Trenching for gas line

[theoldwizard1]

Okay, it's not for a garage, but it could be !

My son's house is a tri-level. Lower level is half below ground. It is typically cool in winter. There is a wod burning fireplace that was cleaned and inspected a few years ago and ready to go, but there is no source of low cost wood in his subdivision ! We we were discussing a gas fireplace insert.

The problem is the gas line. We would have to trench from one side of the house, around the front, to the other side of the house (main level is on a slab, lower level is finished). I know we would have to rent a demolition drill to get through the walls below grade.

• How deep does gas line need to be buried ?
• What kind of line is used these days (gas company uses some kind of yellow plastic looking stuff) ?
• Do the small walk behind/ahead trenchers like they rent at HD do a decent job ? Do they make a big mess of the lawn (1 year old sod) ?

 

[EOC_Jason]

Depending on where you live, your municipality or county engineer's office should be able to tell you their requirement. I don't think it has to be very deep after the meter.

Yep, yellow gas pipe I think is like HDPE. Any plumbing supply store will have it when you tell them you need a big roll of pipe for your gas line. Don't forget about the fittings you will need to go from that to regular pipe and / or your gas meter.

In my experience trenchers actually do a good job once you have it dialed in and going. Makes a nice clean trench and the auger piles the dirt in a little pile right next to it making backfillng very easy. If you've never used one before, the guy at the rental place will explain how to operate it, they are not that complicated.

 

[Tunajoe]

In our area (so cal) I had to get certified to install heat fusion PE.
You'll have to rent to the equipment to melt it together.
I took the class and it was easy. Your area may be different.
I think in our county the gas line has to be 18" deep.

 

[CNGsaves]

Prior owner did that very thing to my fireplace . . . put in Natural Gas insert and ran the buried yellow plastic polyethelene pipe that connected just after the meter.

Typical depth is 18 inch minimum, but some states may be 30 inches deep or more. Need to give a call to regulated natural gas company as they'll give you the details.

The buried yellow plastic polyethelene pipe will have Risers that transition the plastic to steel above ground (they are officially anodeless risers). See example below:
http://rwlyall.com/elog2/pagemasters/datafolder/documents/brochures/LIT-STDLYDS.pdf
At each end of buried NG run (ie at top of riser), you should had shutoff valves. Finally, the NG line MUST enter the house above ground with generally black pipe steel to your final location (ie fireplace). You will NOT want any kind of below ground entrance for NG line as that could allow leaks to migrate into the house . . . . . thus the requirement for above-ground entrance into house. This code requirement works for both NG and LPG even though leak would behave differently . . . NG is lighter than air and would dissipate upwards, whereas LPG is heaver than air so it would pool in low spot (ie with LPG you'd absolutely want any leaks to have wind blow it away).

In KS or OK, you can use either FUSED or Stabloc connector for the PE yellow plastic buried pipe to the riser. Also, you'll need a Tracer Wire in the trench so that buried plastic pipe can be located later.

Do it right with no shortcuts . . . just like the regulated natural gas company would do it.

 

[skulldrinker]

If I remember correctly mine had to be at least 18 inches deep for the plastic line. If it is less it has to be covered with a couple of inches of concrete. But like what everyone says you must find out what is code by you.

 

[HoosierBuddy]

No one told you the most important thing.

Call 811 before you dig. Stay 2 feet off the marks (or more) with the trencher.

Phil

 

[ISFast]

Also, don't forget to do this on a clear day when the ground is dry. If it rains and the ditch is open it will cave in and/or fill in due to rain. The pipe, if it is kind of in the ground at this time, will float to the top or at least not at the bottom of the ditch which makes for an inconsistency in pipe depth and a pretty hard way to figure out how deep it is. Tracer wire will stay on the bottom due to its heavier compared to water and the pipe will float due to it still has air in it and acts like a boat. So when you are trying to find your pipe down the road it won't be next to the tracer wire giving the person locating it incorrect info.

Now if you get caught in a sudden rain storm or something that could flood the ditch like a waterline break then either get the pipe and tracer wire in the ditch and cover it up as much as you can with dirt or don't put any of it in the ground. You will have to dig out the ends to the bottom of the ditch to keep that depth after the fact.

This is a few pointers from a fella who put many miles of poly pipe in the ground.

 

[plumbstupid]

Call your local gas company and they can tell you how deep the line needs to be. Here we are only required to them 12 inchs deep.