Trying to tunnel a 2" PVC pipe underground - hit a road block

[MiamiCuse]

I am thinking of adding a sink to the kitchen island - I don't have to do it, I have a kitchen sink by the wall, but thought I would add a sink if it can be done relatively easy when everything is gutted in the kitchen.

I have already cut a 9' long 4" wide trench for the electrical conduit that will run below grade to the nearby wall. I have hot and cold water supply on that wall that I could easily run to the island. All I am lacking is a drain line.

The nearest drain line is now exposed in a bathroom behind that wall. Not directly behind, because there is a hallway in between. The main drain is there, slab is already cut open, I can tie in there and no need to cut any more slab.

So I tried to use the water jet approach, down here in Miami the soil is very sandy. I got a 2" PVC pipe and hooked up a garden hose and glued that to it's tail, glued a cap on the front and drilled a few small holes. turned on the water and the pipe went in slowly. The bathroom tremch gets flooded easily from the jetting water so I waited for it to drain and tried again. However about 8' in I am stuck and it won't go further. It seems to have hit something. I don't know if it may be a grade beam, some large rocks or something else. I have no idea.

I then cut the pipe and ease out the 2" PVC pipe, and inserted just a 1/2" metal EMT pipe into the cavity. 8' in the same result, but I have no idea what that is. I think if I know what it is, I have a fighting chance to solve the problem. If it's a grade beam I will just give up. If it's something else I might try to pass the PVC pipe using a different angle to avoid that obstruction.

I know plumbers have this mini camera lens they attach to the tip of a flexible hose they pass down pipe to see what is going on, I called a plumbing locator service company and they quoted me $1000 for a camera location and told me more than likely it will not work because I don't have a pipe to feed the camera.

Can you think of a economical way to determine what is the obstruction? It's only 8' from the trench and I have a straight shot.

Thanks in advance,

MC

[Speedy Jim]

My, you are determined.

Look on eBay for IR cameras. Like: Item # 320302138280 Less than 2" diameter and has LED illumination built in. And waterproof. Use it for security outdoors after the tunnel is finished...

Hundreds more, that's just an example.

Jim

[Roger Shoaf]

You might have some luck if you take a hole saw and epoxy it to a length of pipe. You can then chuck the pipe into a drill and see if you can cut through the obstruction. Even if the saw doesn't cut, you should get an idea of what is blocking the way.

[Wayne Whitney]

Try a few more places. Here in the Bay Area they are common enough that you can get your sewer lateral scoped for $50-$75. As for the lack of a pipe, you can just reinsert your 2" pipe to carry the scope. You could also try to find a rental place that carries the scope.

Cheers, Wayne

[N8N]

Ridgid sells a scope for about $250, a friend has one and was just speaking very highly of it.

nate

[RLM]

Let it dry out and use a shop vac to tunnel. I have put plastic conduit under a driveway in Pinellas County this way. Put in fence posts also. Use a tarp to empty shop vac on. Use short strokes with shop vac to keep from clogging.

[gfretwell]

In South Florida they usually just pour over the sand, no stone. They may have some junk in there tho.

[Pat]

When you measure 8' do you end up under a wall? I would probably open up the floor and deal with whatever.

[MiamiCuse]

I don't want to cut through whatever in case it may be something like a 4" PVC drain line.

[MiamiCuse]

Think about it and you might not need a camera. You have a poured slab so you know that it is generally compacted stone unless someone PUT something else there. So figure out what someone would put there. You can be pretty sure it isn't a small Buick or anything like that.

You said there's a hallway between you and the drain. Often there's a slump in the concrete there to support the additional weight. That could stick down 6 or 8 inches.

Otherwise, it's a pipe or something -- anyway it's something that you can't move.

Your only choices will be to drill through concrete or go under plumbing. You might have to go deeper.

Pat.

I cannot go deeper because the main sewer elevation passing through the spot I am tunneling governs the minimum elevation on the downstream side of this pipe. The only vairable I can play with is to not shoot in that angle and hope that another angle will avoid that obstruction.

I do not believe there are any drain lines in that area, I have located all the drain lines and they do not go near that area. The only pipe that may be there is two 1/2" copper lines that do go underground, but as to where they travel I have no clue I only know the manifold on both ends of them. However if what I hit are copper lines, then inserting a much thinner 1/2" EMT pipe should have avoided the pipes as I tried to finess it through.

If it is indeed a hunch in the concrete then I am out of luck. My only hope is that it is some sort of debris or rock and if I adjust my angle by 15 degrees I will go pass it.

I sort of have a feeling I would run into this before I started.

[gfretwell]

I am betting on a rock or chunk of concrete that got buried under the slab. When I shot a pipe under my driveway I had the same problem. Fortunately on that shot I had the flexibility to move over a bit and go again. I got lucky going under the garage and went straight through. How low are you? You might have just hit a low spot in the pour if the pipe ramped up too fast. It could even be a grade stake, a piece of rebar they drove in to establish the top of the pour while they were raking the concrete in. They usually just drive them down before they float it out.