How to Install a Gas Line

Installing a gas line is probably not a task to take on as your first do-it-yourself project. The risks of making a mistake outweigh the costs of a professional. However, experienced do-it-yourselfers can install a gas line as safely as a professional. Despite the narrow margin for error, the individual steps are no more demanding than plumbing or electrical work.

Be sure to check local regulations - for example in the UK, it is illegal to modify a gas installation without a professional certificate of competence (currently the Gas Safe scheme) and doing so could result in prosecution, a fine or even imprisonment.


  1. Image titled Install a Gas Line Step 1
    Buy the right gas pipes and fittings for the job. Most domestic gas lines use 1/2-inch (1.27 cm) through 1 1/2 inch (3.81 cm) black pipe, while large commercial projects sometimes use larger fittings up to 8 inch. You should buy a total pipe length of 6 to 12 inches (15.24 to 30.48 cm) longer than you need to account for pipe overlap and waste.
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    Turn off the gas to your house. The valve will be at your gas meter on the side of your house and should shut off entirely with a quarter-turn. A position perpendicular to the pipe indicates a closed valve, but you should double-check by confirming that the meter is no longer moving.
  3. Image titled Install a Gas Line Step 3
    Extend your existing gas line by fitting the valves and pipe lengths you need to add a gas line that will reach your new appliance.
    • Coat the threads of the pipe ends using pipe glue or tape. This is essential to establishing an airtight fit. If using tape, be sure that you wrap in a clockwise direction.
    • You can make your job easier by assembling some lengths of your gas line in your garage or shop, then moving them to the crawl space or wall where your gas lines run. Be wary of 90-degree bends if you do this, since those make turning the pipe to tighten it in exponentially more difficult.
  4. Image titled Install a Gas Line Step 4
    Use a flexible pipe to connect the end of your new gas line to the appliance. Thread it onto the end of the gas line using pipe glue or tape, just as with all the other connections. However, you will rarely need the pipe glue or tape for the final attachment to the appliance itself.
  5. Image titled Install a Gas Line Step 5
    Spread a mixture of 1:1 water and dish liquid over each seam in your gas line. If bubbles appear, you have a leak. Unscrew that section, strip off the pipe glue, and reattach with new sealant.
  6. Image titled Install a Gas Line Step 6
    Turn the gas back on by returning the valve to parallel to the incoming pipe. Test your appliance to ensure the gas is flowing properly.


  • Never loosen a gas pipe once you've started to tighten it. This will ruin the seal from your pipe glue, and you will have to start over.
  • In Oregon you have to have a shut off valve to the appliance. Also you have to have a tee with a 2" nipple with a pipe cap to act as a dirt trap. One end of the tee hooks to the gas line coming through the floor than your tee faces down with your nipple. Than your valve, next your flex hose to the appliance.
  • You can also test your gas line by disconnecting the main line from the meter. Install a pressure gauge with a way to fill the line with air. Then fill the line with about 25 pounds of air. Check your line for leaks with soap and water. If no leaks recheck line pressure and let it set overnight. If there is no pressure loss there is no leaks in the line. It would be best to have an inspector check your line pressure and come back and sign off on it.


  • This is not a job for beginners. If you've never worked with gas lines before, get an experienced friend to coach you through your first attempt.
  • Ensure proper line sizing was used to handle the BTU load you will be drawing with the new appliance.
  • A pressure test should be done prior to firing up any appliance to avoid explosions.

Things You'll Need

  • Gas pipe and fittings
  • Pipe wrenches
  • Pipe glue or tape
  • Dish soap

Article Info

Categories: Plumbing Drains Waste and Vents