Running utiities to outdoor barbeque

[avorancher]

When we had our house built, I had the contractor run hot & cold water (copper pipe), a separate 15amp electrical circuit, and LP gas line (black pipe) to one spot on the outside of the house. Now, I need to extend all of these about 40 feet to a masonry barbeque/outdoor kitchen unit I want to build as a DIY project.

Digging trenches in this part of the yard is difficult because of rock and numerous irrigation and drainage pipes that all seem to converge in this area. Too tight for my backhoe, so trenching will be done by hand, therefore I want to keep trenching to a minimum so I can finish this year.

I have several questions that I hope you'all can help with:

1. Can I run all these utilities in one trench?

2. Should I convert the water to schedule 40 pipe, or just put copper inside a pvc sleeve to protect it? I've also considered just running the cold and getting an "instant" water heater to mount under the sink.

3. Can I run these utilities through a thick concrete slab used for an outdoor fireplace? The raised firebox will be about 24" above the sleeves that carry the utilities, so heat shouldn't be a concern.

 

[Varmintmist]

If you can put them all in the same trench depends on your building codes.

For service drops elec and phone feeding the house you cannot put them in the same trench with gas. I've seen it done, but its not code.

Probably isnt a great idea. Think about it, gas leak looks for a place to go, goes to the elec conduit that ends in a fuse box, a breaker makes a spark when it is flipped........

You will probably be ok. I dont know if I would do it but I dont like gas anyway and dont know a lot about it.

PVC for the water, you can run 1/2 and put them on top of one another. Since PVC is cheap, I'd run hot out to since you have it available. Insulate it before you cover it.

You can bring conduit up through the pad, or when you are forming, form out a 6x6 hole. Eaiser to change that way if you clip one off with an errant lawn mower. Put the hole under the sink and feed everything from there.

 

[avorancher]

Thanks for your reply.

Unlike Natural Gas, LP is heavier than air and sinks. I figure even if I dig a parallel trench, the gas would find it's way through the rock anyway. I don't like the idea of having gas and electric together, but the options don't sound good either. I won't have any electrical splices or connections underground to spark, but I get your point.

When I think about it, the gas and electric is already a couple inches apart on the side of the house, and they will be together again inside the barbeque unit which has a much larger volume of space to gather fumes. I do plan on venting it well and using cutoff valves at each end.

Using PVC for water makes sense...

 

[Varmintmist]

When we are talking PVC we are talking about regular black water pipe?? That would be a better solution. No joints to worry about except at the ends, and I dont think sced 40 is potable rated. Not sure if you can get it in 1/2 but use adapters and go 1 in.

If you are in a freeze thaw area you might want to think about a frost free valve. The kind used in barns.

If you are good with the gas its great by me, I dont do gas unless the wife made beans /forums/images/graemlins/grin.gif I just know that you cant use the same trench as service drops elec and phone.

 

[Varmintmist]

Went by TSC, 3/4 in water line 20.00/100 foot

 

[v8dave]

For the electrical lay in a 1" Gray PVC conduit, use preformed bends (they are nice and long). Make no more than 2 90 degree bends (more bends are possible but difficult to pull through). Then run the three wires (black, white, green/bare) in the conduit. Use three separate insulated wires, not romex, the separate wires pulled through together will be easier than pulling romex. This way if anything goes wrong you can re-pull the wires.

If you do a separate water heater like you suggest, an electric heater will use about 10 amps (for a small one). Doesn't leave much spare electric capacity.

I'd be careful about putting the gas in with the rest.

Don't run the pipes inside the concrete, run them under the concrete and then up through a hole left in the concrete as suggested in a previous post.

I just learned this from a plumber finishing my shop. Water pipes vibrate when water runs through them. After a [long] while a sharp rock burried alongside will wear through even copper pipe. So, either wrap the copper pipe with a plastic wrap (made specially for this) or run it in the PVC like you suggested. Or, bury the water pipe with sand as a first layer before throwing on the dirt or concrete.

Don't forget to run a waste water line from the sink through the concrete to where ever you are going to dump the gray water.

 

[EddieWalker]

CA code is about as scary as it comes. Earthquakes have made for more changes than I can comment on, or wish to deal with. Been there, done that.

For only 40 feet, I'd run copper water all the way if you can sodder. If you change to PVC, your in code violation and somebody down the road will have to change it and you still have to sodder on the threaded adapter from copper to plastic. I will admit to running plasti as much as I can, but will do copper when I have to.

I'd also run both hot and cold. For the price of the copper, you can pass on the on demand water heater. Besides, it will need replacing one day anyway.

When you come up from the ground through the slab, use pipe insulation. It's cheap and protects the pipes from wear. Both the pipe, and the slab will move on you.

In the area of CA I worked, code on electrical was Sch 80 grey pipe or metal abover ground to a depth of 18 inches. After that you didn't need conduit if you have direct bury wire. Gophers will find the wire one day, so I always use conduit, but I just use thin wall to protect the wire.

I've never run thin wire seperately, just 00 and up. For what you're doing, 12/2 romex is plenty and it's cheap. Just slide it in one joint at a time and glue it last.

Gas in the same trench with anything is usually a big no no. I don't remember the distance requirement, but when gas leaks underground, it stays in pockets and just gets worse. I'd call your propane supplier and find out what they recomend. Gas is scary and not something to cut any corners on. There is also the issue of having to dig later if you have a problem. Ten years from now, it's real hard to remember exacty where everything is in the same hole and even easier to damage one of the lines looking for anohter.

Why can't you get your backhoe in there? I have a full size 555E, and I will brush up against a foundation when digging a trench. 40 feet is a long way to dig by hand, especially two trenches.

Don't forget to post pictures and when you finish, tell us what you did and why.

Thanks,
Eddie

 

[mikim]

Just thinking .... (40' of any PVC is cheap so ...) ..what if .. you ran a 4" sched 40 PVC ...and inside that you ran 2 -- 3/4" PVC pipes and inside them ran your copper water lines ....THEN also in the 4" run a grey elect PVC .... then OUTSIDE that 4" run your gas line similarly wrapped in a seperate PVC and vent that pvc so if the gas line ever did leak it would vent out.... jus' trying to figure a way to save digging ....

 

[avorancher]

Some really good ideas... thanks everyone.

Mikim, I like the idea of running multiple "sleeves" for each utility. That protects the pipes against the rocks and concrete, plus gives me access if I ever need it by getting to the ends. I'm thinking that 3 separate sleeves would be ever stronger than using one 4 inch for elec. and water. LP gas sinks, so I'm not sure if I can vent it.

Eddie, getting the backhoe in there is possible, but there is so much rock and irrigation/drain pipes that I'll end up digging most be hand anyway (pick axe and rented jackhammer). The backhoe will dig through soft rock, but most of mine rings like a bell and stings the hand when you hit it with a pick. That is why I dread digging in that area. Two parallel trenches will just become one as I lift out the rocks anyway, so I'll just make the trench wider to start with to get more separation.

This particular area used to be 13 feet underground before they graded for the house, so I'm down to the non-decomposed granite.

 

[mikim]

I understand that gas sinks .. my thought about the vent I guess was more of putting a "T" in the sleeve line with a vertical up ... if the gas line leaks .. I would hope it stays in the sleeve, fills it to overflowing, and you smell it when walking by thus discovering the leak before you would otherwise....On the sleeves ... in my head there are 3 sleeves inside the 4" sleeve ... doubled up sleeving...if ever a redig is needed they'll hit the outer sleeve but all the lines will be protected inside their inner sleeves. overkill? sure. but for 40' why not? If it were 400 feet ... I'd think again.