What gas piping do restaurant patio heaters and fire pits need?

Yes. Running gas to a new outdoor appliance is new gas piping. The City of Phoenix gas clearance table lists "Any new gas piping installation" as needing a permit, a city inspection and a city clearance. Scottsdale's permit guidance names outdoor gas work specifically: an "Exterior appliance natural gas or propane gas line (BBQ, pool heater, fire pit/fireplace, torches, gaslights, patio heater)" needs a plumbing permit. Other Valley cities set their own permit rules, so check with yours.

Our guide to who can install gas lines in Arizona covers the licensing side.

Add up every heater and fire feature, then add that to what's already on the meter. Section 402.2 of the 2024 International Fuel Gas Code, which Phoenix enforces, sizes pipe on the sum of the maximum input of everything it serves, assuming it all runs at once. On a cold January night, it does: every patio heater lit while the kitchen is slammed.

Each unit's rating plate lists its input in Btu per hour. At roughly 1,000 Btu per cubic foot of natural gas, each 1,000 Btu per hour of heater input adds about 1 cubic foot per hour to the restaurant's load, and a full patio adds up. That new total has to fit the pipe and the meter. Southwest Gas's tariff says "It is the customer's responsibility to notify the Utility of changes in their load requirements." Our page on whether a restaurant gas line can handle a new fryer shows how to add up the load, and our guide to a bigger Southwest Gas meter covers the utility side.

At least 12 inches for most underground gas piping, under Section 404.12. Section 404.12.1 allows 8 inches for "Individual lines to outdoor lights, grills and other appliances," but only where the installation is approved and not in a spot likely to be damaged. That allowance is written for individual lines, so plan on 12 inches for a line that feeds several heaters, and let the inspector confirm anything shallower. Several Valley cities, including Mesa, Gilbert, Queen Creek, Surprise and Tolleson, deleted the 8-inch allowance; the gas pipe burial depth by city page compares them.

Plastic gas pipe is common outdoors, with limits. Section 404.17.1 says "Plastic pipe shall be installed outdoors underground only," and not under a building or slab. Outdoor patio, walkway and driveway slabs are an exception, as long as the burial depth is met. Plastic pipe also needs a yellow insulated copper tracer wire so the line can be found later.

That matters because Southwest Gas won't find it for you. Its safety page warns that "customer buried piping can't be located by calling 811." Keep a drawing of where the patio line runs, especially before anyone digs for planters, footings or new pavers. Our page on why underground gas lines at businesses fail covers what happens to buried lines over time.

### Who maintains the patio gas line?

The property side does, not the utility. Southwest Gas's buried piping brochure says customer buried piping includes "piping to outdoor appliances." Buried lines can corrode or get damaged by digging, so have an old patio line checked for leaks when you renovate. In a leased space, the lease decides whether the landlord or the restaurant pays for that line. Our page on who owns the gas piping in a strip center sorts out the split.

Plastic pipe has its own details at the ends. Section 404.17.2 requires transition fittings conforming to ASTM D2513 Category I or ASTM F1973 where plastic meets metal underground, and the tracer wire needs access or has to come above ground at each end, so a locator can find the line later.

It depends on whether the unit moves.

Section 630.1 requires infrared radiant heaters to be listed to ANSI Z83.19 or Z83.20 and installed per the manufacturer's instructions. Section 635.1 requires permanently fixed-in-place outdoor decorative appliances to be listed to ANSI Z21.97. The manual sets the clearances to ceilings, umbrellas, awnings and walls, so read it before choosing where a heater hangs.

### Where do the shutoff valves go?

Near each unit. Section 409.5.1 puts each appliance's shutoff within 6 feet of it, upstream of the union, connector or quick disconnect it serves, with access. Section 409.5.3 allows the shutoffs at a manifold instead, within 50 feet of the appliances, with ready access and each one permanently identified. For a patio with a dozen heaters, a labeled manifold can make closing time and service much easier.

A few things save trouble later:

1. 1Count the load before buying heaters. The pipe and meter set the ceiling.
2. 2Lay out the line with the patio design. Trenching after the pavers go down means tearing them back up.
3. 3Label every shutoff so staff can turn off one heater without killing the patio.
4. 4Test the new piping. New gas piping is pressure tested before it's covered, at not less than 1-1/2 times its working pressure and never under 3 psig, per Section 406.4.1. Our guide to how a gas line pressure test works walks through it.
5. 5Know the leak signs. If anyone smells gas on the patio, don't light or switch anything. Move people away, then call 911 and Southwest Gas at 877-860-6020 from a safe place.

HQ Plumbing & Air runs commercial gas lines to patio heaters, fire pits and fire tables for restaurants across the Phoenix area, from load sizing and trenching to permits and pressure tests. We're licensed and insured, and you get a free estimate with the price up front. For a single home grill or fire pit, see our page on running a natural gas line to a grill.

Plan the gas with the patio, not after it.