Commercial New Construction Plumbing

Restaurants and bars, retail, offices, salons, small medical and dental suites, warehouse and self-storage restrooms, and multi-tenant shell buildings are all in range. The plumbing scope on those buildings usually covers the water service and meter, a backflow assembly at the service, the sanitary and vent system, water heating or a booster, floor drains, and the fixtures.

Project size and schedule are confirmed before a bid goes out. High-rise work, hospital and lab systems, and jobs needing a larger full-time crew than we can staff get turned down up front rather than accepted and then delayed.

A landlord usually delivers a shell with a capped water stub, a sanitary stub-up, and not much else. The first useful step on a build-out is checking that what the landlord left matches what the tenant's plan needs, because a small waste stub at the back wall will not serve a kitchen at the front of the space, and a meter sized for retail will not carry a restaurant.

When the tenant space sits inside a building that is already occupied, water shutdowns, core drilling, and saw cutting get scheduled with the property manager and announced to the other tenants. Work that makes noise or takes water away from a neighbor happens in a window they agreed to.

The general contractor gets submittals on fixtures, carriers, water heaters, backflow assemblies, and interceptors before anything is ordered, and any substitution is proposed in writing rather than installed and explained later. Drawings that conflict with field conditions go back as a request for information instead of getting resolved quietly above a ceiling.

Coordination is the other half of it. Sanitary lines, duct, sprinkler mains, and electrical all want the same few inches above the ceiling grid, so sleeves, hangers, and routing get settled at the coordination meeting rather than at the wall. Pay applications, lien releases, insurance certificates, as-builts, and the operation and maintenance package are part of the job, not an afterthought at the end of it.

Drain, waste, and vent piping is filled and held before it is covered, which is the hydrostatic plumbing test the inspector witnesses, and the domestic water piping gets a plumbing pressure test held while the joints are walked. On a commercial job the general contractor and sometimes the engineer of record want to see the same test, so it is scheduled once and shown to everyone at the same time.

Inspections follow the phases: underground before the slab is poured, rough-in or top-out before the ceiling grid and drywall close it in, and trim-out once the fixtures are set. Grease interceptors and the backflow assembly at the water service are tested and documented separately, and the health department review of a food service space is its own approval rather than something the building inspector signs. The local building department sets test method and duration, so each inspection is booked with the authority for that address.

A commercial kitchen is where most of the plumbing budget goes. The grease interceptor is sized and located to the plans, the three-compartment sink, prep sinks, dish machine, and mop basin land on the grease or the sanitary side according to the drawings, and ice machines and prep sinks discharge through an air gap into a floor sink instead of a hard connection.

Hot water is the item that gets underestimated. A dish machine and a three-compartment sink together will empty a small water heater, so capacity and recovery rate are checked against the equipment schedule before the unit is ordered. Where gas piping to kitchen equipment is in the plumbing scope, it is sized for the connected load on that schedule and tested before the appliances are hooked up.