Mechanical Room

Location & Layout

Preferred location:
Clearances: maintain manufacturer service clearances around all equipment.
Floor: confirm PEX routing under walls; avoid PEX under anchor points.
2025-10-13 contract includes enclosed stair with small mechanical closet; coordinate final wall dimensions before framing to ensure equipment fits.

Critical Dependencies: Boiler Operation Timeline

Boiler installation and operation require sequential completion of multiple systems with significant lead times. Do not expect boiler operation until late December at earliest; early January is more realistic.

Lead Time Items (Must Start Immediately)

Electrical Service Installation ⏱️ 2-4 weeks
- Licensed electrician pulls 200A wire through existing underground conduit
- 200A panel installation in mechanical room
- 100A feed from house panel
- Meter installation and energization
- Permit and inspection approval
- Action: Contact licensed electrician immediately for quote and scheduling
Natural Gas Service Installation ⏱️ 2-4 weeks
- Licensed gas fitter pulls PE pipe through existing underground conduit
- Underground burial and pressure testing
- Gas line termination and inspection
- Action: Contact licensed gas fitter immediately for quote and scheduling
Boiler Venting Route ⏱️ Must be confirmed before framing (Stage 3)
- Boiler manufacturer specifications determine vent route
- Flue vent penetration through wall/roof
- Proper termination clearances per code
- Must be planned during Stage 3 framing
- Action: Review boiler model vent requirements; confirm route before wall framing

Sequential Dependencies

MECHANICAL ROOM FRAME (Stage 3)
        ↓
  Electrical Service Install (licensed electrician)
  AND
  Gas Service Install (licensed gas fitter)
        ↓
  Boiler Installation (professional)
        ↓
  System Commissioning
        ↓
  RADIANT HEAT OPERATIONAL

Critical Path: All three installations (framing, electrical, gas) must complete before boiler can operate. Any delay cascades.

Notes on Winter Timeline

High-demand season (Dec 1 - Jan 31): Electrical and gas contractors typically fully booked
Expect 2-4 week scheduling delays during winter months
Best-case scenario: Boiler operational mid-December
Realistic scenario: Late December to mid-January
Spring scheduling (Mar-Apr): Faster contractor availability if winter operation not critical

Insulation Sequencing Impact

Important: Operating boiler in uninsulated garage is inefficient and wastes fuel. Before or concurrent with boiler startup, complete:

Mechanical room: Full insulation + drywall (should be done before boiler installation anyway)
Perimeter wall air-sealing minimum (seal around penetrations, rim joists)
This dramatically improves boiler efficiency and working comfort

See: Winter Construction Strategy for detailed timing analysis and alternative strategies.

Equipment & Services

Radiant heat boiler (NG): flue/combustion air, condensate drain, gas, electric.
Radiant manifolds: supply/return placement, isolation valves, purge points.
Electrical service/panel: ampacity, working clearances, feeder/conduit path.
Mini-split provisions: line-set sleeves, condensate drain, outdoor unit disconnect.
Domestic water/sewer rough-ins (future bath/laundry upstairs).
Low-voltage: network cabinet, conduit to house.

Penetrations & Rough-Ins

Gas: sleeve and shutoff location.
Flue/vent: route and termination per code (sidewall/roof; clearances).
Condensate: dedicated drain to approved location with trap/neutralizer if required.
Condensate for mini-split (if indoor head nearby): route with slope.

Water Main Rough-In & Future Flo Reservation

The incoming water main enters the mechanical closet, passes through the softener (if installed), and branches to the boiler/DHW and any other garage fixtures. Lay out the rough-in to accommodate a future Moen Flo (or equivalent) smart shutoff valve if the loft is later converted to a rental apartment (see Future: Second Flo for Loft Apartment Conversion).

Rough-in requirements (do this during plumbing rough-in, not later):

Reserve ~10–12” of straight copper (¾” or 1”, matching the main size) on the incoming water main, inside the closet, before any branches so a future Flo protects the entire garage
Install isolation ball valves upstream and downstream of the reserved section so future cut-in doesn’t require a house-wide shutoff
Place a 120V duplex outlet within 4 ft of the reserved section (Flo needs line power)
Keep the reserved section accessible — not buried behind the boiler, softener, or wall framing
Leak detection pucks in the closet don’t need any rough-in accommodation — they’re wireless and battery-powered

Today’s install is pucks only (under boiler, manifold, softener). The house-side Flo covers the garage for catastrophic bursts. A second Flo is a future upgrade triggered by the apartment conversion, not a near-term purchase.

Electrical

Dedicated circuits: boiler, pumps, mini-split outdoor unit, server rack, lighting.
Receptacles: utility outlets at work height; GFCI where required.

Actions

Freeze mechanical room location and wall layout — completed pre-pour Oct 2025 — stage:: 2
Mark PEX-free zones for wall anchors and penetrations — completed pre-pour Oct 2025 — stage:: 2
Place sleeves for gas, condensate, line-sets, and low-voltage before pour/framing as needed — completed pre-pour Oct 2025 — stage:: 2
Confirm boiler vent route and termination location. — stage:: 4
Coordinate panel location and service entrance route. — stage:: 3
Update one-line electrical and hydronic schematics — completed pre-pour Oct 2025 — stage:: 2
Confirm PEX tube depth near mechanical room walls; select appropriate anchor length for treated 2x4 sill to slab — completed pre-pour Oct 2025 — stage:: 2

After Build / Commissioning

Set electrical service/meter and energize panel; label circuits — stage:: 6
Install boiler and manifolds; commission radiant heat (purge, venting, leak check) — order:: Boiler and Radiant Order — stage:: 6

Procurement

Order: Boiler and Radiant Order
Index: Orders Index

Garage Construction Project

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