Sprung a Leak Under the Sidewalk

[NotEnough]

I managed to split an irrigation pipe pounding in a sign. So I got that fixed and was quite a happy camper until I fired it up and found water from an unknown source on the other side of the sidewalk. Went to dig it up, and found some not so friendly ants. A week of putting out ant bait and I finally dug up the other side this moring. All of the pipes look good so I ran that zone and water is coming from under the sidewalk. The sidewalk is just under 4' wide.

What's the easiest way to replace this section of pipe, 3/4 sch40? Digging would be a fair endeavor to clear out 2' per side. I'm thinking about jetting out the dirt. Two things worry me. One, there isn't much dirt between where the pipes are and the end of the sidewalk. So I might be taking out most/all of the supporting soil. Two, there isn't much dirt in Houston.....lots of gumbo/clay so I don't know how effective jetting will be.

Anybody have any experience jetting under a sidewalk??

I have an electric pressure washer, but I'd need to find a short handle/head to minimize tearing up more of the yard.

 

[Chaz]

The broken pipe is usually just cracked. Oftentimes you can glue a section of new pipe to the old pipe and pull it through....
I used to be in the business, and we did this with some regularity. Usually with poly pipe though.

 

[NUTTSGT]

The broken pipe is usually just cracked. Oftentimes you can glue a section of new pipe to the old pipe and pull it through....

If this doesn't work, I'd drive a larger metal pipe under the side walk. Keep taking it out and driving it under the sidewalk to create a tunnel for a new line.

 

[1320stang]

Too bad it wasn't sleeved. When I add onto my driveway, I plan on putting a couple sleeves in for the future.

 

[rburke65]

Don't know......could you cut the piece of side walk, lift it out and then repair, then replace the piece of side walk?

 

[mayday0017]

Buy a jet nozzel from the box store in the sprinkler section. Connect it to piece of PVC and then to waterhose. Turn water on and push it right through the dirt. Turn water off and disconnect everything. Let it sit for a day so the muddy mess goes away. Then connect your lines up. If you don't care about dealing with the muddy mess and you had everything on hand you could fix this in about 5 min seeing that you already have everything dug out.

 

[pop pop]

Mayday obviously has experience! +1

 

[mharmon]

X2 on Mayday.

it is very easy to do. You just need to remember to get the right adapters ie hose thread vs pipe thread.

 

[plumbstupid]

Dig it up on both sides
Cut the line on both sides
Tape new line to old line and pull it thru then clamp,couple or glue in place.
It works better if the soil under the sidewalk is wet.

I pull water lines under driveways all the time. I generally use the backhoe to pull the line, but I have wrapped a chain around old lines and used a come-alng to pull them thru.

 

[SGKent]

The pipe under the sidewalk is still there. When it is removed it will leave a tunnel. Use a flat shovel to cut the grass about 6" wide and 2' on one side and 1' on the other. Take the grass out about 6" deep and set it aside. Set a piece of plastic on the grass next to the slit and dig the dirt down to a couple of inches under the pipe. Cut the pipe with a PVC pipe cutter about 6" from the concrete on both sides. Pull the piece out under the concrete. Lay it alongside new PVC and cut a piece just as long. Push it back thru the hole you just made by pulling the piece out. Use couplings that will slide all the way over the pipe on one side and one that slides only 1/2 way on the other. I am sure you can figure it out from here. Be sure to remove one sprinkler and flush the line before relying on it. If this line is under pressure all the time be sure to turn the water off first.

I just blasted 10' under concrete in clay in about 5 minutes last week. I think you will be fine just using the same hole the old pipe comes out of.

When you are done fill the holes back in, pack them a little and put the cut out grass back on. Water it a little and it will look just like new.

 

[AZ Pete]

If what SGKent says doesn't work (it most likely will), do the "jet" method that Mayday recommends, though in my experience you don't need a jet end, just the open end of the replacement pipe, while the other end is connected to a hose, the water coming through the open end of the pipe will wash the clay or soil out of the way as you push it through.

I have pushed a replacement joint of water line through the hole vacated by it's leaking predecessor, that was buried 5' deep, under my lawn. I have also installed new irrigation lines (pvc) and electrical conduit under walkways by "jetting" them.

 

[NotEnough]

Made a jetting lance and gave it a run. It took a couple of goes b/c I had to keep draining the water out. Also hit a fair bit of **** (concrete chunks and rocks) and lots of clay.

Now I need to let it dry so that can try to figure out which line is leaking. Hopefully it will be the 3/4" line b/c it's on top of the 1/2" line.

Here's a link to a sprinkler supply store who caters to DIY'ers. Gives a pictorial on the pieces needed to put together a lance for those of us who are not as fluent in plumbing parts. You'll probably get a zombie stare from the box store guys, but a picture might get you some help from them. I rented a tone generator on steriods from them last year to find my valves which were burried under crushed granite on the side of my house. http://www.sprinklerwarehouse.com/DIY-How-to-dig-under-a-pathway-s/6560.htm

Thanks for all of the suggestions.

 

[7th Kahuna]

I recently undertook a similar project. I was hesitant to jet because of the clay. Ended up digging in from both sides and then back filling with sand. Often the jetting works fine however. I share the story because I swear the contractor who built the house in 1948 must have been waiting 65 years for his little joke to play out. Dead center, 2 feet from either side of the sidewalk and directly in line between the water meter and house he had dug a 6 inch wide trench paralleling the walk and filled it with rubble. It took me as long to get through that as to dig the rest of the hole. On the plus side I pulled an old ?Model T Pickup? hub cap out of the hole. Wish I hadn't beat on it quite so much with the shovel.

For what it will cost, might I suggest replacing all of the pipes, just in case the damage was done in place, during construction, rather than prior to. No point risking having to dig it up again later.

 

[mayday0017]

Glad to see it all worked out! Never seen a hole that big left from jetting, mine jus ended up the same size as the pipe pretty much. I do know that I couldn't pull it out the next day and slide a new piece through (tried that once).

I would recommend trying to back fill around the pipes some when you get done, not sure what weight load the cement above it sees, but with out dirt under it, you run the risk of it cracking/busting.

Also +1 for using sprinkler warehouse, they are located about 2 miles from my house here in Houston. Excellent people to deal with and best prices anywhere!