Choosing Plumbing Subcontractors

Think About:

• Licensed plumber with residential or high-end experience

• Do they include material supply or expect GC to supply?

• Coordination with:

  • Foundation (for sleeves + penetrations)

  • Framing (for drilling & blocking)

  • HVAC (for vents & shared chases)

  • Electrical (for grounding bond locations)

• Ability to handle inspections in phases

• Warranty and responsiveness after close-out

Subcontractors to Select:

• Plumbing rough-in subcontractor (primary)

• Gas line installation subcontractor (sometimes separate)

• Venting specialist (if code requires)

• Fire-stopping installer (if not included)

• Water filtration system installer (if included)

• Specialty subcontractors (steam showers, spas, recirculation pumps)

Choose a plumber who understands inspection timing and design intent.

Choosing Plumbing Materials

Think About:

• Approved materials per code and engineer requirements

• Noise reduction in walls (important in custom homes)

• Long-term serviceability — access panels and shutoffs

• Temperature and pressure ratings for fixtures and systems

• Gas code compliance + future appliance changes

Materials to Select (as applicable):

Supply Lines:

• PEX A or PEX B w/ expansion fittings

• Copper type L or M (verify code + water conditions)

• Manifold systems for isolation

Waste / Vent Lines:

• ABS or PVC pipe + solvent welds

• Cast iron for noise reduction (stack areas)

Valves & Controls:

• Main shutoff valve

• PRV (pressure reducing valve)

• Recirculation pump system (optional for efficiency)

• Backflow preventers

Fixtures + Trims:

• Sinks, faucets, toilets, tubs

• Shower valves + diverters (specs through interior design)

• Specialty luxury fixtures (body sprays, thermostatic valves)

Special Systems:

• Water filtration / softening

• Sump systems

• Sewage ejector (if plumbing below sewer line)

• Gas line fittings (CSST or black iron)

Everything must match design selections from interior design & client approval.

Choosing Tools, Equipment & Rentals

Think About:

• Cutting/drilling systems that reduce noise + structural damage

• Combined trench work w/ earthwork subcontractor

• High-pressure testing equipment for inspections

Tools & Equipment to Select:

• Pipe cutters & expansion tools (PEX)

• Torch kits (if copper)

• Hole saws / drills w/ framing coordination

• Laser level for drain slope

• Test plugs & pressure testing setup

• Gas leak detection tool

• Temporary heaters for cold weather testing

• Sawzall for retrofit adjustments

Missing one testing part can cause a failed inspection.

Choosing Vendors & Supply Sources

Think About:

• Fixture lead times — many require 8–16 weeks

• Availability of matching trims to interior design package

• Local plumbing shop vs national distributor pricing

• Tech support for high-end systems

Vendor Types to Evaluate:

• Plumbing supply house (rough materials)

• Fixture supply showroom (customer selection support)

• Gas piping supply vendor

• Test equipment rental provider

• Water conditioning + filtration supplier

Rough-in must support future finish selections — confirm compatibility early.

Choosing Inspections & Documentation Support

Think About:

• Plumbing typically has 2–3 inspections (underground, rough, final)

• Must document pipe type, slope, and vent routing

• Photo evidence of all covered piping + labeling

Support Partners to Select:

• Inspector scheduling coordinator (internal or sub)

• Photographer or PM for documentation

• Pressure test witness (inspector or tech)

• Engineer if redesign needed for structural conflicts

Documentation = protection when walls close up

Thank you for completing this Session!

Home Building Master Class | The Contractor Checklist

Video Explanation

www.thecontractorchecklist.com