Title: Plumbing subcontractor guide | Cercha
Description: Compare plumbing subcontractors by underground scope, tests, NC licenses, fixture handoffs, inspection records, and callback plans.
Canonical: https://cercha.pages.dev/trades/plumbing/
# Plumbing subcontractors: from underground to final
Residential trade guide
You need the piping, tests, and fixture connections covered without a gap between visits. Define underground work and finish responsibilities before you accept the bid.
## Plumbing subcontractor scope from underground to final
Compare plumbing subcontractors by the complete sequence of work you want them to carry. Request separate descriptions for underground piping, concealed [rough-in](/glossary/#rough-in), fixture installation, tests, and corrections. Write the limits of each service connection into the proposal before you compare prices.
### Set the scope before the first excavation
NC defines plumbing around the pipes, fixtures, and related apparatus that supply water and convey sewage or waste ([Read G.S. 87-21](https://www.ncleg.gov/EnactedLegislation/Statutes/HTML/BySection/Chapter_87/GS_87-21.html)). For a new home, mark water distribution, drain-waste-vent work, water heating, fixtures, and exterior connections on the scope sheet.
For a remodel, identify retained piping and proposed relocations. Ask how the bidder will inspect accessible existing conditions and price discoveries after opening walls. Agree on shutdown arrangements, protection of occupied rooms, and who repairs surfaces after the plumbing work.
Do not write only “complete plumbing” beside a fixture allowance. Name who buys each fixture, checks its installation information, supplies the rough components, and approves substitutions. Include the owner-supplied items in that same discussion. Use the [PEX-vs-CPVC guide](/guides/pex-vs-cpvc/) to review the complete piping system with the plumber before rough-in.
### Coordinate underground, rough-in, and finish visits
The homebuilding phase overview groups plumbing with rough-ins and distinguishes foundation, interior finishes, and closeout ([Read the project overview](https://www.nahb.org/-/media/NAHB/advocacy/docs/industry-issues/disaster-resources/home-building-overview.pdf?rev=6f76493d1a3e493fb717f52f0fa47d7e)). Use those phases to build a project-specific plan, then confirm it with the superintendent and plumber.
Before concrete or backfill, agree on access for inspection and the party releasing the area. Before walls close, coordinate with framing, electrical, HVAC, and insulation. Before fixtures arrive, confirm the tile, cabinet, and [countertop interfaces](/trades/countertops/). Assign shower waterproofing and roof-penetration sealing explicitly.
Raleigh requires concealed plumbing to be ready for rough-in checks and underground work to remain available before covering. At final, plumbing must be complete and leak-free, with water pressurized ([Review Raleigh's stages](https://raleighnc.gov/permits/services/residential-inspections)). Ask your inspector which inspections apply to the actual permit.
### Verify the contractor and response arrangements
NC Class II plumbing licensing covers single-family detached residential dwellings. Class I covers systems in all structures. The statute also limits a license to its authorized trade ([Check G.S. 87-21(b)](https://www.ncleg.gov/EnactedLegislation/Statutes/HTML/BySection/Chapter_87/GS_87-21.html)). Confirm the contracting entity and scope with the plumbing and heating board.
Request a current [certificate of insurance (COI)](/guides/check-subcontractor-insurance/), similar-project references, and a named supervisor. Ask how the sub staffs each visit and handles an unfinished connection when the next trade arrives. Get written workmanship warranty terms and a leak-response contact. Check current coverage directly with the employer or insurer.
Ask a reference builder about one problem job. Find out who answered, what was recorded, and how completion was confirmed. Request an example test record and correction log rather than relying on a general promise about service.
### Inspect the evidence behind the finish photo
Raleigh documents untested piping, poor underground bedding, reverse-pitched vents, and untested shower membranes among plumbing rejection reasons ([See the local defect list](https://raleighnc.gov/permits/services/failing-inspection-residential-projects)). Use those subjects to guide your reference questions and pre-cover documentation request.
Ask for dated photos of underground work, supported rough piping, protected penetrations, and completed water-heater connections. Pair the photos with test and inspection records. Ask which plumber performed the work and which other trade owned the adjacent waterproofing or finish. A finished bathroom belongs in the portfolio alongside this record.
### Keep residential fire sprinklers under a named specialist
Do not assume every plumbing contractor designs or installs residential fire-sprinkler systems. NC's plumbing and heating board lists separate fire-sprinkler credentials, including a residential installation license. Ask the board to confirm design and installation authority for the proposed system. [Board applicant information](https://nclicensing.org/applicant-information/)
Name the sprinkler contractor and approved design owner before water-service work is released. Ask who confirms supply information, service size, metering or backflow arrangements, and any connection shared with domestic plumbing. Coordinate underground access with [excavation](/trades/excavation/) and ceiling routes with [framing](/trades/framing/). Assign testing, required inspections, owner records, and repairs before [drywall](/trades/drywall/) conceals the system.
### Give the GC one coordination record
Name the GC contact and plumbing supervisor for underground, rough-in, finish, and correction visits. Record start conditions, inspection requests, changes, and the party releasing each area. Use Raleigh's inspection list as a local example, then confirm your permit's requirements. [Inspection stages](https://raleighnc.gov/permits/services/residential-inspections)
Use the [shower ownership guide](/guides/who-owns-the-shower/) to assign drain, membrane, testing, and concealment responsibilities with [tile](/trades/tile/). Have [cabinets](/trades/cabinets/) confirm fixture locations before rough-in and reconnects. Route changed selections through the GC before the crew moves piping or reserves another visit.
## For plumbing subs and crews
Show builders how you manage the gaps between visits. Identify your house types, remodel scopes, service area, and available stages in your introduction. Offer a comparable project with a short explanation of your responsibility.
Prepare a selection checklist for the GC. Identify each fixture decision you need, the information still missing, and the date you need an answer. Send that list before the crew arrives. Record approved changes and the effect on the next visit in writing.
Build a portfolio that pairs rough and finished views of the same project. Caption the underground scope, testing stage, fixture package, and your company's role. Keep inspection records available for direct review. Ask a builder reference to discuss coordination and correction handling as well as appearance.
Keep a fixture-selection register that connects approved rough locations with the final purchased models. Have the [plumbing house or showroom](/suppliers/plumbing/) flag missing selections before delivery. At handover, reconcile completed connections, outstanding parts, inspection records, and the contact responsible for a reported leak.
This page maps plumbing to NAICS 238220 and MasterFormat Division 22 for reference. Those categories do not replace the license check. [NAICS manual](https://www.census.gov/naics/reference_files_tools/2022_NAICS_Manual.pdf), [division reference](https://theconstructionstandard.com/guides/masterformat-groups.pdf).
## Examples from the field
*Illustrative examples, not member stories*
### Underground piping before a slab (illustrative)
Your plumbing crew completes underground work before concrete placement. Keep the area accessible for the required inspection and identify who releases it for covering.
### Shower waterproofing boundary (illustrative)
Your shower scope involves the plumber and tile installer. Record ownership of the drain interface, waterproofing, testing, and acceptance before tile conceals the work.
### Fixture selection changed before finish (illustrative)
Your approved faucet or sink changes after rough-in. Reconcile the purchased model with the fixture register and record any approved location or connection changes.
## Where Cercha fits
Review plumbing members' named projects in Portfolio and their builder endorsements. Use Search by trade, ZIP code, and radius, then Messages to clarify your project scope. Confirm tests, current credentials, and actual availability directly.
## Related trades and suppliers
- [Hiring an excavation subcontractor for sitework]()
- [Hiring a residential framing subcontractor]()
- [Hiring a concrete and foundation subcontractor]()
- [Cabinet installers for builders]()
- [Countertop fabricators and installers]()
- [Tile subcontractors for wet areas and floors]()
- [Insulation subcontractors: assemblies and pre-cover proof]()
- [Drywall subcontractors: hang and finish]()
- [Plumbing supply houses for rough-in and trim]()
## Questions
### At which stage should the plumber join a new-build project?
Bring the plumber in before foundation and fixture decisions are released. Separate underground, rough-in, and finish responsibilities in the agreed scope.
### Does the plumbing scope cover below-slab and underground pipework?
Only if the written scope includes it. Name the endpoints and assign excavation, bedding, testing, backfill, and utility interfaces explicitly.
### Can rough plumbing proceed before the final fixtures are chosen?
Set the rough-in-dependent selections first. Have the plumber identify which remaining choices can wait, and record any allowance for later changes.
### Which party arranges the plumbing inspections?
The party named in your subcontract arranges them. Assign test preparation, inspection requests, and correction visits, then confirm the permit-specific list.
### How does the plumber coordinate with the GC?
Use a named GC contact and plumbing supervisor. Schedule underground, rough-in, finish, inspection, and correction visits against written release conditions. Route changes through the GC. Record tile, cabinet, and countertop handoffs before the next visit.
## Build your connections
[Ask about the beta]()
## Sources
1. N.C. Gen. Stat. § 87-21. https://www.ncleg.gov/EnactedLegislation/Statutes/HTML/BySection/Chapter_87/GS_87-21.html
2. City of Raleigh. (2026, October 12). *Residential Inspections*. https://raleighnc.gov/permits/services/residential-inspections
3. City of Raleigh. (2026, February 11). *Failing an Inspection: Residential Projects*. https://raleighnc.gov/permits/services/failing-inspection-residential-projects
4. Grand County Builders’ Association. (2021, May 18). *Overview to the custom homebuilding process*. https://www.nahb.org/-/media/NAHB/advocacy/docs/industry-issues/disaster-resources/home-building-overview.pdf?rev=6f76493d1a3e493fb717f52f0fa47d7e
5. Executive Office of the President, Office of Management and Budget. (2022). *North American Industry Classification System: United States, 2022*. https://www.census.gov/naics/reference_files_tools/2022_NAICS_Manual.pdf
6. The Construction Standard. (n.d.). *MasterFormat Groups, Subgroups, and Divisions*. Retrieved October 14, 2026, from https://theconstructionstandard.com/guides/masterformat-groups.pdf
7. North Carolina State Board of Examiners of Plumbing, Heating, and Fire Sprinkler Contractors. (n.d.). *Applicant Information*. Retrieved October 14, 2026, from https://nclicensing.org/applicant-information/