When you see a finished home or commercial building, you notice the finishes—layout, paint colors, trim, etc. What you don’t see is the work on the inside. Rough-in is like the skeleton of a new construction, remodel, or retrofit. It’s what happens before the drywall goes up and the space comes to life.
For plumbing specifically, rough-in work includes the early-stage installation of pipes, drain lines, and vents before the walls are closed. It ensures the plumbing system, including kitchen and bathroom plumbing, behind the walls and under the floor joists is properly placed, connected, and ready to support the plumbing features you do see and use every day.
The following guide provides more insight into plumbing work for rough-ins, including the differences between rough-in and finish plumbing, code considerations, and mistakes to avoid.
What Happens During Rough-In Plumbing?
During rough-in plumbing, plumbers install the following:
Water supply lines or supply pipes
Drain pipes for sink drains, toilet drains, etc.
Waste pipes or waste lines
Pipeline connections
Shutoff valves
Vent stacks
Drain traps
Cleanouts
Sewage ejector pumps
Fire sprinkler pipes, valves, and connections
Gas lines
Because professional plumbers need open access during this time, rough-in often involves coordination with the framing crew. In addition, plumbers may need to partner with electrical and HVAC rough-in teams.
Precise scheduling is required to ensure rough-in work is 100% completed before construction teams begin the next phase of work.
Rough-In vs. Finish Plumbing — What’s the Difference?
Rough-in plumbing is the hidden water pipes behind the walls, while finish plumbing is what you see—sinks, toilets, faucets, etc. Rough-in work happens in an early phase of construction. After rough-in, building inspectors ensure the work is code-compliant. Then, the next phase of work commences, which includes installing drywall and insulation. This is when the rough-in work gets covered in ceilings, beneath floors, and behind walls.
It’s only in the final construction phase when finish work happens. For plumbing, this finish work includes:
Installing plumbing fixtures, such as showers, toilets, and sinks
Installing drains and faucets
Connecting plumbing to appliances, like washing machines, water heaters, and refrigerators
Key Components Used in Rough-In Plumbing
The essential components used for rough-in plumbing include:
Pipes (PEX, copper, or PVC)
Fittings (elbows, couplings, traps, tees, wyes, and reducers)
Shutoff valves
Vent pipes
Access panels
Mounting hardware
Test caps
Common Code Considerations and Planning Tips
When completing plumbing rough-in, it’s essential to meet building code requirements. According to the International Code Council, 37 states and Washington D.C. have adopted International Plumbing Code (IPC) requirements. Other states, like Minnesota, Oregon, and California, have their own code requirements to meet.
Code compliance considerations include:
When rough-in for future fixtures includes drainage piping, a rough-in connection for a vent must be installed. Vent sizing depends on the amount of fixtures connected to it.
Horizontal drainage pipes must have a minimum slope (at least a quarter-inch per foot) to ensure proper drainage and prevent moisture buildup.
For ADA compliance, ensure rough-in locations for fixtures like sinks, toilets, and showers allow for proper clearances and reach ranges once the fixtures are installed.
If any portion of the rough-in is underground, pay close attention to requirements for bedding, backfill, and testing before the concrete is poured.
Use a pre-wall inspection checklist to ensure everything is in place and compliant before it’s covered.
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Mistakes to Avoid During Rough-In
Rough-in mistakes can be costly and cause project delays. Common mistakes to avoid during the rough-in process include:
Poor slope or alignment: Improper pipe slope leads to drainage issues and backups. Always follow code requirements for pitch to keep everything level and aligned.
Vent misplacement: Misplaced vents can cause poor system performance or traps to siphon. Ensure all vents are positioned according to code and system design.
Skipping pressure/leak tests: Never close up walls without testing for pressure and leaks.
Incorrect fixture spacing or height: Verify that fixture rough-ins match the specs and final layout. Misjudging spacing for toilets, sinks, or appliances can require tear-outs later.
Inadequate support or strapping: Pipes and ductwork need proper bracing to avoid shifts, sags, or even failure over time.
Neglecting future access: Always plan for access to cleanouts, main water shutoff valves, and key service points. Hidden or inaccessible components can turn minor issues into major headaches.
Trying to DIY the job: Rough-in plumbing lays the foundation for the structure’s entire plumbing system. DIYing the job without professional plumbing experience can cause a series of problems, from clogs or no hot water to full system failure.
How ServiceTitan Helps Plumbing Teams During Rough-In
The rough-in phase requires careful planning to avoid work revisions and keep the project on track. Plumbers also must coordinate with other contractors working on the structure including electricians, mechanical contractors, and drywall crews.
All-in-one plumbing software from ServiceTitan empowers plumbing professionals to complete jobs on time and within budget. Project tracking enables managers to stay informed on the progress of the job, as well as labor hours and materials used. And job costing software provides in-depth cost analysis broken down by project phase.
With Forms, you can create a rough-in checklist with step-by-step processes that must be followed and completed before moving on to the next phase of work. Also, ServiceTitan Mobile allows field techs and the office to stay in sync via messages or even uploaded photos of plumbing rough-in work for inspections.
