Garage Construction Project

2026-05-19 - Site Visit - Brian McJames Plumbing Utility Trench Estimate

9 min read

Purpose

On-site walk-around with Brian McJames (“BM Plumbing”) to evaluate the house-to-garage utility trench scope and gather information for a formal estimate. New trench will carry hard water, soft water, natural gas, and sewer. This is the follow-up to the 2026-05-11 voicemail that came back as a site-visit appointment.

Weather

Weather:

Notes

Scope Walked

  • Four utilities in one trench: hard water, soft water, natural gas, sewer
  • Brian evaluated routing and tap points on-site
  • Open trench timing relative to driveway pour was a known concern coming in (see 2026-05-11 - Call - Terry Utility Trench Timing) — to be reflected in the formal estimate

Defined Scope of Work — Trench Only

Owner’s directive for Brian’s quote: complete the trench and stub off the ends only. This is the critical-path step holding up the driveway pour bottleneck, so finishing the trench is the priority — everything else can come later.

  • In scope: Excavate trench, run sewer + natural gas + hard water + soft water lines from house to garage, stub off both ends so the driveway can be poured over a closed/buried trench
  • Out of scope (this engagement): Boiler installation, bathroom rough-in, kitchen rough-in, final tie-ins to fixtures, interior gas-appliance connections
  • Owner reserves the right to revisit: May bring Brian back for specific tasks later; open to expert input but defaulting to DIY for non-trench work

Boiler & Interior Rough-In — Offered, Declined for Now

Brian offered to take on additional scope beyond the trench:

  • Boiler installation (Navien combi — see boiler recommendation below)
  • Bathroom rough-in plumbing
  • Kitchen rough-in plumbing

Owner declined the expansion for now — preference is to DIY as much as possible (consistent with the project’s DIY-first philosophy — see root CLAUDE.md). Stance: “always open to listen to experts,” so this isn’t permanent — owner may re-engage Brian for specific later-phase work if DIY proves impractical.

Licensed-Plumber Scope — Resolved

Brian’s professional opinion: no plumbing certification is required for this work. Specifically:

  • Running utility lines (sewer, natural gas, hard/soft water) between two buildings on the same property owned by the homeowner can be done as owner-DIY
  • Only requirement is pulling the appropriate permits — owner can pull these directly
  • This closes the open question from 2026-05-11 - Call - Brian McJames Plumbing (#2: “Which portions require a licensed plumber?“)

Implication: Owner has a real DIY path for the entire utility trench + interior rough-in + boiler install if desired. Current decision is to hire Brian for the trench specifically to keep the driveway pour on schedule (DIY trench excavation + multi-utility install would take longer than the bottleneck allows), and to revisit DIY vs. hire for each subsequent phase.

Natural Gas Line — Brian’s Proposed Approach

  • Plans to run a 1½″ gas line from a tap near-direct off the gas meter to the garage
    • Generous over the ¾″ minimum spec’d in Gas Line Requirements (which only sizes for the generator alone at ≤25 ft)
    • 1½″ trunk sizes for whole-property simultaneous load (boiler + generator + house gas appliances) and provides headroom for a future permanent standby generator (200–300 ft³/hr per Future Upgrade Path)
    • Near-direct-from-meter routing means generator startup won’t sag pressure to existing house appliances
  • Meter upsize discussed. Existing meter is a Honeywell/Elster AC-250 rated 250 CFH (~250 kBTU/hr) — see Existing Utility Service Assessment Nov 2025. Combined load (generator ~120 kBTU/hr + boiler + house appliances) likely exceeds 250 kBTU/hr in cold-weather peaks. Brian acknowledged this and agrees DTE meter/regulator upsize coordination will be part of the work.
  • Generator gas consumption info sent to Brian after the visit (per his request): Predator 11,500W tri-fuel at ~120 ft³/hr (~120,000 BTU/hr) at full natural-gas load. Source: Backup Generator Plan.

Boiler Brand Recommendation

  • Brian strongly recommended Navien during the walk-around. Stated he doesn’t like to install anything else — exclusively works with Navien for combi/tankless installs. Implies deep operational familiarity (parts inventory, error codes, install procedures, warranty workflow) — useful if owner re-engages Brian for the boiler scope later.
  • Advice given as expert opinion, not as part of Brian’s quoted scope (boiler install was offered but declined — see above)
  • Brand recommendation validates the existing pick. Boiler Selection already evaluated five options (Navien NCB-E, Rinnai i120CN, Bosch 8000iF, dual Navien NHB+NPE, Navien NHB+indirect) and recommended the Navien NCB-E 150 as the best fit. Brian’s independent recommendation aligns with the existing design decision.
  • Specific model still TBD from Brian — when his quote arrives (if boiler is later added to scope) or when he’s consulted, verify whether he means the NCB-E 150 specifically or a current-production successor (NCB-H, NFC, or other Navien series). Update the existing pick if it has been superseded.

Sewer / Water

  • Routing details captured during walk-around; specific tap points will be itemized in the formal estimate
  • See House-to-Garage Utility Routing Strategy for the existing slab conduit terminations the trench needs to meet
  • Both lines stubbed at each end (per defined scope above) — final interior tie-ins are owner-DIY or future-engagement

Tracer / Locator Wire — Follow-Up to Raise with Brian

Not discussed during the 2026-05-19 visit. Added as a follow-up scope item to raise before the trench is closed — must be installed after pipes are laid but before backfill, so the open-trench window is the only practical opportunity.

What it is: Solid copper wire run alongside (or just above) each non-metallic utility, terminated at accessible points above grade. A utility locator clips to the wire, energizes it with a signal, and a receiver traces the path from the surface. Without it, PE gas, PEX water, and PVC sewer are essentially invisible to standard locators — future trench work would be guessing with a probe.

Recommended spec for all four utilities:

  • 12 AWG solid copper, HDPE or HMWPE insulated (the insulation matters — standard THHN degrades underground)
  • Color-coded per service: yellow (gas), blue (potable / hard water), purple (soft water), green (sewer)
  • One wire per utility, run directly on or just above each pipe
  • Splices: waterproof direct-bury connectors only (DBR/DBY gel-filled). Never wire nuts.
  • Terminations must be accessible above grade — typically brought up inside the gas riser, water shutoff valve box, or a dedicated locator station. A buried wire with no surface access is useless.

Code note: Tracer wire on buried gas is required by NFPA 54 and most state amendments — Brian’s gas sub should already plan it. Water and sewer are owner’s choice but the same logic applies.

Scope split decision (owner’s preference):

  • Gas tracer: Brian’s scope. Part of the certified gas install — don’t have a third party touching it.
  • Water (hard + soft) and sewer tracer: ask Brian to include in quote. Material is cheap (~$50–100 total), labor is minimal with the trench already open. If Brian excludes them to keep the quote lean, owner can DIY before backfill — no license or certification needed for water/sewer tracer wire between two owner-occupied buildings on the same property.
  • DIY fallback timing: trench-open / pre-backfill window only. Owner needs to coordinate with Brian to be on-site during that window if DIY’ing any of the lines.

Decisions

  • Brian’s scope is trench + stub-off only. Boiler and bathroom/kitchen rough-in were offered by Brian and declined for now — owner defaulting to DIY for those phases.
  • DIY path confirmed feasible. Brian states no plumbing certification is required for utility lines between two owner-occupied buildings on the same property — only permits. Owner currently choosing to hire Brian for the trench specifically to keep the driveway-pour critical path on schedule, not because the work requires a licensed plumber.
  • Final estimate pending — pricing and timing decisions deferred until Brian’s formal written quote is in hand.

Action Items

  • Brian to send formal estimate (trench + stub-off scope only) — owner:: Brian
  • Reply to Brian: ask him to include tracer/locator wire on all four lines (12 AWG solid copper, HDPE/HMWPE insulated, color-coded, terminated above grade) in the quote — gas tracer required per NFPA 54 anyway; water/sewer tracer is cheap to add while trench is open. If he excludes water/sewer, owner will DIY before backfill. — owner:: Owner
  • Owner to send generator natural-gas consumption details (120 ft³/hr / 120 kBTU/hr) to Brian — owner:: Owner
  • When estimate arrives: update Backup Generator Plan gas line section with the 1½″ trunk + meter-upsize plan (currently shows ¾″ minimum only) — owner:: Owner — stage:: 6
  • If/when boiler install scope is reopened with Brian: confirm specific Navien model he installs (NCB-E 150 vs. current successor); update Boiler Selection if model has changed — owner:: Owner — stage:: 6
  • Identify required permits for owner-pulled trench + future interior plumbing DIY (local municipal building department) — owner:: Owner — stage:: 6
  • Coordinate DTE meter/regulator load study (per the existing required action in Existing Utility Service Assessment Nov 2025); confirm whether Brian or owner initiates that contact — owner:: TBD — stage:: 6
  • Add Brian to Brian McJames Plumbing dedicated contractor record (done as part of this visit’s follow-up) — owner:: Owner
  • Update Plumbing Contractors candidate status: voicemail → site-visited, estimate pending — owner:: Owner

Timeline Impact

  • Trench is the current critical-path bottleneck for the driveway pour. Brian’s quote and availability directly drive when All American Concrete can be scheduled.
  • No timeline change yet — estimate pending. Once Brian’s quote and start date are confirmed, update Timeline with utility-trench scheduling and the resulting driveway-pour window.

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