The original problem was posted 9/9/10, 8:09 AM, called "Replacing section of lawn sprinkler pipe." It's repeated below. Someone asked that I post the outcome in a separate message. Here it is:
Never underestimate the power of two muscular guys. They were able to snake a new 1" pipe in the same hole as the old one, joining the new with the old with a coupling, with one pushing, the other pulling. They arrived at 2:10 and drove away 2:32. Very impressive.
Thanks, again, to everyone for your comments.
Ray
**************************************************************Original message on 9/9/10:
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 here: