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!

  

[EricL]

Hello @srobinson

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thank you for sharing your irrigation project with us.

Thank you for sharing those step-by-step photos of your project. I totally agree that you should plan your irrigation system out before you purchase anything. Knowing the angle and distance of the spray is vital in planning out your irrigation system. It prevents you from putting in too many sprayers and gives you an idea of how much pipe you'll need to layout for your system. 

Again, thank you so much for sharing your fantastic irrigation system.

Eric

[Jason]

What a fantastic and comprehensive first post @srobinson. It's terrific to have you join the Bunnings Workshop community and jump in and share your knowledge and experience. We are looking forward to reading more about all your projects and plans around the house and garden. 

Thanks for sharing this guide, I'm sure our members will find it very useful as they prepare for the warmer weather on the way.

Jason

[KatieC]

Hi @srobinson,

This is such a fabulous guide to a simple irrigation system! I am a novice at this and my husband and I are looking to put in rainwater tanks at our new home, is it possible to connect this system to the tank? I assume we would need a pump for it?

Katie

[srobinson]

Hey @KatieC 

Thanks for that!  I've never done it myself, but it can be done, as long as you used a pump (as these types of systems won't usually work off a gravity fed water supply).  Good Luck!

Robbo

[KatieC]

Thanks @srobinson (Robbo), will let you know how we go!

Katie

[shapi]

thank you- very helpful!!!!

[MitchellMc]

Hi @shapi,

I trust @srobinson will be pleased to hear that you found their guide useful. If you are looking for further information on irrigation systems, check out this handy step-by-step article: How to install a drip irrigation system.

Please let us know if you have any questions.

Mitchell

[Gerdener_Yoshi]

This is great! I have installed the exact same system (13mm poly + 12x 180 micro jets + Holman filter at the outlet). My garden bed is a bit wider @3m. When I started it was a dirt bed and I wanted to grow a hedge. I installed the poly along the back edge of the garden with 12 jets for coverage of 12 bushes, each 1m apart. My microjets only reach 1m (not sure why). 6 months on the hedge is growing great guns. Now gardening season is back I have put kippers log edging along the front. There’s a decent section at the front of the garden the hedge won’t cover so now I want to plant flowering plants along the front edge.

problem is  I don’t have the reach for the front area I want to plant.

I’ve tried a few things, but I’m having trouble with reach after adding new sprinklers so hoping for some guidance.

what I’ve tried -

1. I added an offshoot of poly with a T for an extra 8 microjets (20 total on dedicated line). Two jets before the last on the line have minimal output, and the second last jet on the original line. When I isolated the new line off the second to last jet on the original line is fine again. I think a 13mm setup may max out around 18 jets? Or by splitting the water flow I’ve reduced the pressure? I’ve replaced the jet heads, wiggled connections, checked for leaks etc. Water comes out in a way that looks like the head is leaking. I haven’t touched the mains water pressure. It’s turned to full so the pressure is whatever is standard for an ACT build. 

2. Giving up on that I removed the second line (so back to one line) and placed the original line to the middle of the garden with 12 x 360 jets. Turns out they don’t reach either the hedge or the flowers. Argh. 

3. Take 3, I tried to feed a new poly under the concrete to run a seperate system for flowers, but the genius who laid the concrete only used a 25mm conduit, not the 40mm I supplied. With new garden beds dug out and sore bruised hands I’ve given up trying to squeeze  a second poly through. Impressive I got it about 1.5m of the 2m through, but even with water shooting through the feed to clear the passage I hit a snag and didn’t want to risk damaging the line that is fed through. Now I have to go back and slowly clear the backfill of water out so the conduit isn’t clogged with mud around the poly inside. Sheesh. 

4. As an fyi I know I could size up to 19mm with an attachment to the 13mm coming out from the concrete but with a mortgage repayment invested in 13mm fittings I’d like to avoid that route. I’m not convinced sizing up would help if the issue is drawing too much water from what the mains are outputting? No other water is being used from the tap, or elsewhere, when I’m running the timer that might impact the output. 

Having exhausted the options I can think of I’ve concluded the single line up the guts is the way to go with 2 rows of 180 jets, one either side of the poly facing opposite directions. Before I lose another day on trial and error I’m hoping for some advice:

1. What is the minimum distance apart I can have sprinklers so each will generate enough water pressure for the 1m reach I was originally getting. Is 500mm between jets enough? Thinking having a jet facing the hedge, 500m along a jet facing flowers and so on. 1m coverage each side, ideally 24 but I think that’s too many?

2. How many jets are recommended as max number on a 13mm system same as the system demo above?

3, When multiple heads are tested on the same sprinkler and solid water stream spills over the top down the back of it with a slight dribble reach out the sides Is this a sign of poor water flow?  

If none of this works I guess I need two lines coming off the main poly feed under the concrete with a tee and isolators to run each line separately. Which is fine, but makes the automated watering function kinda redundant. 
Thanks! I’ve put so much time and research into this as a first time irrigator. I can’t let it beat me!!

[JacobZ]

Hi @Gerdener_Yoshi,

A warm welcome to the Bunnings Workshop community and thank you for your questions.

There's certainly a lot to digest and you've clearly put a lot of thought into it. 

Is it possible to get some photos of your garden as well as the irrigation system that is already in place? This would help me understand what you are dealing with and offer my best advice.

Everything you've said makes it sound like you've maxed out this irrigation line's potential. 18–20 jets seem to be the limit in your circumstance. This is dependant on your mains water pressure and pipe length. Adding a tee does not isolate the lines, so the pressure required will be the same.

Is there any reason you can't use 360° sprinkler heads? They will require slightly more water pressure than 180° heads, but far less than double the number of heads.

The only other option I see being viable is to add a separate irrigation line with a dual tap outlet such as this GARDENA MultiControl Duo Water Computer so each irrigation line can be activated independently of the other.

Allow me to tag @Dave-1, @Noyade and @srobinson to see if they have any thoughts or ideas.

Let me know what you think.

Jacob