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Posted: 9/12/2011 5:45:20 AM EDT
I want to finally install a lamp post near our front sidewalk. There is an electrical box for this purpose already on the side of the house so my plan is to get proper burial cable, some of the plastic conduit, and trench the 15' run to where the lamp post will go.

The only problem I have is that I need to get the wire under my poured concrete sidewalk. Builder was supposed to have placed a pipe or two, but I can't find them. If my memory serves me right, concrete was poured over the clay "soil" we have here in S. Ohio and no gravel was used. Short of hiring some North Koreans to tunnel it for me, whats the best approach? I will measure, but my estimate is that the sidewalk is about 3 feet where I need to run the wire. On one side is a planting bed with some shrubs I need to move first, the other side (where the post will go) is just a bare planting bed/packed soil.
Link Posted: 9/12/2011 5:51:11 AM EDT
Water pick

Take a garden hose with a jet stream adapter and a piece of PVC and burrow your way under the sidewalk, very simple and effective, unless you are afraid of getting muddy but it will work.
Link Posted: 9/12/2011 7:03:33 AM EDT
[Last Edit: 9/12/2011 7:09:33 AM EDT by jacassc]
Drive a piece of 3/4" emt conduit. Smash one end, then cut it on an angle to make a point. Lay conduit in trench leading up to sidewalk and pound it home. When it pops out on the otherside cut off the end and push UF wire thru...you may want to install 2 insulating bushing on the conduit ends afterwards to protect the wire from the conduit edges. I've done it many times before

Not exactly the same but I recently finished doing this

Pic 1

Pic 2

Pic 3

Pic 4

Link Posted: 9/12/2011 7:11:25 AM EDT
water hose and pvc pipe
Link Posted: 9/12/2011 9:15:10 AM EDT

Originally Posted By jacassc:
Drive a piece of 3/4" emt conduit. Smash one end, then cut it on an angle to make a point. Lay conduit in trench leading up to sidewalk and pound it home. When it pops out on the otherside cut off the end and push UF wire thru...you may want to install 2 insulating bushing on the conduit ends afterwards to protect the wire from the conduit edges. I've done it many times before

Not exactly the same but I recently finished doing this

Pic 1

Pic 2

Pic 3

Pic 4


I'm not sure that UF can be put through conduit by code, and you certainly can't have an underground change in conduit type.
Link Posted: 9/12/2011 10:16:39 AM EDT
[Last Edit: 9/12/2011 10:17:18 AM EDT by jacassc]
Originally Posted By VARifleman:

Originally Posted By jacassc:
Drive a piece of 3/4" emt conduit. Smash one end, then cut it on an angle to make a point. Lay conduit in trench leading up to sidewalk and pound it home. When it pops out on the otherside cut off the end and push UF wire thru...you may want to install 2 insulating bushing on the conduit ends afterwards to protect the wire from the conduit edges. I've done it many times before

Not exactly the same but I recently finished doing this

Pic 1

Pic 2

Pic 3

Pic 4


I'm not sure that UF can be put through conduit by code, and you certainly can't have an underground change in conduit type.


The emt is used just as a sleeve to bore under the concrete sidewalk....a 3 foot piece
Link Posted: 9/12/2011 10:19:14 AM EDT
Originally Posted By NukeThemTillTheyGlow:
I want to finally install a lamp post near our front sidewalk. There is an electrical box for this purpose already on the side of the house so my plan is to get proper burial cable, some of the plastic conduit, and trench the 15' run to where the lamp post will go.

The only problem I have is that I need to get the wire under my poured concrete sidewalk. Builder was supposed to have placed a pipe or two, but I can't find them. If my memory serves me right, concrete was poured over the clay "soil" we have here in S. Ohio and no gravel was used. Short of hiring some North Koreans to tunnel it for me, whats the best approach? I will measure, but my estimate is that the sidewalk is about 3 feet where I need to run the wire. On one side is a planting bed with some shrubs I need to move first, the other side (where the post will go) is just a bare planting bed/packed soil.


North Koreans??? WTF!!!

I always import some Irish to do my dirty work...

Link Posted: 9/12/2011 10:48:34 AM EDT
Another vote for the water jet tunneling method. Just need to dig small pits on both sides, then using a piece of PVC pipe with hose barb on the end, jet it. Should take less than 10 minutes. Messy for sure but FAST.

I jetted a 5 foot vertical hole to set a flag pole, took 30 minutes. But I had to "trip out" and take the jet nozzle off for more flow to "clean" the hole. No way I would have done it with a post hole digger in 30 minutes.

Another benefit is safety. You won't damage utilities.
Link Posted: 9/12/2011 11:17:36 AM EDT
Originally Posted By VARifleman:

Originally Posted By jacassc:
Drive a piece of 3/4" emt conduit. Smash one end, then cut it on an angle to make a point. Lay conduit in trench leading up to sidewalk and pound it home. When it pops out on the otherside cut off the end and push UF wire thru...you may want to install 2 insulating bushing on the conduit ends afterwards to protect the wire from the conduit edges. I've done it many times before

Not exactly the same but I recently finished doing this

Pic 1

Pic 2

Pic 3

Pic 4


I'm not sure that UF can be put through conduit by code, and you certainly can't have an underground change in conduit type.


Short pieces of conduit can be used for physical protection without complying with the rules for a 'conduit system.'

Other than protecting the cable from the sharp ends of the conduit nothing else is required.

Link Posted: 9/12/2011 11:44:58 AM EDT
[Last Edit: 9/12/2011 11:45:14 AM EDT by Delta]
Originally Posted By brickeyee:
Originally Posted By VARifleman:

Originally Posted By jacassc:
Drive a piece of 3/4" emt conduit. Smash one end, then cut it on an angle to make a point. Lay conduit in trench leading up to sidewalk and pound it home. When it pops out on the otherside cut off the end and push UF wire thru...you may want to install 2 insulating bushing on the conduit ends afterwards to protect the wire from the conduit edges. I've done it many times before

Not exactly the same but I recently finished doing this

Pic 1

Pic 2

Pic 3

Pic 4


I'm not sure that UF can be put through conduit by code, and you certainly can't have an underground change in conduit type.


Short pieces of conduit can be used for physical protection without complying with the rules for a 'conduit system.'

Other than protecting the cable from the sharp ends of the conduit nothing else is required.



That is just a sleeve, that is allowed.
Link Posted: 9/12/2011 2:52:42 PM EDT
Google Port-a-mole....I rented one from a locale tool rental place and drilled and placed a 3" drain pipe under my driveway. Pretty slick, still muddy though.
Link Posted: 9/12/2011 3:26:30 PM EDT
Originally Posted By Delta:
Water pick

Take a garden hose with a jet stream adapter and a piece of PVC and burrow your way under the sidewalk, very simple and effective, unless you are afraid of getting muddy but it will work.


this works well.....
Link Posted: 9/14/2011 4:45:55 AM EDT
I used the water jet method to install irrigation line under my driveway. Home depot sold the kit at that time in the irrigation section.
Link Posted: 10/3/2011 10:40:42 AM EDT
Originally Posted By jacassc:
Drive a piece of 3/4" emt conduit. Smash one end, then cut it on an angle to make a point. Lay conduit in trench leading up to sidewalk and pound it home. When it pops out on the otherside cut off the end and push UF wire thru...you may want to install 2 insulating bushing on the conduit ends afterwards to protect the wire from the conduit edges. I've done it many times before

Not exactly the same but I recently finished doing this

Pic 1

Pic 2

Pic 3

Pic 4



Quick update

I completed about 90% of the project yesterday myself. Ended up going the "flatten the end of the metal conduit, pound it across" approach. Went much easier than I thought it would.

First I trenched on the side I need to lay the conduit in and its the same path the line needs to follow to the lamp post anyway, so no extra work. At the crossing point the sidewalk is just about 5' wide so I purchased a 5' piece of 3/4 conduit when buying the wire and the PVC conduit. Flattened the end, didn't cut to shape the tip, layed it in the trench and used a hand sledge to start it. Went in very easy. Then once it was started and aimed in the right direction I used the 8# sledge. Minor flattening of the open end, but not deformed much. Was able to drive it across the 5' in about 10 min with one break to tell wife and kids "watch daddy be a tough guy"!.

Hardest part was finding the top on other side as there was a bit of downward slope to the conduit and it ended up a few inches lower than I planned for. dug out the hole a little deeper with a hand shovel, got the bi-metal blade on the reciprocating saw and cut the end off.

Finished by laying the PVC conduit, fishing the wire the entire run and prepping the lamp post area for a post. Need to find a lamp post in the next few weeks before the ground freezes, get it set and wired then finally connect the wire to the house service.

Thanks for all of the suggestions. No children, pets or North Koreans were hurt in the course of this project (yet).
Link Posted: 10/3/2011 5:09:17 PM EDT
A piece of threaded steel pipe, with caps on each end, sledge hammer. Down side, you need a trench long enough to lay the pipe in and have room to hit it. Drive the pipe under the sidewalk. If the ends dont unscrew, just cut them off. You can jet under with pvc, but as others have said, muddy mess. Both have their ups and downs, both about the same amount of hassle.
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