Water main, irrigation, then whole house

Hello Experts,

I’ve been lurking on this site for a while now and have learned a lot of valuable information. I’m pretty sure there are enough previous posts to answerer all my questions but I wanted to show my system plan anyway to get some feedback. I live in the Portland Or area and have a rancher that was built in 66. All plumbing is currently galvanized and flow has been dwindling in recent years. I plan on replacing the main from the meter to the crawl space and tying into the existing galvanized over Memorial Day weekend. At the same time I’m going to finish the front yard irrigation system. I put the back yard system in last fall when I re-landscaped. I’m pretty sure I will be re-plumbing the house with Wirsbo pex (old schoolers go ahead and bring your copper comments, I’m open to anything, but cost is a major concern) this fall. My questions:

1. Should I install my backflow prevention right at the tee in the main line or back at my sprinkler manifold?

2. Should I sleeve the PVC that is under the path to my side yard parking? If so with what?

3. I plan on using 1†Wirsbo pex for the main from the meter to the house, comments…

4. What should I sleeve the main with that passes through the footing into the crawl space?

5. Should I move the irrigation supply line farther away from the trees (I’d rather not trench through the middle of my yard but am I asking for trouble with the roots)? Or option 2 is to tee in the crawl space and have no trenching to the sprinkler manifold.

6. If I do a pex home run system should I install the manifolds in the garage by the water heater or in the crawl space?

7. Would a branched system make more sense?

8. My electric service panel is grounded through the galvanized water pipe. After I disconnect it from the meter can I leave it in place so I don’t have to mess with re-doing the ground?

Thanks in advance for your help, and please feel free to critique the entire system. I’d like to share in everyone’s experience before I get started.

J

?s

1. Should I install my backflow prevention right at the tee in the main line or back at my sprinkler manifold?

It makes no difference as long it is before the sprinkler valve manifold.

2. Should I sleeve the PVC that is under the path to my side yard parking? If so with what?

No real reason to do so.

3. I plan on using 1†Wirsbo pex for the main from the meter to the house, comments…

Whatever makes you happy.

4. What should I sleeve the main with that passes through the footing into the crawl space?

PVC

5. Should I move the irrigation supply line farther away from the trees (I’d rather not trench through the middle of my yard but am I asking for trouble with the roots)? Or option 2 is to tee in the crawl space and have no trenching to the sprinkler manifold.

Put it wherever you want to.

6. If I do a pex home run system should I install the manifolds in the garage by the water heater or in the crawl space?

You put the manifolds as close to the final connections as possible.

7. Would a branched system make more sense?

There is no right or wrong. It is whichever you prefer.

8. My electric service panel is grounded through the galvanized water pipe. After I disconnect it from the meter can I leave it in place so I don’t have to mess with re-doing the ground?

As long as it remains connected to the old pipe in the ground. But a dedicated ground rod, or two, might be a better option.

1) The advantage to putting an RPZ or even a pressure vacuum breaker backflow somewhere near the main, is that you can then install all your control valves in underground boxes, using inline valves instead of anti-siphon valves, and you can have multiple convenient manifold locations.

5) If you put sprinkler lines anywhere near a tree, you will live to regret it. The tree roots will eventually cause damage, and it will be impossible to really dig them up for proper repair, so will have to re-route them.

Jimbo,

Thanks for the warning about the roots. The more I look at it the more I think I should tee the irrigation supply line off of the main under the house in the crawl space. By doing this I would eliminate about 100+ feet of trenching. The trade off is I have to drill another hole through the footing so I can get the supply line out to the sprinkler manifold.