How To Run Your Own Gas Line Underground

Running a gas line underground to a garage, pole barn, or any separate outbuilding from your home is an excellent project for even the average do-it-yourselfer. Digging that ditch is the worst part, but a few simple steps can help the project be completed safely.

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  • Purchase a mechanical permit to run a gas line.
  • Purchase PE pipe with risers and fittings.
  • Dig your trench at least 18 inches deep.
  • Cut and lay in your pipe with vertical risers and plumb.
  • Pressure test pipe with air.
  • Call for inspection and get approved.
  • Connect the ends of the pipe to the source and other gas lines.
  • Check for leaks at your new connections.

The materials needed are simple and easy to assemble, with no special tools required. You can get a visual of the different sizes of these materials by going here to Amazon. You no longer need the PE pipe welding machine.

You might want to rent a trenching machine.

Remember to call 811 “Call Before You Dig” or look at their website. In 2005, the FCC made 811 a universal number for 71 universal services. Canada has done the same thing with 811, as you can see on their website about digging in Canada.

I’ve helped many of my customers with this project even though they probably could have done the whole job independently. This is especially true now with great new products like (ad) PE pipe and fittings available online at Home Depot.

These products made by (ad) Home-Flex can also be shipped to your door from Amazon.

Sometimes, they don’t want to hassle buying the pipe and feel safer knowing someone has done this before. So, I would supply the materials and provide a helping hand, and I wouldn’t have to dig that ditch or fill it in.

The materials for running a gas line underground are readily available now, and you, as a homeowner, can do gas piping for your home. This is true in almost all counties in the USA, but I’m not sure about countries other than the USA. Just call your local building department if you have one and verify.

If you are uncertain about doing this DIY project, I wrote what I thought was a convincing article about how to find a good contractor: 30 Questions When Buying A New HVAC System. Read it and pick the questions that apply.

This article aims to help you feel confident that you can do this job. Let me fill in the blanks and help you run that pipe so you can enjoy a warm winter working on that hot rod or whatever projects your shop allows you to turn out.

You Need A Mechanical Permit To Run Your Gas Line

If you are unfamiliar with getting mechanical permits, it’s generally easier than applying for a building permit. A few counties make it very hard, but you can do it.

In the two states I’m used to doing business in, it simply filling out a form and checking a few boxes. It’s done online now, and we just dropped by the courthouse and picked up the permit. Inspections are scheduled on a phone app, or you can call.

And then, of course, paying for the permit. It should be safe to say that the average cost for a mechanical permit across the nation should be around a hundred dollars or more, with inflation.

When you purchase your permit, you will be given all the instructions on finalizing the inspection for your particular area.

Keep all your paperwork, especially if you ever sell your home, so you have immediate proof that you purchased proper permits and had a final inspection.

In most areas, you will be given a bright card to be displayed so that the inspector driving by can spot your home in case he can’t see or read the address.

You will also be given the signature card the inspector will sign when they approve your job. Keep this in a safe place. Your county probably will have this on record, but you can be the judge if you want to trust their record-keeping system.

I just had a lady call me. She bought a home where I installed a heat pump several years back. The county contacted her to finalize permits on the heat pump that were still open. I could never get my customer to call for inspections. She had no proof of final inspection and will have to buy a new permit.

I’ve been researching this and related things on gas piping because things vary from state to state, and I don’t want to give out wrong information. For example, if you search “Do I need a permit to run a gas line underground?”.

One of the answers I got while searching on the most popular search engine was…………..

If you try to install a new gas line yourself, you may use the wrong type of pipe, and then the gas can build up, resulting in an explosion. Your life isn’t worth the money you may be saving by undertaking this dangerous task on your own.

perryplumbing.com

So, don’t use the wrong pipe. Follow along and do this yourself, safely and reliably. Discover the best way to run a gas line underground.

How Deep Does A Gas Line Have To Be Buried?

Generally, the depth of your ditch should be 18 to 24 inches. The type of terrain will have something to do with the depth.

Always check with your local building department for specific codes regarding the depth of your ditch in your area.

You will be using a form of plastic pipe, so the bottom of your ditch should be clear of rocks and debris that can cause problems with the new pipe. If the ditch is rough, it may need to be dug deeper and filled with a few inches of good, clean-fill dirt or sand to protect the gas line.

Code requires some additional work before you cover your pipe in the ditch. An inspector will want to inspect the ditch before you cover the pipe, and underground piping has to be detectable after it’s covered.

More than one method can be used for locating underground pipes. If you’re curious about these methods, you can check out this site; it’s well-illustrated.

When future tenants begin new projects that require disturbing the earth around your house, it’s vital that your gas line can be discovered quickly and accurately.

This Is How To Locate Gas Lines Underground

Usually, a green-coated wire is buried alongside your gas line.

When you call before you dig, people come to find buried TV cables, phone lines, water lines, and anything else that may be buried on your property. They will attach a signal generator to the green tracer wire, which enables a handheld device to read the location of your gas line.

What Kind Of Pipe Is Used For Natural Gas Underground?

Some of my customers have asked me what type of pipe is used for underground gas lines. I like to steer them away from using steel pipe because of underground leaks. Coated steel is an option, but it is more difficult than using PE pipe.

Polyethylene pipe, which we will refer to as PE pipe, is made from the polymerization of ethylene. It’s yellow, comes in a roll, and it’s very lightweight. You can probably fit all you need into your trunk.

Polyethylene (PE) gas piping is the most widely used plastic piping material for the distribution of natural gas. PE has a well-documented inertness to both the external soil environment and to natural gas. Extensive testing and over 45 years of successful field experience confirm that the long-term strength of polyethylene is unaffected by natural gas and its common constituents.

plasticpipe.org

Can you run a steel gas line underground? Yes, you could use fusion bonded steel pipe, but it’s so much more work, and if your ditch is over 21 feet long, you will have joints underground and have to cut and thread the pipe, and the time involved is so much longer, and it’s just not worth talking about here.

With PE pipe, you will have one single piece of pipe from end to end, and it’s so simple and clean compared to the cutting and threading of steel pipe. Don’t do it. PE pipe is superior to anything else for gas pipe in a ditch.

I can only speak for half of a dozen counties I’ve done work in, but as an example, let me use my own shop. I installed the gas line after construction. I core-drilled a two-inch hole through the bottom plate and the concrete, with the ditch ending just under the footing. I then poked the riser up into the wall of the garage.

This line from the meter runs underground across the backyard to the gas meter next to the house.

It was inspected and passed with flying colors.

Before PE pipe and easy-coupled fittings were available, we had to have a local propane company fuse the risers on the end of our pipe.

We would have to give them the exact dimensions end to end and hope you got it right when you laid it in the ditch. Now, you can lay it in the ditch and cut it to fit on the spot.

The internet has some comments about using PVC pipes. PVC stands for polyvinyl chloride. That’s something to shy away from. The information is unclear because of the misinformation available. PVC has specific uses, and natural gas and propane are not listed.

This is where that plumber says you could use the wrong pipe and cause an explosion. Things are constantly changing. That includes piping and products used for natural gas and propane. Do your homework and buy the right stuff.

What Size PE Pipe Do I Need?

The diameter of the pipe you need is determined by the length of the pipe and the Btu load (size of your equipment) at the end of the gas line.

Be sure to consider any future appliances you may want to add in the future. Upsizing the PE pipe in your ditch is cheaper now than later.

You may have already got a quote or two to do this project. That’s probably why you’re looking into doing it yourself. They may have told you the size or put the correct size on their quote.

Another option to know the correct one would be to call tech support for the brand of pipe you bought. They may or may not want to be helpful. Try another brand for tech support.

One last option is to pay an HVAC contractor or a plumber to come out and do the sizing. They could even do that over the phone if you gave them the correct information.

If you want to figure it out yourself, check out these charts and the forum below.

How Much Should It Cost To Bury My PE Pipe?

These prices vary in different areas of the country, so I tried to list them on the high side of what I think should be.

Permit cost should be around $100.00

A daily rental for a 24″ trenching machine is less than $200.00, and closer to $125.00 for a four-hour rental.

On Amazon, you can get 100 feet of 1″ PE pipe for just over $200.00, and I chose 1″ because it’s an average size.

Add in two risers at about $85.00 each for two would be $170.00

There are always miscellaneous items like a pressure gauge for less than $10.00 and the fittings to connect. You may find a reverse-threaded coupling handy.

Some inspectors may not want to see a union in this application. A reverse-threaded coupling would make the job look more professional and impress your inspector.

Reverse couplings can be intimidating initially, but with a little trial and error, you’ll get the idea.

It’s nothing more than a short length of pipe or nipple with right-handed threads on one end and left-handed threads on the other. A special coupling fits on the left-handed thread end, connecting two pipes like a union.

The arrows point to the unpainted reverse coupling nipple on top connected to the riser at the bottom arrow.

So, back to how much it costs to run a gas line underground: remember, prices are crazy these days, so do your homework and check around for the best prices and delivery if necessary.

That should be a good budget number to get some ideas with. I know you’re a prudent shopper who can do it for less. If you’re like me, you take these numbers and double them. It just never seems to fail. But look on the bright side with all the labor costs you will save.

Conclusion

The articles on my website have been fun and are beginning to return a little revenue from ads and some affiliate links.

I aim to replace my part-time or semi-retired income from working in the HVAC arena and fully retire within the next couple of years.

So, how do they run the gas line underground? Simple, right? Now that you know, you can run a gas line underground for a grill, maybe a fire pit, or any other remote gas fixture you can think of.

Running propane gas lines underground is the same principle. Be sure to follow local codes and restrictions as they vary in jurisdictions. Learn the differences between natural gas and LP or propane. One is lighter than air, the other heavier.

Consider an earthquake safety shut-off valve. I wrote an article about these safety valves. You can read it here.

Customers ask about running a copper gas line underground. In some counties, it’s legal to run copper gas lines aboveground but never underground, which I’ve never experienced or heard of. Electrolysis will attack copper and eat holes right through it.

Chad Peterson

Chad Peterson is a veteran of the HVAC industry since 1977. "I like to explain heating and air conditioning problems in a way the average home owner can understand. "

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