and it takes time to do it correctly. Hiring a professional plumber to help you with this part of the construction process is vital. A typical plumbing rough-in takes between three and five days to complete.
Drywall costs $0.50 to $0.80 per square foot for materials. The labor cost to hang and finish drywall is $1.00 to $2.70 per square foot. The cost to drywall a 12' x 12' room is $580 to $1,800. The cost to drywall a 2,000 square foot house is $8,000 to $30,000.
Plumbers make a little more than HVAC Techs on average. The national average for plumbers is $55,000, and for HVAC techs it is $48,000. Some people do both, and the average salary for them is $60,000. Plumbers and HVAC technicians have comparable salaries.
For most home building projects, it's ideal for the plumbing fixtures to be installed before the electrical. During the plumbing rough-in installation, all of the water supply, drain pipes, and waste pipes are run through holes in the house's studs and framing structure.
Stage #1: Rough-In Phase (Underground)
Before any kind of plumbing installations can take place, the entire home will need to have their basement foundation established, and once this foundation is set, the rough-in plumbing installation phase can take place.