Notat Home wrote:
Rebel1 wrote:
I have to replace about 20 feet of 1-inch black poly pipe between the
house and the five-zone manifold. About six feet of the pipe passes
under a paver brick walkway, which I don't want to disturb. The pipe
is about 6-8" below the soil, in Central New Jersey.

The first sprinkler company I called said the walkway must be
disturbed, and it would be up to me to make arrangements to remove
and restore the pavers. If I tackled that job myself, then I could
easily replace the pipe as well.

The second company said he would simply pass a 3/4" section of pipe
through the existing 1" pipe under the walkway, then use adapters to
transition back to 1 inch. (I don't know if meant to make the entire
run 3/4" or just the part passing under the walkway. He's looking
over the job tomorrow.)

I asked about the reduced flow available through the 3/4" pipe. He
said that as long as I don't have more than five sprinkler heads on
a zone, I would be okay. My heads are all pop-ups, mostly rotaries
by Hunter, but a few non-rotaries, and there are only five per zone,
so it sounds okay. One site says that typical head delivers 1/2
gal/minute, so with five per zone, that's 2.5 gpm, well below what a
3/4" pipe can deliver (about 23 gpm).

Any comments on using 3/4" pipe, or other suggestions for not
disturbing the walkway? One website suggested blasting a hole using
full-force water through a garden hose. Other suggestions are he
http://forums2.gardenweb.com/forums/...341731539.html

Thanks,

Ray
If the walkway is properly built, there is probably a layer of gravel
under it (possibly some gravel caused the leak) so you will have to
deal with that, probably by going under it.

I had a similar situation. I bought some PVC and cut some teeth in
one end. Using a strap wrench, a sledge, a garden hose (I ran this
into the pipe every few minutes and used the water to erode the
dirt), and some creative languaqe, I got the PVC to the other side of
the sidewalk. I left the PVC in place to help support the sidewalk,
and easily slid my poly through this tunnel. I used 2 inch PVC as it
seemed stronger and would take the twisting and hammering, and would
easily hold the one inch poly.

To install PVC well points, I used 2" PVC with "teeth" as you described, with an
adapter on one end to attach 2 garden hoses to (for extra volume). Turn on the
water and push/twist the pipe through the ground. The mud runs out alongside it.
It took me maybe 15-20 minutes to run the 2" PVC down 15 feet in my sandy soil.
YMMV. For the OP, you'd need enough ditch to get the PVC down to the level under
the walk and gravel, and to hold the mud/water that comes back out.

Hardware stores carry a blaster kit with a nozzle and female hose fitting for 1"
PVC pipe.