On Wed, 25 Jan 2012 17:56:28 -0800, Bob F wrote:
If they are subject to freezing temps,
you will have to take that into account.

It's the Silicon Valley, so, it doesn't really get to freezing
temperatures (all that much). The house is 30 years old so I assume the
pipes never froze before.

They seem to also have a buried wire (looks like low voltage but I'm not
sure) next to them. (Too dark now but I'll snap a closeup tomorrow.)

They were covered with sod which I dug up to in the process of digging a
couple of inches down to start putting the flagstone walkway in.

I'm surprised they had no cover on top; just sod.

I guess I 'could' just put a flatstone on top of them - but that seems
not to be the right way to do it.

I'm gonna look for a double-width irrigation box - but I wonder if there
is something made for this. There are no valves, so I don't really need
access to it. They're just PVC water pipes which were about 2 inches or 3
inches below the top of the sod.