How to install a simple irrigation system

[srobinson]

I was tired of having to water my garden beds by hand (or of my plants dying because I'd forgotten), so I decided to install a sprinkler system in my front garden to save the hassle.  I’ve installed some irrigation systems before, but this was an easy project and perfect for a beginner with no prior knowledge.

Step 1

Measure your garden and make a rough sketch of the area of the garden that you’re designing your sprinkler system for.  Keeping your sketch to a scale makes it the next step easier and make sure you include the location of your tap. *My tap is the other side of my deck, but I'd run a couple of lengths of poly tube to this side of my garden before the deck was put in.

  

Step 2

Roughly plan out where you’re planning on laying your pipe and where your sprinklers will be placed.  I put my sprinkler system in a narrow garden bed, so I ran my pipe down one side of my garden bed and used a combination of quarter circle (90 degree) and half circle (180 degree) sprinkler heads - marked in pink on my sketch.  The sprinkler heads I used (Pope Micro jets) cover a 1.5 metre radius, so I placed them about 1.5 metres apart to get even coverage.  The radius and coverage details of sprinkler heads range by type, but the details are usually located on the back of the product packaging.  

Step 3

I'm only putting in a small watering system, so will be using 13mm poly tube and fittings for this project.  This isn’t an essential step, but poly tube tends to keep its coiled shape once it is unrolled, which can make it a bit harder to work with.  This is easily fixed by unrolling the length you need, placing something heavy (ie a brick) on each end and leaving it in the sun for 15-20 minutes - just to soften up a little bit.  

  

Step 4

To install your poly tube, dig a 15-20 cm deep trench, where you plan to run your line, and lay your poly tube in trench.  Weed mat pins are a handy way to keep your poly tube in place.

  

Step 5

Now putting it all together.  You can cut your poly tube to size using scissors or a sharp knife.  Connecting poly tube is easy – slide a 13mm ratchet clamp over the end of the pipe and then push the barb of the 13mm connection fitting into the poly pipe. 

  

Step 6

The connector is held in place by a single 13mm ratchet clamp, which you can now slide back over the connection fitting and close, making sure the clamp is closed at the end of the pipe (and after the barb of the connection fitting).  The clamps prevent your fittings from blowing off under pressure, so make sure they're put on tightly.

  

Step 7

Connect your watering system to the tap using the tap adaptor, followed by the inline filter and an elbow at the bottom of the connection  (to prevent your poly tube from kinking).  Your connection from the tap should look something like this?

  

Step 8

To install the sprinklers, firstly screw the micro sprays screw directly into the top of your rigid risers. You can do this by hand, but a Pope Punch Spanner (https://www.bunnings.com.au/pope-punch-spanner_p3121358?region_id=116177&gclid=Cj0KCQjw_viWBhD8ARIsA...) makes it a bit easier and can be used to put holes in your poly tube, for your riser stakes, as well. Next, pierce a hole in the top of the poly pipe (where you’d like to install your sprinkler) and screw the riser directly into your poly tube.  Repeat this for all of your sprinklers, remembering to make sure you’ve got good coverage between your sprinklers.

    

Step 9

Sometimes your watering system will form a loop (and will not require an end cap), but if it does, place an end cap at the end of the line.  If you don’t have an end cap, simply fold the poly tube over at the end two times and tape it in place.

    

Step 10

Next, turn on your tap and check your water system for leaks and coverage and, once you’re happy, cover over your pipe with dirt and you’re done!

  

[Carol64]

Hi @srobinson . Thank you for this very helpful and inspiring post. I have just moved to a new house with a blank canvas. Still planning the fruit and veg gardens🙏

[JacobZ]

Hi @Carol64,

A warm welcome to the Bunnings Workshop community.

It's great to see @srobinson's post has been both helpful and inspiring to you.

If you'd like any assistance with your fruit and veg gardens, you might like to create your own discussion with some photos, details and questions. 

I'd be happy to assist wherever I can.

Jacob

[Dave-1]

Afternoon @Gerdener_Yoshi

I like the steps you have gone through trying to sort the issue. I do think the best option is to split the two feeds and time them differently for the water pressure you have. 

How wide is the concrete path you are tring to get a new feed line under? I have used a conduit and a hose (with no nozzel) to clear a path before. Push the conduit in a round 5cm under the concrete amd then insert hose with the water turned on high, push hose all the way in and then slowly force the conduit further under as you go. The water should hopefully eat away at the soil allowing the conduit to go further. Once you have reached the other side (its an idea to put tape around the conduit for the distance you want to travel) remove hose, then run your new black pipe down inside it. Then slide the conduit out over the poly pipe leaving it in place.

You can hopefully then have two feeds from your tap that you can time seperatly so teh water pressure stays consistant. Id also make sure the new pipe is debris free Tho confident with your steps you would be able to tell me much more then I know (I dont actually have a sytem, tho have bought parts for one )

Dave

[Gerdener_Yoshi]

Thanks @Dave-1, I will try this. I think the issue is I’ve maxed out pressure for one line. I had two Holman timers each running a line, one for plants inside my gate, and a second outside my gate. Since buying a third timer and splitting inside my gate onto two lines it’s working fab. The outside single line is obviously still struggling. So yes, my challenge now is getting a new conduit+ pipe under this 2m concrete slab. I have been wondering how I feed a conduit through soil for a long time, so you’ve solved another problem at the same time, thanks! Ideally I’d get a 40mm conduit through to run both, but I think 40mm will be too hard to push through dirt so I’ll go with 20mm. The conduit in the soil has sharp damaged edges, but if I don’t touch it I think it should be ok. Having two lines will running will do the trick.

 

 

I’ll give it a crack with my pressure hose. Thanks so much! 

[Gerdener_Yoshi]

Thanks for your reply @JacobZ. Dave1 has been extremely helpful advising how to get a conduit through. It’s pleasing to hear I’ve covered most bases. This is the tap setup, so yeah I’ve split a few lines but the tap is maxed out so will get creative with the non-maxed out line. I’ve got them set to come on at different times. When I was buying the filter a colleague of your told me I didn’t want the reducer. I didn’t think the reducer affected water pressure, more reduces the connection to the 13mm poly. Is this right? Or have I installed the wrong thing (ie filter/reducer)?

I’ll add a photo so you can see what I mean about running a line along the front (I went back to this set up with the ‘stopper’ to isolate - didn’t mean I was isolating with a tee sorry). I need to add another 2-3 sprinklers to the front line so I can plant the front along to the fence. I’ve held off planting since the set-up is maxed. I’ll get the conduit sorted and run a second line next weekend. I’m digging out a clay garden with no drainage or any way to add a drainage outlet today. I figure digging half a metre down then adding soil plus another 300mm soil high is the best I can do  Much prefer playing with the irrigation ha!

 

 

[JacobZ]

Hi @Gerdener_Yoshi,

It looks like you've purchased the Holman 13mm Pressure Reducer And Filter Assembly, which comprises a pressure reducer and an inline filter. The pressure reducer limits the water pressure to a maximum of 800kPa to prevent damage to the irrigation lines. I doubt this pressure reduction is enough to make any huge difference, it is more of a failsafe than anything else.

With that third line installed, I can't see you having any issues with pressure. Once you can get the conduit underneath the path, I think you'll be good to go.

With your clay garden bed, the plan is solid, but it would be worthwhile adding gypsum to the clay at the bottom of your excavation. If you have plants with particularly deep roots, they may run into trouble once they hit that clay layer, so anything you can do to help break it up while it is exposed is going to be helpful.

Let me know if you have any further questions. 

I look forward to the next update.

Jacob