Boring Under 6' Sidewalk With Pressure Washer.

[GoldDigger]

I have used same method in sandy soil and went maybe 50-60 feet with 2 inch PVC before. You need to use same pipe you intend to leave in place in that kind of situation as it likely will not pull back out.

While you are actively boring, the flow of water is coming back under some pressure along the path of the pipe, keeping the fill from settling and lubricating the outside of the pipe.
Once you break through at the other end this effect stops, so either pulling back or advancing the pipe further will become very hard.
And once you let things settle and the water in the fill around the pipe drains away, you will find the pipe very well locked in place.

 

[kwired]

While you are actively boring, the flow of water is coming back under some pressure along the path of the pipe, keeping the fill from settling and lubricating the outside of the pipe.
Once you break through at the other end this effect stops, so either pulling back or advancing the pipe further will become very hard.
And once you let things settle and the water in the fill around the pipe drains away, you will find the pipe very well locked in place.

pretty much what happens from my observations - especially in loose soils like sand.

 

[roger]

Hi Roger
I always use 3/4 GRC. Have a set up I made from Lowes. 3/4 ball valve with a NPT to hose adapter and a 1/4 jet nozzle with NPT to hose adapter on the other end. Just screw it onto the conduit and wash it under the sidewalk. When you get through just remove the valve and nozzle. Just dig the hole deeper on the side you start from to catch the water.

Hey Curtis. I used to always keep a NPT to hose adapter in my truck, I never got around to adding the other parts though.

Roger