Tunneling my electric under sidewalk, need suggestions

[hockey88fan]

I dug a trench today from our garage to our house to run the electrical conduit. It was TOUGH digging with a rented backhoe, very shaley. The 45' trench took a few hours, I thought that was the tough part, but I was wrong. Tunneling the last few feet to the foundation wall is proving to be extremely difficult. I'm working at with picks, shovels, chisels, etc., went about a foot in an hour. I'm wonder if there's any easier way that I'm missing? A trade secret or something. I read online about doing it with high pressure water but wonder if it will work with the extremely rocky shale I'm dealing with, these rocks are pretty big. Any ideas?? Thanks!!

 

[rsanter]

What size conduit?
How about you make a hole saw with a piece of pipe and drill it a little at a time

Bob

 

[Dick in Wisconsin]

Going under the sidewalk, trying "jetting it".

Dig a hole on either side. Hook a hose to the PVC pipe that will be your conduit for the electrical under the sidewalk. Start on one side, get the pipe all lined up, turn the water on full blast, and push the pipe through from one side to the other.

Turn the water off when the pipe emerges.

Let the water drain away while you have a cold one and talk about how slick it went. Unhook the water line. Trim the PVC conduit to fit. You should be good to go!

 

[hockey88fan]

Going under the sidewalk, trying "jetting it".

Dig a hole on either side. Hook a hose to the PVC pipe that will be your conduit for the electrical under the sidewalk. Start on one side, get the pipe all lined up, turn the water on full blast, and push the pipe through from one side to the other.

Turn the water off when the pipe emerges.

Let the water drain away while you have a cold one and talk about how slick it went. Unhook the water line. Trim the PVC conduit to fit. You should be good to go!

I was thinking about this but would it work in shale where some of the rocks I'm dealing with are 10" from end to end. I am going under a sidewalk but ending at the foundation wall, the other side in this case is the basement of my house. This is my dilemma, I can't believe how frustrating it is. I keep telling myself the guys who escaped Alcatraz tunneled thru concrete walls with table spoons and butter knives, just keep going haha.

 

[uniballer]

Bosch rotary hammer drill, use 2" bit. thats all i do! should be using 1" or 1.5" conduit.

 

[hockey88fan]

Bosch rotary hammer drill, use 2" bit. thats all i do! should be using 1" or 1.5" conduit.

Actually running a little more than electric. 2" for the electric run, 3/4" for cable/phone, a 2.5" for future possible running a pex line thru, 3" for possible future sewer. So the hole has to be fairly large, maybe one foot diameter.

 

[mrobins297aaa]

Going under the sidewalk, trying "jetting it".

Dig a hole on either side. Hook a hose to the PVC pipe that will be your conduit for the electrical under the sidewalk. Start on one side, get the pipe all lined up, turn the water on full blast, and push the pipe through from one side to the other.

Turn the water off when the pipe emerges.

Let the water drain away while you have a cold one and talk about how slick it went. Unhook the water line. Trim the PVC conduit to fit. You should be good to go!

i think thats wishful thinking at best......if you have sand, yeah it works great or maybe topsoil it would work, but not rocks or gravel.

 

[Nighttrain]

Use a power washer! I tried for two hours with a mini excavator to drive a steel pipe 5' under a sidewalk in limestone here. Just about gave up when my 12 year old son said "dad we should try the power washer" I said ok. Ten yes ten minutes I was through!!!. Did 3' from each side and made a 6" hole all the way through. It also did not puddle too much since it was not on that long. You said you have some rock in there, I bet you will be able to blast past/around them. Give it a try.

 

[hockey88fan]

Use a power washer! I tried for two hours with a mini excavator to drive a steel pipe 5' under a sidewalk in limestone here. Just about gave up when my 12 year old son said "dad we should try the power washer" I said ok. Ten yes ten minutes I was through!!!. Did 3' from each side and made a 6" hole all the way through. It also did not puddle too much since it was not on that long. You said you have some rock in there, I bet you will be able to blast past/around them. Give it a try.

Thought it might turn into a muddy mess but maybe I'll try since u had such great results.

 

[Torque1st]

I have used a large schedule 40 pipe with a 'T' on the end in soil mixed with gravel and fair size rocks and bricks (back-fill). Screw a plug into one end of the run and your pipe into the other. Use the appropriate bushings/fittings to connect your hose to the branch. Use a small sledge to 'drive' the pipe through with the water on full force. Once you have a hole you can very easily enlarge it using the same pipe.

Remember, you used to consider playing in the mud to be FUN!

Once your pipe(s) are in place you can 'grout' them into place with some expanding foam.

 

[green.bubbly]

How deep are you running the lines? If not too deep, rent a concrete saw and cut a channel through your side walk. The saw would also cut the rocks to the point where you would just need to knock them out.

If you have to go deeper, rent a small jack hammer after you cut the sidewalk out the way.

 

[jtrace]

See if your local rental store rents water drills you hook it up to pipe and your garden hose with a 3/4" drill that comes with it... should go right through it rocks and all...

John

 

[5lima30]

How deep are you running the lines? If not too deep, rent a concrete saw and cut a channel through your side walk. The saw would also cut the rocks to the point where you would just need to knock them out.

If you have to go deeper, rent a small jack hammer after you cut the sidewalk out the way.

+1 being its rock/shale^^^^^!

 

[theoldwizard1]

Pros would have started with a concrete saw and then some type of jack hammer (HD rents small to big ones).

If the side walk your are going under is not more than about 4' wide, you can buy a concrete blade for your circular saw. It will take multiple passes, cutting about 1/2" at a time. The dust will be huge ! Be careful to not overheat the blade.

You probably don't have to get the blade to go all the way through the concrete to the dirt. After getting the saw cut 2-3", deep break out the jack/demolition hammer !


The only reason for the saw, is so the cut looks nice when you patch it back up. If you don't care, skip the saw and get a bigger jack hammer ! It will take more concrete to patch it up !!

 

[hockey88fan]

Here's a pic of the trench and the tunnel im trying to dig, all the while trying not to disturb the stamped concrete patio and sidewalk.

 

[signcrafter]

I used a pressure washer to do similar in clay/stone earth. It worked great. Blast for a minute then let stuff run out and clean out the hole. Keep doing this and you will be through in no time. If you hit a big rock you can blast around it until it can be taken out.

 

[GarageEnvy]

I've done the water pressure routine and it worked great but I've also had some tough spots like your where it wouldn't work. For a short throw like that I took some old 2" galvanized pipe and cut/ground the end jagged. I crossdrilled a hole in the other end for a piece of rebar. Then I pounded on the pipe and wiggled/rotated it with the rebar handle. It was slow and a completely hillbilly solution but it did work. You can definitely skip the gym that day too.

 

[kbs2244]

Check this out.

http://www.borzit.com/

 

[theoldwizard1]

Here's a pic of the trench and the tunnel im trying to dig, all the while trying not to disturb the stamped concrete patio and sidewalk.

I understand your concern, but what is going to happen to the sidewalk when the tunnel eventually caves in ?

Can you put a 6" pipe in there ?

 

[Torque1st]

I understand your concern, but what is going to happen to the sidewalk when the tunnel eventually caves in ?

Can you put a 6" pipe in there ?

Collapse is what a large pipe and expanding foam prevents.

 

[premierplayer]

line boring rods and bits, the tractor you rented may have a take off shaft. you can go up to 36" bits with the right equipment pushing them

here's a demo on a little smaller scale
http://www.youtube.com/watch?feature=endscreen&v=E95mfqkCm2M&NR=1

 

[bczygan]

Sawcut a portion of the sidewalk with a diamond blade both sides using existing joints as much as possible. Carefully lift and remove. Dig trench and install pipes and wires. Backfill and compact fill material. Set removed piece in cement bed. Caulk joints.

 

[hockey88fan]

I understand your concern, but what is going to happen to the sidewalk when the tunnel eventually caves in ?

Can you put a 6" pipe in there ?

I started digging from the basement towards the trench thinking it would be easier because it was chest high, and it was. I've got about a foot to go to meet the tunnel I started on the outside. Here's the problem, wouldn't you know it we got a thunderstorm this afternoon, wind blowing from the north, which is rare here, blew rain against the side of the house I was working and now the trench is collapsing on the basement hole side. Not sure how I'm gonna fill that void.

 

[Herb]

Ask Danny, he'll know!

 

[KCarGuy]

I had to run a Gas line from my House to my Garage and ran into the same situation.
I had to go under a concrete sidewalk.
I welded up my own "Large" Spade Bit with a 2 foot long 1/2 Solid Rod.
The 4" Spade curved in slightly to pull dirt and stone away.

It worked perfectly and I was able to Run my 1/2" corded Drill through Dirt, Clay, stone and Roots pretty quickly. Just stopping a few times to clear out all the loose stuff before drilling again.
Then Ran some 2" PVC with my Gas Line Through that and filled the rest with Expanding "Pond Waterfall Foam" before filling the trenches back up.

 

[hockey88fan]

We have daylight

 

[barks]

I give up. What are the counting marks on the wall above your hole?

 

[premierplayer]

I give up. What are the counting marks on the wall above your hole?

that's how many day he's been working on it with a spoon from the mess hall

 

[rodm1]

 

[hockey88fan]

I give up. What are the counting marks on the wall above your hole?

How many 5 gal buckets of dirt I hauled out.

 

[hockey88fan]

that's how many day he's been working on it with a spoon from the mess hall

Lmao feels that way, started digging Thursday, broke thru Saturday morning.

 

[hockey88fan]

That is slick! But wouldn't get me an inch in the shale I was dealing with.

 

[bobemmerich]

Ask Danny, he'll know!

LOL..."The Tunnel King" One of my favorite movies! R.I.P Charlie.

Glad to see it worked out.

 

[hockey88fan]

Thought I'd update, here's the finish product. Took multiple layers of mortar and pieces of brick.
Also just watched The Great Escape with Danny the tunnel king, great movie.

 

[CreekWV]

Looks good! Glad you got through. I've done a couple of those around my house and it can be frustrating.
For future readers, i did a blind 30' bore from the basement of an outbuilding to a pit under the main house with a Borzit device and a Milwaukee hole hawg. Went under two walls and 15' of blacktop. Drilled it with a 2" bit, pulled back out, and then hammered 1.5" pvc back through the muck as a sleeve. Material was hard clay and rubble, so i didn't progress as fast as the website said i would, but I did make it. I had tried and failed with homemade pressure washer rigs, hammering steel pipe, garden hose, and other methods.

I've also use a bulb planting auger underneath a sidewalk with good success, and before I bought the Borzit i rented a similar device from the local rental yard that used a gas engine motivated bit, a water hose, and pulley system to drill/push under a driveway. it was in such poor repair that I spent more time coaxing it into action than actually drilling, but when it actually ran it worked well.

 

[Nighttrain]

Great job, I know how hard the digging was. Glad your done with it.