What plumbing to check before buying a commercial building?

The City of Phoenix says property owners are "responsible for maintaining and repairing the sewer and water lines that run through their property" and connect to the city mains. That makes a buried line your problem the day you close. A camera inspection is the only way to see it; see should I scope the sewer line before buying and how to read the coded report.

Phoenix City Code 37-144 says the customer's water system "starts at the point of service delivery from the public potable water system" and includes all water piping. Everything past the meter is yours. Ask for water bills going back a year or more and look for spikes. A quick meter check with every fixture off shows a hidden leak; here is how to do a water meter leak test.

A backflow assembly protects the city's water from your building's piping. Phoenix City Code 37-144 requires the customer to test each assembly at least once a year (the Director can require more), to have a certified tester do it, and to keep test records for at least three years from the date the copy went to the city. The city's own guideline says installing, altering or replacing any backflow assembly needs a plumbing permit. So ask for:

• the location and type of every assembly
• the last test report and the city's record that it was received
• permits for any that were replaced

More in backflow assembly registration in Phoenix. If the use will change, read change of use and backflow.

Phoenix City Code section 28-12 says interceptors must be installed and operated by laundries, food service establishments, service stations, auto repair shops, carwashes, commissaries and other facilities when the Director determines they are necessary for handling liquid wastes with excessive grease or oil. Section 28-15 sets pump-out rules. For gravity interceptors that means a full pump-out whenever buildup reaches 25 percent of liquid capacity and at least every 12 months, and at least every three months for food service establishments that capture FOG, unless the Director grants a variance. Ask where the interceptor is, and ask for its pump-out records. See grease trap versus grease interceptor and pumping records in Phoenix.

Write down each heater's type, fuel, capacity and age from the nameplate, and ask for the permit history. Then match it to the tenant's hot water use. Our guide to commercial water heater types helps. If the building has a recirculating hot water loop, CDC's potable water guidance says to store hot water above 140 degrees Fahrenheit and keep circulating hot water from falling below 120.

The 2024 International Plumbing Code, Section 403.1, says fixtures must be provided in the minimum number in Table 403.1 "based on the actual use of the building or space," with occupants determined under the International Building Code. A space built as an office may not have enough fixtures for a restaurant. Phoenix's code page lists both the 2024 IPC and the 2024 Uniform Plumbing Code among its adopted codes, so ask plan review which fixture table governs your use. For accessibility, see ADA plumbing for a commercial restroom.

Phoenix Planning and Development lets you look up permits and inspection history by address online, along with Certificate of Occupancy records. Pull them for the plumbing permits, and compare them with what you see in the building. Work with no permit on file is a question for the seller.

HQ does commercial plumbing and sewer camera inspections. We are licensed and insured, and we give free estimates with upfront pricing on any repair the inspection turns up. For an urgent problem in a building you already own, 24/7 emergency service is available.