The New Construction with a Hot Water Heater in the Garage
You are doing a pre-drywall and final inspection on a new-construction single-family home. In the attached two-car garage, the builder has installed a 50-gallon gas-fired water heater on a platform about 18 inches above the floor, with a flexible gas connector, a draft hood, and a single-wall metal flue that rises about 6 feet and turns horizontally through the garage wall to the exterior. The garage is not conditioned and has a standard 7-foot overhead door. The water heater's T&P valve discharges through a copper pipe that runs down the platform and terminates about 6 inches above the garage floor. The furnace is in a closet inside the house, and the garage ceiling is drywalled. The builder says 'it all passed the rough-in inspection.' Your agreement covers visible plumbing, gas, and mechanical components and excludes code compliance determinations.
1. Identify the safety-related concerns you can observe with the water heater installation and explain why each matters.
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Several concerns are visible and worth reporting even though you do not make code determinations:
Flue termination through the garage wall - a single-wall metal flue that turns horizontally and exits through a combustible wall requires proper clearances and a listed thimble/vent assembly. If the flue passes through the wall without a listed clearance assembly, that is a fire hazard. Report the visible condition and recommend evaluation by a licensed HVAC contractor.
Draft hood and flue in an unconditioned garage - a draft hood relies on a stable pressure environment. In a garage with a large overhead door, opening the door can create a pressure swing that spills flue gases. Report the configuration and recommend a qualified HVAC contractor verify draft and spillage.
T&P discharge termination - the T&P relief valve discharge should terminate in a manner that prevents scalding and is visible to the occupant. Terminating 6 inches above the floor is common, but confirm the pipe is not threaded/capped at the end (which would block relief) and that it is not reduced in size. Report what you see.
Flexible gas connector - confirm it is not passing through the cabinet or wall and is not kinked. Report visible deficiencies.
Platform height - an 18-inch platform in a garage is intended to keep the ignition source above possible gasoline fumes. Report the height and note that the installation should be verified against the manufacturer's instructions and local requirements.
2. The builder cites a passed rough-in inspection. How should that affect your report, and what is the correct professional posture?
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A passed rough-in inspection is not evidence that the final installation is correct, and it does not transfer the inspector's duty to you. Rough-in inspections occur before drywall and before final connections; the flue termination, the T&P discharge, and the gas connector may have been completed or altered afterward. Municipal inspectors also inspect to the locally adopted code at the time of permit, which may differ from current standards or manufacturer instructions.
Your posture should be:
- Report what you observed, independent of the permit status.
- Do not opine on code compliance - your agreement excludes it, and you are not the authority of record.
- Recommend that the buyer ask the builder for the final inspection sign-off and the manufacturer's installation instructions, and that a licensed HVAC contractor verify draft, spillage, and flue clearances.
- Document the builder's statement in your report as a statement made, not as a finding.
The exam tests whether you can resist the social pressure of 'it passed inspection' and still report visible safety concerns. The correct answer is to report, disclaim code authority, and refer.