New Gas Line

Are you interested in getting a new gas line? If you live in Fayetteville, NC, here’s a general overview of the process we will go through.

This process is specific to Fayetteville, NC. It will be roughly the same for the rest of NC, but other states likely have different inspection requirements.

A complicated gas meter/manifold setup


Lets say I arrive on site, and you want a gas line run to your fireplace. You have a gas logs technician coming next week, so you just need a gas line to the fireplace. You point out that there is a gas stove 5 ft away from the fireplace, so this job should be easy, right? Luckily, the homeowner hired a licensed plumber who knows to ask questions and perform a full evaluation on the gas system before installing this gas line.

I start by asking how many appliances are on gas. The kitchen stove and the furnace in the attic are the only 2 gas appliances. I then look at the gas meter. This gas meter has a white face, which means low pressure (0.5 psi). I then go into the crawlspace. I see a 3/4″ black iron gas line run 20 feet across the crawlspace. Then there is a tee. Off the side of this tee a 1/2″ black iron gas line runs to the stove. The main gas line continues in 3/4″ black iron to the attic, where the furnace is.

a tee on black iron, with a valve in each direction

The plumber knows what the btu requirements are for the stove, furnace, and the new proposed fireplace. He looks at his gas pressure table. The 3/4 gas line should be able to handle both the stove and the fireplace! We can’t celebrate too soon, however. If we tee off for the fireplace, there won’t be enough gas pressure left for the furnace upstairs. Now, we have 3 options:

  1. We can upsize the gas line. We would only need to increase the diameter of the gas line from the meter to the tees, we would not need to upsize the gas line going up to the attic. This option will likely be one of the more expensive options. If the black iron is old and rusty, and the homeowner mentioned that they smell gas every once in a while, this might be the best option, since it would replace all the gas lines in the crawlspace.
  2. We can run a dedicated line from the gas meter to the fireplace. This option, though redundant, is often the most cost effective. We don’t need to consider the gas pressure drop of the primary gas line if we tee off at the meter, come into the crawlspace, and run an independent 25 ft line to the fireplace.
  3. We can upgrade the gas system. The alternative to a standard low pressure gas system is a high pressure, or 2 stage system. On a 2 stage system, the gas meter will regulate the gas to 2 psi rather than 0.5 psi. 2 psi is far too much pressure for appliances, so an additional regulator needs to be installed prior to each appliance. The gas meter on a high pressure 2 stage system has a red face.
a high pressure gas meter

I write up the cost of each option, and present it to you, explaining the cost, process, pros, and cons of each option. You mention that once your electric water heater in the garage breaks, you would like to upgrade to a tankless water heater. With this information, we now know that the high pressure system is the best option. We know that a tankless, although more efficient, requires a lot of gas pressure while running. By upgrading the system now, installing the tankless in a few years will be simpler and less expensive.

This process will be specific to each house. Some homes already have high pressure gas, which can make things simpler. Other homes might have many gas appliances, or may already be undersized. There are so many considerations to a gas line, it’s impossible to know how simple or complicated a new gas line will be before doing an onsite evaluation.


Before beginning the work, we need to pull a mechanical permit downtown. If there’s no rush, we can request the permit online, and it should be issued in the next few days or so. If we have a deadline, we can go downtown and get the permit same day. We will need to write a description of what work we will be doing, who we will be doing it for, and list our license to be sure we are qualified to do this work.

The Actual Work

Time for the fun part – actually working! I will determine the best materials and methods for the job. Often, this will be a mix of black iron, as well as what many plumbers call tracpipe, which is corrugated stainless steel tubing (CSST). Your plumber should know all the little, but important details involved with this sort of an install, such as having drip legs to prevent sediment from clogging the appliance, having shutoffs to isolate appliances and regulators, and having unions for future serviceability. The code is very specific about where these should be installed.

a gas regulator, regulating gas from 2 psi to 0.5 psi

If we were upgrading the home in our example to a 2 stage system, I would likely install 1 regulator for both the kitchen stove and the fireplace, and a different regulator for the attic furnace. I would utilize the existing gas lines across the crawlspace and up to the attic, as long as they are in good condition, and only run a new gas line for the fireplace.


The morning of the inspection, I will pump up the system to 10 psi. This might seem excessive, since the gas pressure is only 0.5 or 2 psi, but with no leaks at 10 psi, we have absolutely nothing to worry about at the lower pressures. I install a pressure gauge somewhere accessible for the inspector to see, and isolate the gas line we worked on from the rest of the gas system. If we upgraded the whole home to a 2 stage system, we will pump up the entire system, even if we didn’t touch certain gas lines, like the one that runs from the crawlspace to the attic.

a test gauge, to pump up the gas system

Inspectors don’t always tell us when they are going to come, so we aren’t always able to be onsite for the inspection. The inspector will look at the pressure, as well as the materials used, and will check all the little details your plumber was careful to do correctly. You can never be sure that an inspection will pass, but whether or not it passes, you should call the plumber afterwards and say the inspector came. He will come back to hook everything back up.

Enjoy your new appliance!

After all is said and done, you can enjoy sitting by your new gas fireplace.

my dog Canela sitting next to our fireplace

If you live in the Fayetteville, NC area, and you’d like an estimate for a gas line, feel free to give me a call at (910)292-9870

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