I did one for my lot of a little over 2 acres. It is s imple setup using a 6 zone indexing valve (1.5") and thinwall pipe. Basically do a layout figuring out how many gallons per minute you need and work it backwards to the pump / well. Smallest pipe I used is 3/4". Funny pipe (black flexible pipe) and elbow connections to rotor heads allow the heads to be moved when run over without breaking the pipes. The outlet in the supply pipe is on the side, and then an elbow connection (threaded to allow rotation) connected to a small (16-24") funny pipe section (1/2") connected to another elbow connector connected to the bottom inlet of the rotor head. If you buy the Krain series they come with a variety of nozzles to adjust the flow rate. If the zone uses all full circle heads, just use the highest flow nozzle your pump / well will support. We got about 100 gpm out of the well, so if a zone has 12 heads all full circle then I can go as high as an 8 gpm nozzle on each head. If you have some half circles then you should use a lower flow nozzle on those since they will be covering the spray area twice as often, thus giving you the same net watering as the full circles as the higher GPM. Ideally you should space the heads so that you have full overlap (one head can spray to reach the next one), but that did not work for me, so I went with a spacing of 1.5 spray distance. The rotors generally go about a 40' radius spray, so I have mine at around 60' on center. The design pros recommend you keep the water flowing at a maximum of 5 feet per minute, so a 100 gpm flow from the index valve would require 3 inch pipe. I went with 1.5" for economy, but it will only last maybe 20 years or so (the higher flow rate eventually tears up the connections). We have been here 10 years and not had much of a problem. You can avoid pipe breaks better with schedule 40 pipe, or running larger funny pipe for the mains, but that costs more, and schedule 40 has a much smaller inner diameter meaning less water can flow through it easily. If you trench and bury at 12" you should nothave any problems, I used the rotary trencher that supposedly did a 2" trench 8" deep, but I had trouble getting a 1.5" pipe more than 4 inches below the surface. I'd recommend using a ditch witch for the trenching and make sure you call the utility marking service prior to the dig. We don't want to read that you got fried hitting an underground powerline!!! BT Edit: Also flush out the lines before you install the heads (leave the funny pipe sticking out of the ground to run the pump and get rid of little debris that could clog the heads). It is an exhausting project, but it saved me about $4000 compared to having a local irrigation company do the job. We used about 8,000 feet of pipe altogether. Also, get you main piping from an irrigation company. They sell 20 foot lengths of pipe with a belled end to make the long runs easy (just a pipe to pipe connection every 20 feet). If you go to Home Depot you will be making 2 connections every 10 feet (pipe to couple, coupler to next pipe).
^^^ Wow, thanks for the thoughtful reply. So, I suppose you rent the trencher for a day or two? Did you use RainBird or another brand for the controller and spray parts? Good tip on the line flush. Things like that dson't become apparent until you've done it once!
I have installed 5 and next spring I will be installing my 6th. All have been trenched except for one where a friend who is in the irrigation business pulled the pipe and then I installed the sprinkler heads, valve boxes, etc. I prefer the impact heads with Rainbird. I used Orbit spray heads one time and I just like the sound of the impact. If you use impact heads you will have to run your system longer to get the same GPH (gallons per hour) as the spray heads. It is not that hard as long as you are not afraid of messing up, which will happen somewhere in the process. The most difficult part for me has always been tapping into the main water line and installing the backflow preventer since that line is usually pretty deep. PM me if you have any specific questions. Good Luck, Reese
Great info Bill and timely post Uro, thanks. A few years ago, I helped my neighbor install his. Basically, he took a diagram of his property to Lowes and they designed a system for free (three zone manifold with timer). He then knew exactly what materials he needed, and for where (multiple diameter piping with reducers to maintain equal head pressure). He also had a well drilled and added a separate water meter (city charged sewage for every drop of water used). Fortunately, he had a small yard so it didn't take too long. My current yard is about 5 times bigger and am getting ready to tackle this project as well.
<brakes squealing, smoke boiling out> Wait. You have to tap into the main water line? That's pretty scary.
In the past I've hired a plumber to tap into the line for me and then done the rest myself. Plumbing and electrical are about the only two things I won't do myself at my house.
I have only done the system using a drilled well with two wellpoints about 40-ish feet deep. A well driller testes the outflow using a 5 gallon bucket attached to a 2 hp gas water pump to see if it fills in less than 5 seconds for a 60 gpm flow, 3 seconds is a 100 gpm flow. As an indication after I installed the system one head failed at the end of the zone, and the remaining 9 heads were all putting out around 6 gpm each, with a total run of about 500 feet to the broken head. The broken head was still receiving full pressure and geysering about 40 feet into the air. I tried to screw the head back on for about 20 minutes but could not overcome the pressure in the pipe. Regarding the posts above about tapping into the main line, I'd hate to pay the water bills for watering an entire lawn with city water. We typically use about 20,000 gallons per night when the system is on. The trencher is a rented piece of equipment, and I recommend the ditch witch variety. They look like a giant chain saw on two wheels with a hydraulic control for the angle that the trencher is digging at to vary the depth. The drive system can be disengaged to a single wheel, and I forgot to switch back to the two wheel drive when trenching for my city (house) water, so I was fighting the machine's tendancy to turn the entire time I used it. I also prefer the use of the blue PVC cement as it seems to be a little more workable when you put the joints together compared to the clear stuff in the gold can. BT
To be more specific, the main water supply line that is in your yard after the water meter for your property only. The first system I tapped into the water line once it was inside my house in the basement. No digging required! The problem was that every time the system came on I heard it on the first floor. If you tap into the water supply line outside of your house you will not hear the system running.
You may want to chat with your water provider about setting up a second meter/supply for the irrigation system. As others mentioned, you get charged for sewer on your main line even if it never hits the system (pool, irrigation, etc). Many providers can set up a modified billing for the second meter. When you put it in, make sure you have flex hose to the heads themselves from the lines. Solid line to a head WILL get shattered at some point when someone runs over a head.
Sorry I forgot to answer your question about the timer, etc... I use K-Rain Pro heads and sprayers, generic funny pipe and PVC, and a regular industrial timer like whast you would have for pool equipment. It is actually in the subpanel for our pool pump which has two timers (one for the pool pump, one for the sprinkler pump). We use the big chunky brass timer on and off indicators so the shortest time we can make a zone work for is about 45 minutes or so. It really doesn't matter which brand you use, Toro, Rainbird, K-pro are all pretty good. Our store stocks Toro for the funny pipe connectors, but they are press in type, while the irrigation supply store uses another brand that the threads actually cut into the funny pipe, and it screws or pushes in, and screws out. The Toro ones are very difficult to take out, so I usually just cut them out if they need to be replaced for any reason. If you are using city water you can still use an indexing valve, but if the lot is less than 1/3 acres I would just have a manifold with a low voltage controller and electric valves as the indexing valve is an unneccessary complication on such a system. Another thing: If you are getting a well, try to put it someplace close to the panel if it is not unsightly, and build a small enclosure so the lawnmower does not damage it with an accidental impact. Of course you are going to be the yard guy, but it will be one less thing to mow around if it is tucked nicely near the house or a natural area... BT
