Jess Stryker's
Landscape Sprinkler Design Tutorial
Step #5
Congratulations!
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Jess Stryker's |
Well that's it! You're pretty much finished with your irrigation design. Here's a few reminders and additional items.
Automatic controllers: For automatic systems you will need a controller (often called a "timer") with one "station" for each valve. If you have both lawn and shrub areas you should make sure the controller has 2 or more "programs". Multiple programs are somewhat like having several "timers" in the same controller. This allows you the flexibility to run the lawn and shrub irrigation on different days. Study the different models and features available on various controllers. They range from simple timers to extremely complex computerized units that can monitor all the functions of your entire home!
Isolation valves: It's a good idea to install a manual shut-off valve at the point where your irrigation system connects to the water supply. This allows you to shut down the irrigation for repairs. A "gate valve" is commonly used for the shut-off, however I recommend using a "ball valve" as ball valves last much, much longer. Most inexpensive gate valves begin to leak after the first year or so.
Wires for valves: For wires going to the automatic valves use wire made specially to be buried. Most people use a special direct burial cable made for irrigation systems. The cable contains 3, or more, separate, 18 gauge wires. On commercial systems the standard wire used is "#14-1 AWG-UF" which is a single strand, direct burial type wire. One white color "common" wire goes from the controller to every valve, and one individual "lead" wire of a color other than white goes to each valve from the controller. Be sure to read the Irrigation Installation Tutorial. Also there is a sketch of typical irrigation system wiring that should help you understand the wiring.
Details: To further help you there is a collection of installation details. These simple sketches will help you figure out how to assemble your irrigation system. These installation detail drawings are normally included as a part of the design drawings for an irrigation system.
Filters: I almost always install a screen-type water filter on my irrigation systems. Drip systems should always have a filter! This helps reduce maintenance problems caused by small bits of sand which are found in almost all water systems. These small sand grains can clog sprinkler heads over time. I recommend a "150 mesh screen" in the filter. The filter can be installed underground in a box if you don't want it visually cluttering up your landscape. On the other hand, it is nice to have it in a more convenient above-ground location for maintenance. Remember, you need to clean the filter screens at least once a year if not more often! For tons more information on filtration see the Irrigation Water Filtration Tutorial. Click Here
Cold Winter Precautions: In areas where freezing weather occurs you need to take precautions to protect your irrigation system from freezing. There is a whole tutorial just on winterizing your sprinkler system in areas where it really freezes hard. It covers the various methods used, advantages and disadvantages of each, and what you will need to install as part of your new sprinkler system for each method. Click here
Pumps: Thinking you might need an alternative water source for your sprinklers such as from a pond or lake? Check out the Irrigation Pumping Systems Tutorial. Click Here
Unless your irrigation system is in an area where it never freezes you should insulate the backflow preventer and any other above ground equipment. Backflow preventers are very expensive, you don't want an unexpected freeze to catch you off-guard. A few years back that happened here in California and thousands of backflow preventers had to be replaced because the water froze in them and they split open! I usually use foam insulation tape to wrap the backflow preventers and above ground valves, then wrap the insulation with a layer or two of 10mil black plastic tape to protect it. There are also some pretty neat backflow preventer blankets (essentially a big insulated bag), that are made to fit over the backflow preventer like a big coat. They work good, I use them on commercial installations all the time. (I have a small one in my truck that I use to keep cans of soda cool when I'm on the road. It also makes a great pillow!) If the backflow preventer has air vents or a water blow-off outlet it is extremely important that they not be blocked by insulation! There should be instructions that come with your backflow preventer.
How much will it cost?
That's hard to say. I priced out the materials for the little sample irrigation system at the top of this page at $300.00. That included reasonably good quality sprinkler heads, "funny pipe" type risers, Cl 200 PVC pipe, anti-siphon valves, and a very inexpensive $50.00 controller. That comes to about $0.20 per square foot of irrigated area. You may need to add extra for a better backflow preventer and better controller. I would suggest in most cases that you estimate at $0.20 per square foot plus the controller and backflow preventer cost. Installation generally costs about 1.5 times the cost of the materials. The Installation Tutorial will help you assemble a material list for a more accurate estimate.
Installation
Now you'll probably want to move on to the tutorial on installing your sprinkler system! It covers in more detail the various irrigation parts you will use, like sprinkler risers. It also teaches you to "talk sprinklers" (so you can sound like you know more than you do!), helps you make a list of the materials you will need to buy, provides some helpful forms you can print out, explains which tools can make your day or break your back, and a few other tips and tricks! Be sure you read it before you buy anything or start digging!!! (Just when you thought you were finished!)
If you're interested, a user of this tutorial prepared his own installation tutorial after he finished installing his own sprinkler system in Texas. Click here.
Pass it on!
If you found these tutorials useful, how about helping to pass on the knowledge? One of the most common comments I get from tutorial users is that they never expected to find a resource like the tutorials on the web. Another one I hear a lot is "I wish I had seen this before I ..." Well, you can help spread the word and you may just save a friend a bundle of time and money! Perhaps it could be your good deed of the day?
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Jess Stryker's Irrigation Tutorials
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