boring under a driveway??

[bimmer1980]

has anybody on here ever bored a hole under a driveway or sidewalk for conduit? I've got some ideas on how to do it, but I'm interested in feedback from guys that have actually done it.....

I need a hole large enough for at least a 2" electrical conduit

 

[CraigFL]

I haven't done it myself for a long run like that but I've used water pressure for short runs.

 

[babzog]

Here's one way to do it.

 

[thammel]

Yes, I've gone under sidewalk for even larger than 2" conduit. I've run 4" black flex drain line under.

The pvc might work but if you've got stones it'll probably break. What I've done and see others do is to use metal pipe or conduit. You will need a sledgehammer for sure to drive it. And go a few - maybe 6" and then pull it out or it'll get stuck snd you might have a hard time getting it out. I probably also used a digging bar and ended up digging a fairly big hole. Don't expect it to be an easy job - remember I only went about 3 to 3.5' across the width of a sidewalk.

You've probably seen how the pros do it with those big machines that bore under streets. I think you probably don't want to pay someone to do it!

Tom

 

[Costner]

I'll tell you what I have seen done and it worked pretty well. Take a 2" piece of PVC and pound it in a few inches. You might want to just hand dig the first one or two feet so the pipe has a "pocket" to rest in. Then take a rigid piece of copper pipe (or any rigid pipe for that matter) which has a cap on the far end. Drill a small hole in that cap and then hook the other end to a garden hose. The water pressure from the hole will soften and blast away the soil inside of the PVC which will then run out inside the PVC.

Then it is just a matter of continuing to tap the PVC and continuing to move it forward. The water also acts like a lubricant to make it easier to advance it in the hole.

Not sure how easy this would be for an extra wide driveway, but assuming your soil isn't full of rocks and you can keep the pipe straight it would work ok. The one negative is you need to have a trench on your starting side at least as long as the pipe you use plus a few feet to swing a hammer, so if you were using a 10ft section of pipe you would probably need a 12 foot trench to start with. You also would be wise to dig a little pit where you are starting so the water that runs out has a place to go - otherwise you will be dealing with a mudpit the entire time.

 

[A_Pmech]

Got a pressure washer?

 

[hguerrero]

how would you use the pressure washer?

 

[A_Pmech]

They actually make boring heads for use with a pressure washer. However, those little nozzles that have a single focused jet work well too. I've heard the "turbo" spinning nozzles work really well, but I've never tried one.

Put the pressure washer wand though the center of the conduit and blast away. Push the conduit forward as you blast.

Wear a raincoat.

 

[bhays]

I did this last year. Just get a fitting to glue on the end of pvc with threads for a garden hose. Then put a cheap nozzle on the end, same fitting on the other end then hook up the hose. The water will drill the hold ahead of your pipe like magic. When you get a length of pipe all the way in, stop and use a couple to glue on another, then repeat.

Some building supplies have 20' lengths of pvc so you might be able to avoid that step. Works like a charm, you will be through in no time.

 

[Bustawrench]

Rent a pneumatic mole for a day. Job will be a piece of cake.

http://www.redwoodrental.com/moles.html

 

[nonhog]

Reant a pneumatic mole for a day. Job will be a piece of cake.

http://www.redwoodrental.com/moles.html

If its soft use water, if rocky use the mole.
I just went under my sidewalk (3rd time and the worst) lots of rocks.
Combo of sore arms and shoulders and 5' bar, a shovel and water power.

 

[walrus]

If its for conduit make sure you are down 2 feet or more.

 

[tcianci]

I recently drove an 1 1/4 inch pipe under a 15 foot wide driveway. I put the bull point of a pavement breaker into the front of the pipe and drove it with a sledge hammer. Took a few hours. One word of caution: Any "digging" that involves removing the pipe and the soil contained in the pipe could eventually lead to settling. For instance, If you somehow tunnel under the driveway and then feed a pipe through, you don't necessarily have the entire void you created re-filled. It will settle eventually, possibly damaging the pavement.

 

[Chris Adams]

All interesting answers but the real question is what is under the driveway?

I have seen solid rock. You ain't going through that.

We have something called calichi clay under a lot of the desert. With a mattock and a pick you can penetrate it as easily as hard concrete...
You won't be driving plastic through it. Probably not iron pipe.
I used a steel spike an inch thick and a sledge to penetrate ten inches of it a few years ago. Took all day to punch a two feet deep, one foot hole. I mean from sun up to sun down.

Soft loam, loose sand, farming soil you can dig a hole on each side and drift a PVC pipe through it in minutes.

Do you know what soil/rocks etc. is under there?

 

[T VETTE]

Yes, I've gone under sidewalk for even larger than 2" conduit. I've run 4" black flex drain line under.

The pvc might work but if you've got stones it'll probably break. What I've done and see others do is to use metal pipe or conduit. You will need a sledgehammer for sure to drive it. And go a few - maybe 6" and then pull it out or it'll get stuck snd you might have a hard time getting it out. I probably also used a digging bar and ended up digging a fairly big hole. Don't expect it to be an easy job - remember I only went about 3 to 3.5' across the width of a sidewalk.

You've probably seen how the pros do it with those big machines that bore under streets. I think you probably don't want to pay someone to do it!

Tom

I just went under a 3' sidewalk and needed to put a 3" drain pipe under. I agree on task listed. Glad it is over.

 

[bimmer1980]

I originally got the idea to drive it under the asphalt drive after seeing Paul Bird's lift install. I think it is fairly soft clay-like. I have the rest of the back yard torn up from digging out stumps. It is a greasy dirt when wet..... I'm planning to bring a mini-ex in to dig on either side of the drive way, so that will be the determining factor...

for what it's worth, the local home depot has a mole for sale... they "only" want $2700 for it... it was $3400. It is left over from a display demo they had and are trying to move it.... I told the guy I would give him a couple of hundred bucks for it... he thought $1k to 2K would be pushing it.... regardless, that would be the ticket!
http://www.portamole.com/

Yeah, I have seen the directional line boring machines--they are slick. At my last job I contracted a few companies to do that work---one time they hit a water line--that was entertaining!!

thanks for the input guys!

 

[79firebird]

When i have had to go under sidewalks and driveways i went to the local muffler shop and grabed some pipe from there scrap bin to bash thru the dirt. works good. and was free. then i ran pvc in it.

 

[Clik]

X2 on washing it through. I've done it many, many times. If you have really rocky soil, many rental places rent impact/vibrating moles.

 

[Garage5.9]

Sorry im of no help but depending on the size of the hole this could work

 

[KCarGuy]

I needed to go under a Sidewalk section to run a Gas Line.
I welded up a Makeshift Drill.
I welded a 3 foot Metal Tube over an old Half inch bit (for my 1/2 Drill)
and in the end welded and bent a steel plate that would cut into and push out the dirt, clay and stones. (it made a 2" Hole)
Because I already dug a trench leading up to the sidewalk, it was easy to lay the drill down and simply "walk it" right on through.
Only stopping to clean out the excess dirt-stones.
I was lucky though, I didnt run into any big rocks.
Pushed my 2" PVC through (just for under the sidewalk) and then ran my Plastic Yellow construction tubing that Held my Gasline inside that from house to garage.