View Full Version : laying conduit in a trench


sands35
06-26-2013, 06:12 PM
I'm a few days away from laying down conduit in a trench. Any hints and tips? Specifically wondering if I should layout the pipe and glue it next to trench and then lay it down or glue it up and drop it in as I go?

One of those jabs that is pretty messy with glue and dirt and want to hear some best practices 1st.

Thanks!

jhelrey
06-26-2013, 07:24 PM
I snaked the wire through all of the individual pieces. I glue them together and then roll it into the trench.

Roots
06-26-2013, 07:27 PM
There's no special secrets to it that I can share. For small runs it's not much of an issue to use solvent on the pieces and than drop it in. For large runs, being in the trench installing a stick at a time is the standard practice. Keep some rags handy or a small tarp to work over, to help make sure you don't have any debris enter the conduit as you go along.

I snaked the wire through all of the individual pieces. I glue them together and then roll it into the trench.

That's a major no-no.

porschedude996TT
06-26-2013, 07:28 PM
Glue them as you go or up out of the trench out of the trench is cleaner. If you don't put a pull rope in the conduit, you can use a wad of paper towels tied to a pull rope and use a vacuum cleaner to pull it through.

kiatech
06-26-2013, 07:39 PM
How big of pipe are we talking? I've been running 1"-6" pvc in the ground every day for the last few months. I may be able to help. How deep and wide is the trench?

Roots
06-26-2013, 07:51 PM
How big of pipe are we talking? I've been running 1"-6" pvc in the ground every day for the last few months. I may be able to help. How deep and wide is the trench?

Sigh, I remember the days of being an apprentice :D Hope you're enjoying the opportunity! Er, I think you just started an electrical apprenticeship?

Aceman
06-26-2013, 07:55 PM
Unless it's big pipe, say over 2.5" or a big nice wide ditch, it's almost always easier to glue your pipe together up above and then drop it in the ditch.

sands35
06-26-2013, 07:59 PM
Code is 24" deep. I have a 6" wide (mostly) and ~30" deep trench. My back yard is an obstacle course of multi-tiered gardens, trees and a small pond. So what should be a 95' run is really about 120'.

The local AHJ is going to allow me to run conduit and nat gas in the same trench - which saves me a lot of work. The trench is 90% done. Just need to do the hand work up against the house and the garage, clean up the bottom of the trench and cut one pretty big root with a chainsaw.

My plan is to:
Layout along side the trech.
Glue section by section
drop it into the trench but keep the as yet unattached end above ground.

It rained, of course, twice, since the trench was opened, so some of it is still sloppy.

Rookie2
06-26-2013, 08:03 PM
did 1500' 4" x20' above trench with helper , keep the ends covered , gluing takes a rhythm with 20' sticks

sands35
06-26-2013, 08:06 PM
Thanks!

I'm asking because there is typically simple things that make the job 100% simpler and easier. Normally I'll figure that out on the last 5% of the job. Of course, I'll probably never lay conduit again in the ground, but you never know.

Gooch
06-26-2013, 08:44 PM
Lay a piece of pipe perpendicular to your trench to hold you end up for gluing additional pieces on.

CNGsaves
06-26-2013, 11:23 PM
Code is 24" deep. I have a 6" wide (mostly) and ~30" deep trench. My back yard is an obstacle course of multi-tiered gardens, trees and a small pond. So what should be a 95' run is really about 120'.

The local AHJ is going to allow me to run conduit and nat gas in the same trench - which saves me a lot of work. The trench is 90% done. Just need to do the hand work up against the house and the garage, clean up the bottom of the trench and cut one pretty big root with a chainsaw.

My plan is to:
Layout along side the trech.
Glue section by section
drop it into the trench but keep the as yet unattached end above ground.

It rained, of course, twice, since the trench was opened, so some of it is still sloppy.

Which conduit is going on bottom?? It would be easier to run the continuous yellow polyethlene plastic pipe for natural gas, then backfill 6" sand or sandy loam, then the 10 ft sticks of electrical conduit after you glued them together first above ground.

Have you considered running an extra smaller electrical conduit like 1" Sch40 to be for internet/CATV/phone/intercom?? If you could get away with it, this could serve as your "tracer wire" buried at 12" and no big deal if it got tore up by inappropriate digging since non-critical and not dangerous. Most code does require tracer wire (ie yellow for NG, red for power, orange for telco, etc) so you may actually have to bury actual tracer wire(s) at 12" level anyway.

P.S. With the strange route that your trench runs, be sure to draw up grid (drawn to scale) so that you know exactly where that trench is 5 years from now when all grown over with grass and vegetation.

sands35
06-27-2013, 05:59 AM
Lay a piece of pipe perpendicular to your trench to hold you end up for gluing additional pieces on.
That is basically what i thought i'd do. Thanks!

sands35
06-27-2013, 06:05 AM
Which conduit is going on bottom?? It would be easier to run the continuous yellow polyethlene plastic pipe for natural gas, then backfill 6" sand or sandy loam, then the 10 ft sticks of electrical conduit after you glued them together first above ground.

Have you considered running an extra smaller electrical conduit like 1" Sch40 to be for internet/CATV/phone/intercom?? If you could get away with it, this could serve as your "tracer wire" buried at 12" and no big deal if it got tore up by inappropriate digging since non-critical and not dangerous. Most code does require tracer wire (ie yellow for NG, red for power, orange for telco, etc) so you may actually have to bury actual tracer wire(s) at 12" level anyway.

P.S. With the strange route that your trench runs, be sure to draw up grid (drawn to scale) so that you know exactly where that trench is 5 years from now when all grown over with grass and vegetation.
Good idea, thanks. When the inspector is out to look at the gas line, i'll ask about the depth for the conduit. I was planning on running 2, one for power and one for telco. The power is intermittent. Basically a signal lamp with switch in the house and lights in the garage. Can't hear a phone with hearing protection on and power tools running. Simple way for my wife to get my attention. So i'm not worried about interferance with the ethernet.

Main power for the garage comes from the pole, not the house.

Rookie2
06-27-2013, 08:25 AM
ever hear of wireless ? they make car starters that reach 500'. for just a signal wire i wouldn't do any trenching

sands35
06-27-2013, 11:48 AM
I thought about that but.... I need a trench anyway for nat gas. Running a 2nd conduit is trivial. I'm going to put my disk backup in the garage so I want a gigabit line for that.

Highbeam
06-27-2013, 12:51 PM
Lay a piece of pipe perpendicular to your trench to hold you end up for gluing additional pieces on.

This is my standard procedure. You don't want to be down in the trench, or getting in and out of the trench, while gluing and placing conduit. I usually use two short shunks of 2x4, and leapfrog them as I progress down the trenchline.

arrowhead
06-27-2013, 01:33 PM
Lay a piece of pipe perpendicular to your trench to hold you end up for gluing additional pieces on.

I had about 120' to lay last weekend so I got the first section started and then laid scrap pieces of wood all the way every 8-10' or so and at any fittings. Helps to do it this way if your by yourself. I also keeps the pipe at the same plane so your not trying to fight it sticking up at an angle coming out of the trench. I did dry fit all the pipe in the trench first so I had everything cut and joints fitted first, pulled it all apart, slid the wire into the individual pieces and then assembled over the trench on the boards. Pulled the boards one at a time and the piped laid in the trench prefectly.

kiatech
06-27-2013, 05:37 PM
I'm in trenches that are 9' deep and 4' wide then benched 3' on each side. For a ditch that small I would glue it together and then kick it in the ditch, make sure you tape up the ends before putting it in the ditch. Its allot more flexible than you think.

kiatech
06-27-2013, 05:40 PM
Sigh, I remember the days of being an apprentice :D Hope you're enjoying the opportunity! Er, I think you just started an electrical apprenticeship?

Yes sir, that's me.

kiatech
06-27-2013, 05:42 PM
I would buy a fish tape out or blow/suck jet line through it.