Installing sprinkler shut off valve below frostline
I'm attempting to put in a sprinkler system in Northern Utah where the frost line is approx. 36" below ground.
The house is around 30 years old, and at one time there was another sprinkler system in place by the previous owner, but it has long since eroded so I'm basically starting from scratch.
The water main comes in to the house and is buried about 36" below ground. The old owner had his sprinkler system tied into this main about a foot back from the house, and all that was remaining was a plugged 3/4" tee. So that is my water source.
I've dug down to the tee, and attached some pvc to run up to ground level with a ball valve as my sprinkler shutoff valve, and that's where I'm at now.
I'm thinking that this isn't going to work, because it will freeze and break in the winter. Am I correct in assuming that, and if so, is there a way to keep this from happening? Could I put the shutoff valve in a valve box 12" below ground, or would I need to install a valve 3' below ground? How is this normally done?
Thanks for any help.