Cutting trench with pressure washer

[Blue280z]

I had to trench in a power cable to the garage from the house.

I used my gas powered pressure washer to cut a precise 3" wide X 18" deep trench. It was minimal work and mess. No crowbars or shovels were needed.... just a pick-axe with a broad blade.

We have mixed till soil here so large rocks are usually problems when digging holes. With the pressure washer, I just blasted around the rock on all sides and under then I could simply reach in a pick it out.

For initial cuts I used some pipe on the lawn to act as a straight line and guide. I used a 0 degree nozzle and made a few completely vertical cuts along each side of the pipe-guide to cut the sod and soften the soil with virtually no back spray or mud.

You can eventually stick the nozzle deeper in the ground to feel where you cut and the soil loosening.

I just kept passing over the line and the cuts went deeper. After ~ 6 inches of depth were loosened, I moved the guide and used a pick axe to lift and snap the small roots I came across near trees. I then switched to a 25 degree nozzle.

As mentioned above, the big rocks were easily tackled with the pressure washer and just picked out.

The slurry of silt flowed and could easily be pulled out again with the broad blade of the pick axe.


Enjoy if you try this.

 

[Baada]

No joke! That looks like it worked great. Good idea.

 

[sberry]

Good job. I have used them to do this and also to cut holes in frozen ground (hot). Cut a hole in 3 ft of frozen gravel parking lot.

 

[lilredex]

Around here, the city no longer digs on smaller excavation jobs. Say your main water shut off out at the street no longer works and needs fixing. They send in a truck with a HP washer and a vacuum pump. Makes quick work of that job and no mess.

They install a new valve downstream with some kind of crimp connectors.....all under full line pressure.

 

[NUTTSGT]

After making it this easy, you are using conduit aren't you ?

 

[bmxdukie]

Here that is called hydroexcavation.. most excavators are going this way due to so many utilities in the ground.
Great job btw.

 

[theoldwizard1]

The slurry of silt flowed ...

Where did the slurry flow to ?

The clay around here is so dense, the only way this would work is with a large deep hole for the slurry to run to and a trash pump.

Still a good idea !

 

[Screwtape]

After just recently using a pick axe and a trip to the chiropractor to trench across my gravel driveway, I'm a little blown away here.

 

[Train]

We do this at home to find the utilities instead of hand digging. OneCall all comes out and marks the location, then we expose the line using a pressure washer and shop vac. Works like a charm.

 

[theoldwizard1]

we do this at home to find the utilities instead of hand digging. Onecall all comes out and marks the location, then we expose the line using a pressure washer and shop vac.

shop vac ??!!!!!!

 

[tcianci]

After making it this easy, you are using conduit aren't you ?

Nah, He is going to run a PVC air line

 

[Tweeker]

Here that is called hydroexcavation.. most excavators are going this way due to so many utilities in the ground.
Great job btw.

+1

 

[crf731]

Yep. It is a great way of making a trench.

We do more or less the same thing around here all the time when digging holes in the cities, so we don't tear up any of the underground utilities. Just on a much larger scale.

Works in the winter too when the ground is frozen.

Down side to it is that when you are done in your trench or hole, you have to haul dirt back in to fill the hole back up, because everything you sucked out of it went away when the vac truck left.

 

[srvctec]

shop vac ??!!!!!!

That's what I was wondering. A Shop Vac will handle that much/type material?

 

[slip knot]

Throw a Vactor truck into the mix and you've got hydro-excavation. This is a newer trend in excavating in areas with a lot of potential interferences. No mess,no fuss excavating.

 

[Thumper68]

I have been using something like this for years to run cable lines under sidewalks and driveways but instead of using my pressure washer I have a several lengths of 1/2 inch copper with a hose adapter (Think garden hose) on one end and flattened the other with a hammer. Dig a small trench on one side of the obstruction (Need that to run the cable anyway) and use the water probe to clear under the obstruction, insert the pvc conduit and run the cable through.

 

[Ed ke6bnl]

I have been putting off a trench from the house to the 5th wheel for a long time, was going to make a piece for the tractor and dig it, but this look like a good use of my 13 HP pressure washer, I have used water for digging holes in our clay soil which is hard as a rock till it is wet and becomes a slurry.

 

[Blue280z]

Glad to help all!

Nutsgt: Yes I am using 1-1/2" water pipe with Teck90 XLPE #2 copper in it. Overkill but I got a good deal on used cable and it was nicked in a few spots so I want no water headaches.

theOldWizard1: there was a bit of a grade and you can see where the slurry flowed in the photo above. I just scooped out the soft muck with the broad blade on my pick-axe. Some sort of shaping to the pressure washer wand could probably blast the slurry upward.