I’m currently tackling a backyard overhaul project and as part of it, I need to install a few new irrigation zones. I installed this small succulent garden a few years ago which doesn’t require a ton of water. With the heat of the summer, however, I’m still sick of pulling the hose out every time. So today I’m going to show you how I plan to install a sprinkler system for it and some nearby plants.
1.) Water Supply
Step one is to locate a nearby water supply. In this case I have an unused spigot behind my old shed that I plan to tap into to use as the source for this line. To determine how many sprinklers I can have on this line, I’ll have to do some basic calculations. We need to determine our flow rate, and water pressure for the house. The easiest way to test the water pressure is to use a water pressure gauge like this one and attach it to a spigot. In this case, the water pressure is just shy of 60 PSI.
Next, to determine the flow rate I use a 5 gallon bucket and turn the water on fully to see how long it takes to fill the bucket. Multiply the size of the bucket which is 5 x 60 seconds. Then divide that number by the number of seconds it took to fill. In this case, it’s around 20 seconds. So the flow rate is about 15 gallons/minute.
Once you have that number, it can help you determine how many sprinkler heads you can have on a zone or how many zones you need. In this case, I’ll be installing these pop up Rain Bird 1800 series sprinklers and a couple dedicated drip lines. You can check the flow rate of your chosen sprinkler types and what their coverage is on the manufacturer’s website. I only need about 6 sprinklers total for this zone and each head has a flow rate of less than 1 gpm so I have plenty of pressure and flow rate for the needed coverage. Depending on your layout, you’ll likely need to buy a combination of different pieces, fittings, and unions. I recommend you buy more than you need and return the unused stuff.
2.) Digging the Trench
Once all the stupid math is out of the way, it’s time for some good old manual labor! You’ll have to dig a trench to bury the line. Depending on the size of the area you’re working in and the type of soil you have, that can either be easy or a huge pain in the ass. In most cases for irrigation lines, anywhere from 8 to 12” deep is sufficient to bury your pipes; however, if you live in an area that freezes, make sure you plan to drain your lines at the end of the season so they don’t freeze and rupture during the winter.
Once you have the digging out of the way, you can start laying out your piping and sprinkler heads. There are a lot of different products out there you can use. I typically just use schedule 40 PVC pipe because I find it easy to work with. In this case I’m using ¾” diameter schedule 40. I just work my way around, laying the pipe. Whenever I reach an area where I want a sprinkler head I use one of these ¾” tee joints with a ½” threaded outlet where I will screw in a threaded riser for the sprinkler head. At each joint, I use purple PVC primer and cement, making sure to prime each piece and then apply plenty of cement to hold each joint together so they’re water tight.
3.) Connecting the Sprinkler System
Once I’ve laid out and installed all the sprinkler heads, it’s time to connect the line to the water supply. You have a bunch of different options for different types of zone valves here but they all basically do the same thing, they allow the water to kick on either manually when you activate the valve, or on a timer if you have it connected to an irrigation system. Some, like the one I installed here run off solar power and operate on their own.
These “anti-syphon” zone valves allow the water to flow out to the sprinkler lines, but not back-flow and contaminate your drinking water. You install your sprinkler line to the outlet side of the valve and connect the inlet side to your water supply line. Add as many zones as needed based on your flow rate and water pressure. You can even add an isolation valve like this one which allows you to shut off the water to the irrigation lines without shutting off the main water supply to the house.
Once everything is connected, let the cement cure for at least 30 minutes. Then turn on the water and check the pipes for leaks. After that, turn on your zone valve and sit back and watch your plants get watered. Then you can just backfill in your trench and that’s all it takes to install a sprinkler system.
I hope you guys enjoyed this project and I hope you learned something. It can take a little bit of time to install a sprinkler system, but once you get the hang of it, it’s a relatively simple project you can knock out by yourself and hopefully save yourself some money.
If you liked this project, check out some of my other lawn projects:
Thanks for stopping by, and I’ll see you next time!
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