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danreg99 04-11-2011 01:16 PM

DIY sprinkler questions
I have decided to "try" and tackle my sprinkler system for my new home. I went to the rainbird website and downloaded the design grid and questionaire. I filled out the grid with my lot, house and landscaping and filled out the questionaire. The psi of all lines is right about 78 psi (kind of high?) and the gpm is only at 11 gpm. Does this seem odd that my gpm would be that low even with the psi being that high? Has anyone received a design from rainbird and is it worth it? Am I biting off more than I can chew or is doing your own sprinkler system feasable? Thanks for any and all info.


Leah Frances 04-11-2011 01:39 PM

Bump to subscribe.

danreg99 04-12-2011 09:41 AM


DexterII 04-12-2011 04:27 PM

The first thing that I would do is call them, to see if you can talk to a real person, and discuss this with them. As for here, I don't know, but suspect that anyone would need more information, such as length of run, types of sprayers, etc., in order to provide even a rough idea. Also, I'd keep an eye here for a day or so, to see if someone knowledgable in this area comes along, but in the mean time, personally, I would probably be checking my local area for a landscape architect. At least in our area, I have happened onto a lot more of them than I would have ever guessed were out there, but it certainly seems that, considering all of the work that you will put into this, it may be worth spending some upfront money, and get some kind of assurance that you are on the right track. And, by the way, since you plan to do it yourself, I would look for an independent guy or gal, rather than one employed by a landscape firm, so that you know that they are not trying to steer you toward a particular product, or whatever. Just an opinion.

user1007 04-12-2011 05:20 PM

Used to design irrigation systems for a living. Send me a private message if you need specific help and I will see what I can do. Do you have your yard scaled out? That has to be your first assignment.

First thing you need to determine is what you are watering. You are stuck with conventional irrigation for things like lawns and large areas of ground cover but you will be so much happier with a drip system for everything else and it will be better for the plants. Water goes only where you want it. Combined with landscape cloth you will not see a weed in your beds unless an evil neighbor stuck it there.

For typical residential yards, you have no worries with drip with regard to pressure and flow rate since it works in gallons per hour, not per minute and takes near nothing pressure wise. And it is cheap. Most of my residential designs used simple emitters in the 1-4 gph range although they come up to 12gph or more now I guess and in all kinds of configurations.

If you measured and have 11 gpm you have 660 gph? Check my math. That means you could have 660 plants needing 1gph on a single circuit. You will want to divide them up logically and stick them on a timer though. Drip is cheap and a brain dead monkey can install it.

Now then for the lawns. Each sprinkler head has a flow rate rating and a pressure rating as well so to answer your question you need to substract both as you loose both as water moves down the line (same with drip but it is not so critical) and shrink the line size as you get toward the end of the line to keep the pressure up. Your challenge is to keep as much pressure and water flow in the line so that all the heads work at peak performance. For a small residential installation this is usually just a matter of splitting things into different watering circuits. No rule says you have to water the whole lawn at one time right?

The other trick is determining the pattern for the head for a lawn. Sprinkler companies issue wonderful claims for what a sprinkler head should cover and in the real details reality. Two patterns are used to determine what you need. A square layout and a triangular one.

Use the latter and draw a series of equilateral triangles on a piece of tracing paper large enough to cover the scale drawing of your yard. Each side of the triangle should match the realistic data for the radius of water each sprinkler should spray as best you can determine from the sprinkler data. Use a compass to draw the circles from each point. What you will see is a nice overlap with no bare spots?

Now move this grid around in all directions on your scaled drawing with the ideas that each point of the triangle will be a sprinkler head location. You don't want one hanging from a tree or in the middle of a sidewalk right?

Once you have the heads located without watering the street, house and so forth you can begin to select the head patterns. 1/4, 1/2, 1/3, 3/4 circlce and so forth. Many rainbirds have those springs where you can adjust the pattern. I used to love Toro heads best of all and they came with templates that you could even customize.

Now then your water pressure is not terrible I guess but are you hearing some hammering when water is turned on and off? Wait until you automate your sprinkler valves to come on early in the morning, the optimum time to water. You could save yourself a blown water main line, with or without sprinklers by reducing that a bit as near as the water company main as they will allow.

As for valves for your sprinkler system. You need to make sure they have anti-syphon or backflow prevention somewhere. You are not going to need that many. They can be built as a manifold or remote but consider you will have to run wire. A ulti-station timer is going to cost like $30 for a residential yard these days.

Does this help you make more sense of it all? And of course you can do it yourself but think about a plumber for house connections if that is not your skill set.

CALL YOUR EQUIVALENT OF JULI, the utility location service here in Illinois that comes out and marks everything for free. Hit a line of any kind with a trencher and it is going to cost you big time.

danreg99 04-13-2011 03:37 PM

Thanks SDsester, lots of good info. I have scaled out yard on graph paper (this is what I sent to rain bird). Should I wait to install sprinklers after the landscaping is done (so I know where to install drip lines?). Would you mind looking at my layout? If so, what is your email address? Thanks again for the info.


user1007 04-13-2011 08:31 PM


Originally Posted by danreg99 (Post 628770)
Thanks SDsester, lots of good info. I have scaled out yard on graph paper (this is what I sent to rain bird). Should I wait to install sprinklers after the landscaping is done (so I know where to install drip lines?). Would you mind looking at my layout? If so, what is your email address? Thanks again for the info.


Not comfortable posting my email for all to see so send me a private message and we will go from there.

You will want to trench and install all your water supply lines (again after calling your utility locating service) and your lawn/ground cover sprinklers etc. as part of your overall landscaping plan and certainly before you seed, hydroseed or lay sod. Drip is based on flexible 1/2" tubing that lays on the surface, at least where you have emitters, so it can and should go in after your major plantings are placed. It is best to put it down first for areas where you are going to put bedding plants and so forth though or you could damage them. You will punch the tubing and install the emitters after you have laid out the tubing. You want to lay the coil in the sun awhile to warm it up and release some of its "spring" and you may need some yard staples to hold it initially.

danreg99 04-14-2011 03:29 PM

message sent

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