# Laying underground conduit?



## Hyatt (Aug 13, 2019)

Hello there,
A job to install pavers/interlock on my property is about to begin, and I wanted to add an irrigation system. Currently, I primarily use drip irrigation for front and backyard plants, but it's all exposed above ground. I'd like to expand the drip system (additional landscaping), as well as incorporate irrigation for the lawn (roughly 20x10), and put as much as possible underground. The PSI of my city water at the exterior faucet is 55.

I'd like to put in conduit and run the line through it instead of burying it directly so I could replace/add in the future. Since these will be below pavers, it's not as easy to dig up as sod/dirt. I'm also OK with using regular hose faucets instead of underground main (its not a big property), and both faucets I intend to run from are close to where irrigation is needed (side of house and rear of property).

1. Are straight conduit paths the only way to lay it down? I imagine any 90s will result in kinks to the line. Are there 45degree conduit connectors? How best to handle corners?

2. How feasible is it to insert a new line/low voltage/etc after the fact? Or replace an existing line if leaking?

3. Is the conduit completely underground and only the irrigation line goes above the surface? I can understand how to access if I need to when it terminates in the soil/garden bed (dig it up), but how does the access look like when surfacing above pavers? Do you also surface the conduit straight up, similar to how cable is in modern subdivisions? Should the conduit be capped to prevent dirt and rodents to enter?

4. Is 3" conduit sufficient? I'll essentially have 2 maybe 3 zones in the front (3 beds, all similar watering needs, and the lawn). I understand the lawn would require larger main than the drip. The back is 2 zones, again similar watering needs.

5. Is there a sprinkler head best suited for rectangular lawns? Is it feasible 1 or 2 heads could accomplish what I need? It's not a large patch of lawn.

Is there anything else I should know specifically regarding the underground conduit? I've tried to search and didn't find much. I found resources about adding conduit after the fact, but that's not relevant for me (the ground will be open for the pavers so I have full access).

Should I run some low voltage wire with the irrigation lines, even if I don't plan to put in lighting right now?

Thanks!
Hyatt


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## hsvtoolfool (Jul 23, 2018)

Do you intend to run the drip line in conduit? Maybe I misunderstand, but it sounds like you're going at this backwards.

Run 1/2" schedule 40 PVC pipe to each location where you'll use drip irrigation. In other words, run the water to the plants and then convert it to drip irrigation.

That's exactly what I did for my mulch beds. I stubbed out 1/2" PVC above ground in each mulch bed. They're all on the same zone valve. Once my plants were installed, I then cut the PVC pipe off at ground level, installed a 90° slip-thread elbow, screwed in a "barb" fitting for 1/2" hose, installed a 150 mesh filter, and then connected up and buried the Rainbird drip line. Easy peasy. I can also easlity replace the drip line with drip emitters or mini-sprayers anytime I want.


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## Hyatt (Aug 13, 2019)

Yes, my intention was to run lines IN the conduit.

I've already had a couple family members who experienced leaks and they had to open up the ground to find the source. I was hoping to use the conduit in the same way you put conduit in a house to add/replace Cat cables, etc without having to break walls. If there was ever an issue with the main lines, I could replace/add without having to dig anything.

Not sure how common that it, how to address corners, etc

It would be like a pathway for the tubing where it's not practical to dig up (so when it crosses the interlock paths, as well as along the house with interlock, etc).


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## jayhawk (Apr 18, 2017)

https://www.homedepot.com/p/JM-eagle-3-4-in-x-10-ft-PVC-Schedule-40-Conduit-67454/100129197
Conduit like that, many sizes and fittings. There are 45 and 90s ....two 45s are more graceful. If you put together 30 feet straight....you can bend it around the house corner if try. Also, there ways to heat it up and bend (takes patience) but the fittings are cheap enough so I wouldn't bother.

I do run conduit inside and outside (to protect irrigation wires, avoid having the cable guy touch the yard)


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## Hyatt (Aug 13, 2019)

jayhawk said:


> https://www.homedepot.com/p/JM-eagle-3-4-in-x-10-ft-PVC-Schedule-40-Conduit-67454/100129197
> Conduit like that, many sizes and fittings. There are 45 and 90s ....two 45s are more graceful. If you put together 30 feet straight....you can bend it around the house corner if try. Also, there ways to heat it up and bend (takes patience) but the fittings are cheap enough so I wouldn't bother.
> 
> I do run conduit inside and outside (to protect irrigation wires, avoid having the cable guy touch the yard)


Thank you.

Where the conduit starts/terminates, is it completely underground or do you also create a graceful 45 degree upward so that part of the conduit is above the surface?

I can understand burying where it terminates because it would be near flower beds, dirt, etc (easy to dig up), but what about where it begins near the outdoor faucet? Where I live the side of the house where cable/gas/etc enters the home, there is also a vertical conduit that surfaces above ground. Wondering if I should do that as well or just fill that spot with gravel and surface the rough lines only.

I'm trying to visualize how it would look when the tubing surfaces through hardscape like interlocking/concrete etc.


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## hsvtoolfool (Jul 23, 2018)

Hyatt said:


> Yes, my intention was to run lines IN the conduit.


You haven't said the total length for these conduit runs (I apologize if I missed that number), but I wouldn't attempt anything over 5 or 6 feet. My advice is to keep all the drip irrigation line short as possible so replacing it every few years is cheap and easy. That's why I'm trying to get you to run the water into the beds, then switch to drip right at the plants.

Drip lines are fragile, aren't designed to last, clog easily, and replacing them will be an expensive nightmare. I suspect you'll have to re-pull ALL the lines in the conduit each time ONE line leaks. They'll likely get tangled and break off inside the conduit, which is a nightmare. There's also the risk of inadequate pressure and flow if the drip line runs are too long.

In contrast, schedule 40 PVC lasts decades. Glue it up, bury it once, and you're done forever. It's easy. You can use one valve for all your drip irrigation, or you can split them into separates zones as needed. You'll likely need to install a filter and pressure reducer inside each mulch bed depending on what your drip irrigation gear requires. I was able reduce the pressure to 30 PSI using one adapter just after my control valve (for all my beds) since the Rainbird drip line handles up to 60 PSI. But those small drip emitters and mini-spray heads are rated at much lower pressure. But I still put a 150 mesh screen in each bed and flush the screens and drip lines each Spring. I only takes a few minutes and prevents clogging.

My attached photo will hopefully make my poor explanations clear. Notice in both photos I also stubbed out low voltage wire in all 5 mulch beds. Hey, the irrigation trench was there so why not use it? I still haven't installed the lighting 2 years later, but I can do it any time I want. I hope this helps!


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## Hyatt (Aug 13, 2019)

hsvtoolfool said:


> Hyatt said:
> 
> 
> > Yes, my intention was to run lines IN the conduit.
> ...


Thank you for the pics and the explanation - while a picture says a thousand words, your description was equally clear! 

It seems I'm unclear however. Lol. So I actually agree with you, I didn't want to run drip irrigation tubing underground in the conduit (sorry if it seemed that way, I'm not good explaining this). What I actually was thinking was similar to what you described and pictured, but instead of having that 3/4" pipe as your main water line DIRECTLY IN THE GROUND, I would put that 3/4" pipe through a larger say 2-3" conduit, and put both into the ground. These runs are anywhere from 10 to 20 feet.

So while I would have the central or main line as you described (and branch off to drip tubing in the beds themselves), the idea was to give me the possibility to replace the 3/4" main line without having to dig up and remove interlock stones if it sprung a leak or cracked or was eaten by a rodent etc.


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## hsvtoolfool (Jul 23, 2018)

Hyatt said:


> What I actually was thinking was similar to what you described and pictured, but instead of having that 3/4" pipe as your main water line DIRECTLY IN THE GROUND, I would put that 3/4" pipe through a larger say 2-3" conduit, and put both into the ground. These runs are anywhere from 10 to 20 feet.


I understand now. That makes more sense to me. But I think you're worried about nothing. Sch 40 PVC pipe is really tough. So long as your glue joints are done correctly, I wouldn't worry about leaks or varmints. I'd keep it simple and just run 3/4" PVC pipe where you need, then switch over to drip irrigation locally.

Now having said that, I planned ahead in my front yard and installed 6-inch PVC pipe in several places and then capped it off so dirt and water couldn't get in. This was just a "bridge" allowing me to easily cross barriers later. For example, I hand dug a trench before my driveway was poured. I then installed a 6-inch pipe, stuck in a 1" line and a couple 3/4" lines for future use, and then capped the big pipe to keep out dirt and water. That was extremely handy when I finally installed my irrigation. Save me a ton of work later.


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## Slim 1938 (Aug 24, 2019)

Another suggestion is to run pex line. Its flexible and you can run it in a larger diameter pvc.


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