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How To Install an Underground Sprinkler System on a Budget

A sprinkler system adds significant value to a residential property and can save a yard-care person time and money. However, a professionally installed system normally costs from $1500 to $2500 for a 2500 ft2 front lawn. An average or $2000 system usually breaks down as follows:

  • plumbing connection $500
  • electronic controller $300
  • piping and heads $500
  • labor $700

Adding a 2500 ft2 back yard tacks on another $1000.1 I was able to install a basic but effective system on my own for just over $500.2 A year later it still runs smoothly and I continue to realize the benefits of my labor. The secret? I use the unique method of installation3 detailed herein featuring flexible PVC, long-range rotors, in-line timers and filtered drains. This article details that installation process, but it is assumed that the installer has taken all necessary preliminary action (e.g., investigating if a sprinkler system would be advantageous and effective in the desired location,4 any and all legally required action,5 etc.).

Planning

While planning is the most time consuming part of putting in a sprinkler system, doing it well can save you significant work and ensure effective watering. The following planning steps are intentionally brief as detailed planning6 is outside the scope of this article. The fundamentals, however, are all present.

Plot Your Lot

Start planning your sprinkler system well in advance of the planned installation date as this will keep you from sacrificing quality to meet a deadline. Begin by obtaining a lot survey which should be among the appraisal information you received when you bought your home. If you are unable to obtain a survey of the lot you will have to measure its dimensions manually. Plot the gathered information using a graphing computer program (the most effective and exact method) or a pencil and a sheet of graph paper. If you go the paper route, be sure to sketch the lot large enough; a smaller plot is less exact and harder to work with. Once the general geometry of the yard, home, driveway, sidewalks, fences and other important features are plotted, mark the locations of all available water spigots.

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Figure 1. Example of Lot Survey of Residential Home

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Figure 2. Lot from Figure 1 Plotted in Autodesk Inventor

Additional Preliminary Information

Depending on the extent of your planning process, you may need to gather the following information before continuing.

  • Water pressure – Determine your water pressure either manually through the use of a pressure gauge or by calling your local municipality. If using the pressure gauge, turn off all other water faucets (both inside and out) and attach the pressure gauge to an outside faucet. Turn the water on at the appropriate spigot and record the pressure reading7 on the gauge.
  • Water meter size – Determine your water meter size from either the meter itself, a utility bill, or your water provider. Water meters are typically 5/8", 3/4", or 1".
  • Service line size – Determine your water service line size by wrapping a piece of string around your water service pipe once and then measuring the length. Compare the result to Table 1.
  • Flow rate – Determine your water flow rate by timing how long it takes to fill a container to a measurable level. Divide the filled volume by the measured time and convert to gallons per minute or gallons per hour.8
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Figure 3. Typical Pressure Gauge – EZ Flow $7.96 @ Home Depot

Table 1. String Length to Pipe Size Conversion Table

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Choosing Heads

The sprinkler heads you choose determine the rest of your design and they are a key component to this unique installation. Opposed to most residential systems that include many stationary, small sprinkler heads in a grid covering the lawn, this method involves using fewer, larger, rotor-style heads which will require less installation materials and labor. The most popular sprinkler system brands are Rain Bird and Orbit, both of which offer rotor-style heads to meet this need. Styles with adjustable ranges are particularly convenient, as a home’s individual water pressure and flow rate will cause head performance to vary greatly. In this installation, I use the Rain Bird 32SA Full and Part Circle Gear-driven Rotor.

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Figure 4. Rain Bird 32SA Full and Part Circle Gear-Driven Rotor – $9.99 @ Home Depot

Planning Zones

Once you have selected sprinkler heads, toy with various arrangements on your yard plot. Irrigation system design sites all encourage head to head coverage,9 but I recommend starting with single coverage and then expanding later as required. Look to minimize the number of heads necessary by adjusting placement. You may even choose, as I do, to neglect certain areas of the yard that either need less water (e.g., areas watered by drainage or the neighbor’s sprinklers, shaded areas, less needy plant/grass types, etc.) or that you are willing to let die. The two neglected areas in my yard plot are the thin strip of grass along the right side of the house (shaded and gets runoff from both my and my neighbor’s backyards) and the thick segment on the left-front (neglected due to location).

Try to avoid placing heads between the sidewalk and the street (if applicable) as they are harder to install. Place as many heads as possible close to fences or walls as heads in low-traffic areas are less likely to get damaged. I forego this last piece of advice in my initial plan, as evident by the heads in the backyard noticeably located away from fences and walls, with the intention of keeping the number of heads to a minimum (see Adding and Adjusting the System).

After deciding on a head placement, divide the heads into zones. Your water pressure, flow rate, and head size will determine how many heads you can put on one zone. My final design included six sprinkler heads so I assigned two to each spigot. Plot lines from each spigot to the heads for which they will provide water. Straight lines are not necessary (more on that later) but, again, avoid running lines under sidewalks or driveways if possible. After the head locations are secured, it may help to measure distances on the plot from landmarks (e.g., fences, sidewalks, walls, etc.) to facilitate locating the corresponding spot in the yard.

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Figure 5. Yard Plot with Head Placement

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Figure 6. Yard Plot with Heads, Spigots and Pipelines

Purchasing Materials

After a nice and thorough planning stage, let the buying begin. Although the shopping list will vary, the following guidelines may prove helpful, as well as provide a preview to the system and how it will work. I suggest purchasing materials for only one zone initially and installing it as a test zone. This will also spread out your expenses and work load, as well as allow you to adjust your planning for other zones if necessary.

Splitters and Timers

To avoid having to pipe to a manifold and buy an expensive timing system, I use one relatively inexpensive in-line timer for each zone. These timers hook up directly to the spigot, are battery powered and weather-proof. I also purchase a splitter for each spigot to allow access to direct water without having to disconnect the sprinklers. Note, however, that neither a splitter nor timer is necessary for a functional sprinkler system; you may choose to postpone the purchase of one of both in order to spread out the cost. Integrating them at a later date is next to effortless.

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Figure 7. Mister Landscaper Electronic Water Timer w/ Easy Dial – $29.98 @ Lowe’s

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Figure 8. Garden Plus Brass Y Connector – $5.96 @ Lowe’s

Heads

Purchase the number of heads indicated by your planning, whether for your test zone or all zones. Be sure to save the head receipts, however, as heads are returned frequently. Not only are they the most defect and damage prone, they are often poorly chosen. With a receipt, damaged, defective or poorly chosen heads can be returned and replacements bought after any necessary planning adjustments.

Pipe

The type of piping used is another key attribute of this installation method. Instead of the typical rigid PVC, I use 3/4" flex PVC. Flex PVC is more expensive and harder to find than rigid PVC, but it more than makes up for the purchase cost and inconvenience through the following advantages:

  • Connection Frequency Reduction – Flexible PVC is easily bent and maneuvered and does not require connections at corners, angles, or changes in depth.
  • Plan Flexibility – Because flex PVC can adapt to most any line configuration (other than very sharp turns that will kink it), you can change line direction easily, even in the middle of installation, without having to hassle with re-thinking the entire line design or purchasing additional connections.
  • Backflow Prevention – The line flexibility allows a simple and inexpensive solution to prevent backflow through the line. (See Installation: Connection to the Spigot and Figure 24)
  • Adaptability – The spigot hookup method allows things like fertilizer to be easily added to the yard through the sprinkler system.
  • Cutting – Flex PVC can be cut and prepped easily with a utility knife whereas normal PVC requires additional tools and effort.
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Figure 9. Water Whiz Irrigation 3/4″ × 50′ Flex PVC Pipe – $28 @ Lowe’s

Fittings

Normal, rigid PVC fittings can be used to make flex PVC connections. These are very inexpensive, so I suggest buying some spares to avoid an extra trip to the hardware store. Outside of basic unions (Figure 10) and tees (Figure 11), this sprinkler system installation will require some slightly specialized fittings:

  • Soc 3/4" x Soc 3/4" x 1/2" female NPT10 – This connection will go at the base of each sprinkler head. It is just like a 3/4" tee, but the intersecting opening is prepared for a 1/2" male NPT fitting. See Figure 12.
  • 1/2" x 6" Riser11 – One of these is needed to connect the bottom of each sprinkler head to the tee below. 1/2" represents the size of the connection (1/2" male NPT) and 6" represents the length. Various lengths are available with segments that can be cut off to provide the proper head height. See Figure 13.
  • Spigot to 3/4" Soc – One of these will be needed at each spigot. See Figure 14.
  • 3/4" Soc to 1/2" female NPT – Most drains and plugs have a 1/2" male NPT thread. Thus, for each drain installed, an adapter will be needed going from 3/4" PVC to 1/2" NPT. See Figure 15.
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Figure 10. 3/4" Soc x 3/4" Soc Coupling – $0.14 @ Lowe’s

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Figure 11. 3/4" Soc x 3/4" Soc x 3/4" Soc Tee – ~$0.25 @ Lowe’s

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Figure 12. 3/4" Soc x 3/4" Soc x 1/2" female NPT Tee Connection – $0.34 @ Lowe’s

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Figure 13. 1/2″ × 6″ Riser – $0.28 @ Lowe’s

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Figure 14. 3/4" Soc x Spigot – $1.29 @ Lowe’s

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Figure 15. 3/4" Soc x 1/2" female NPT Bushing – $0.31 @ Lowe’s

Drains

The final key aspect of this installation method is the use of filtered drain valves. Filtered drains hold pressure during watering and allow water to seep out of the piping between uses. Without the potential for residual water in the lines over winter, you can bury the piping above the freeze line which greatly reduces the labor and machinery needed. Purchase at least one drain for each line to be installed at the lowest spot in the circuit. If there are multiple low spots, use more than one drain.

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Figure 16. Rain Bird Filtered Drain Valve – $2.98 @ Lowe’s

Tools and Other Materials

You will also need to gather the following to perform the installation:

  • Shovel – A spade style shovel with a handle works best.
  • Glue – Standard PVC cement will be used for the connections. Primer is not necessary and a 4oz can will suffice for most yards.
  • Knife – You will need a box-cutter or utility knife to cut the flex PVC.
  • Teflon Tape – You will need a roll of 1/2" Teflon tape for threaded connections (except where noted).
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Figure 17. Teflon Tape .5″ × 260″ ($1.98 @ Lowe’s), PVC Cement ($3.35 @ Home Depot), Utility Knife ($3.96 @ Lowe’s), and Utility Knife Blades ($0.98 @ Lowe’s)

Installation

Once you gather all of the necessary materials, the installation fun can begin. The following instructions will detail the main installation steps. While it is important to start with Preparation and end with Covering the Lines, some of the steps can be interchanged.

Preparation

Before grabbing the shovel and going nuts on the yard, you may want to either wait for some rain or water the area with your soon-to-be-obsolete manual sprinkler. Depending on the hardness of the ground, a little water could make the digging much easier. Also, string your flex PVC out on the driveway or porch so it can get some sun. This will soften the pipe and make it easier to cut and bend.

Digging

Instead of digging trenches you will be ‘slotting.’ To create slots, insert a spade-style shovel about six inches into the ground and pull back. Then flip the shovel and do the same thing in the opposite direction. Repeat this process all along the path of the future underground line. It may be helpful to test the size and depth of the slot by jamming a segment of flex PVC into it after a few feet have been slotted (there is no need to cut the PVC to accomplish this). Adjust your digging style per your findings.

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Figure 18. Slotting

Running Lines

Getting the lines into the slots is easy enough once you have slotted the way, but some planning is necessary before starting. Start at the spigot end of the slot and leave enough PVC to run up to the spigot, plus an additional three feet (which will be explained later). Then insert the flex PVC into the slot by jamming it in place with the handle of shovel or the head of a medium sledge hammer. At the other end of the line and at any sprinkler head location, cut the line leaving an extra three to six inches. Repeat the process for other lines to be installed, keeping in mind that it’s much easier to cut a few extra inches off than to add a connection to lengthen the line by the same distance. After putting the lines in the slots, all that remains is to bury them by pushing the sides of the slot back together. I recommend you postpone this step, however, until after the system has been tested to avoid having to dig up and re-bury lines if any adjustments are necessary.

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Figure 19. Inserting PVC into Slot

Making Connections / Installing Tees

You will have to make multiple connections on each line. Follow the same procedure whether you are inserting a tee to split the line on the way to two different destinations, installing an in-line sprinkler head, or ending the line to add a plug or drain. See Video 1 for a video of making a connection.

  • Cut the PVC – Use the utility knife. Avoid cutting at an angle; a flat surface will allow for the best connection.
  • Clean and Dry – Make sure all pieces to be connected are dry and free of debris.
  • Test the Connection – Test-join the pieces (prior to applying cement).
  • Apply Cement – Swab around the outside of the male end and the inside of the female end.
  • Make the Connection – Insert the male end into the female end and make a half turn to spread the glue evenly.12
  • Drying – Allow sufficient drying time before applying pressure.13
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Video 1. Example of Making a Connection (Note: Video is currently not working.)

Installing Sprinkler Heads

Most heads come with detailed installation instructions. Read these thoroughly, including information on adjusting the coverage of the head after its installation.

Follow the same installation process at each sprinkler head location. Start by wrapping Teflon tape around the 1/2" male NPT end of the riser prior to screwing it firmly into a 3/4" x 1/2" female NPT tee. If the riser has multiple segments, you can now cut it to fit whatever depth you wish to bury your line. I recommend cutting off all but one full threaded segment using the utility knife. This will save you some digging trouble by allowing you to bury the line as shallow as possible. Next firmly screw the sprinkler head onto the riser and then back it off one full turn. This combination of the tee, riser and sprinkler head will be referred to as the head assembly.

Next, make an extra-wide and deep slot at the future sprinkler head location to accommodate the sprinkler head assembly. Just how ‘extra’ will depend on the size of your sprinkler heads and how deeply you are burying your line. The slot is sufficient when it is deep enough to keep the top of the head assembly at dirt level and wide enough to allow the sprinkler head to be turned by hand.

Once the slot is done, place the head assembly in the slot and position it as if it were installed (with the through tee turned to be in-line with the PVC). Run the PVC through the slot up to the head assembly to approximate where to cut. Cut the PVC and connect it to the head assembly per the instructions in the ‘Making a Connection’ section, making sure to test the head position when testing the connection without cement.

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Figure 20. Head Assembly – Head, Riser and Tee

Terminating Lines

Most lines terminate at a sprinkler head location.14 However, instead of plugging the end of the head assembly base tee, install a six to twelve inch segment of PVC and then a 3/4" Soc to 1/2" female NPT fitting. Then, wrap a layer of Teflon tape around the threads of a plug or drain and screw it firmly into the fitting. The extra segment of PVC will allow you to connect in future lines or replace/move the drain without having to disassemble the head assembly.

Connecting to the Spigot

At the spigot end of the line, install a splitter, timer and 3/4" Soc x Spigot fitting. Close all valves on the splitter and spigot, apply a layer of Teflon tape to the spigot threads, and tightly screw on the splitter. Turn on the spigot faucet to check the integrity of the connection. If there are no leaks, then apply a later of Teflon tape to the timer threads and tightly screw on the timer.15 Ensure the dial on the timer is in the "OFF" position and then open the splitter valve on the branch leading to the timer to check the integrity of that seal.

Before connecting the line to the timer, configure a make-shift backflow-preventor by burying a loop made of the extra PVC mentioned previously. Make the loop as small as possible to avoid extra digging, but be sure not to kink it as this will restrict water flow. This loop will provide a high spot in the line which will prevent backflow of dirty yard water into the house’s drinking water supply. Alternatively, a backflow prevention device or vacuum breaker16 can be purchased and attached to the line.

With the loop and timer in their desired final position, cut the PVC to length against the spigot. Although the timer and splitter will most likely account for some of this distance, leave enough length to connect to the spigot directly.17 Glue the PVC into the 3/4" Soc x Spigot fitting and, when dry, connect to the timer threads using Teflon tape.

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Figure 21. Spigot, Splitter and Timer

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Figure 22. Backflow Prevention Loop

Testing the System

Once you have slotted, run the lines, installed the head assemblies and terminated the lines, it is time for a system test. This can be done before any of the lines or heads are buried to allow you to make any needed changes. Turn the timer dial to "ON" and inspect the performance and integrity of the system. The heads will most likely not be shooting the proper distance or direction as you have not yet adjusted them and they do not have the support of the ground around them. The important thing to check for first, however, is if the system is holding pressure and if the pressure is sufficient to function all of the heads. If the water does not pop up the sprinkler head rotors or if the water shoots a very short distance, you either have a leak or you over-estimated your water pressure. In many cases, the water pressure is more than sufficient, shooting the water into the neighbor’s yard or over fences. This is the optimal case; you can adjust the range of the heads and there is enough pressure to push additional heads if an expansion is added in the future. Check all connections for leaks and turn the timer dial to “OFF.:”

Adjusting the Heads

Most turning sprinkler heads have a fixed left-stop that you must align with the left end of the coverage area. To find the left stop, rotate the head rotor with the palm of your hand all the way to the left, then all the way to the right, and then all the way back to the left. The ending position is the fixed left-stop.

After the left-stop is located, tighten the head onto the riser (without turning the rotor) until the left-stop is aligned with the left end of the coverage area. This tightening is possible because the head was backed off in Installing Sprinkler Heads. While tightening, pay attention to the difficulty of turning the head; tighten it enough to make a seal but not so far that the threads on the head or riser are compromised. When all of the heads on the system are aligned, turn the water on to observe the left-stop alignment. After making any necessary adjustments and burying the heads as described in Covering the Lines, you can make the remaining head adjustments: right-stop alignment and radius. Figure 23 shows the adjustment system of the Rainbird 32A head: a larger slotted screw (top) to adjust the turning angle and a smaller slotted screw (bottom) to adjust the coverage radius.

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Figure 23. Top of Rain Bird 32SA Rotor Sprinkler Head – Adjustment System

Covering the Lines

Close the slots over the top of the PVC lines by stomping on their sides. If you are a light-weight, you can use the handle of a shovel or the top of a sledgehammer. Watering the ground may also help. Before closing in the slot around the heads, be sure the top of the head sits low enough so as to be inconspicuous and avoid the lawnmower, but high enough not to become covered or overgrown. When it is at the correct depth, be sure to pack the sprinkler heads in firmly, avoiding head tilt as much as possible.

How Much and When to Water

Once your system is installed it is time to set the watering cycle. How long and how often to water depends on your grass type, soil type, weather and the rotation of your heads. A good rule of thumb to follow is one inch of water per week.18 An easy way to gauge how much your system waters is to measure how long it takes to fill a tuna can, being careful to note that coverage may vary from location to location. Alternatively, place four tuna cans in different locations and water for 15 minutes. Then, combine the contents of the cans into one can and measure the height. This is your approximate watering rate per hour. Also, it is usually best to water in the early morning hours. Water pressure is usually highest at this time and you can minimize the water lost to evaporation. The early morning is preferred over late at night to prevent fungus growth.19

Adding to and Adjusting the System

After observing your system’s performance and the subsequent grass growth, you may wish to expand or modify your system by adding or moving a head. An addition is easily accomplished by carefully digging up the nearest line, cutting it, adding a fitting and then plumbing the new head to it. Figure 24 shows a number of modifications I make to my system: an added line and head for more water in the front yard (purple),20 and a moved head to provide additional coverage next to the fence in the side yard (red). You can make as many modifications and additions as you want, as long as the water pressure is sufficient to run all the installed heads to the desired coverage.

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Figure 24. Added Sprinkler Lines and Coverage

System Care

Once the system is installed it requires very little maintenance. However, you should be aware of the following guidelines:

  • Short-Term Disabling – Avoid over-watering at times of precipitation by following the timer’s instructions for temporary disability. If you are using the timer pictured in Figure 7 and Figure 21, this is accomplished by simply turning the dial to "OFF." When watering is again needed, turn the dial back to the previous watering duration and the timer will revert back to the previous watering cycle. Alternatively, the timer can be left alone and the faucet turned off. The valve in the timer will still open and close, but no watering will occur.
  • Long-Term Disabling – During winter, timers and splitters may be removed if desired.
  • Adjustments – Adjust watering cycles according to the weather. Heat, drought and rain may all warrant watering changes.

The Finished Product

When completely finished, take time to enjoy watching your system in action. Also, consider giving your old manual sprinkler a proper goodbye with a sledgehammer or a 100 ft drop, whichever brings you more satisfaction. Alternatively, you may choose to wire it to the grill of your car or truck as an everpresent reminder, or simply to enjoy a good chuckle while pawning it off on some poor, sprinkler-moving sap. In fact, you may find yourself enjoying such humor often – anytime you see a a professional installer backing a trench digger off of a trailer, observe a neighbor’s watering ritual every half-hour, or happen upon an overturned traveling tractor-sprinkler pathetically digging itself a muddy grave. Chuckle on, my friend; you have conquered.

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Figure 25. The System In Action


Notes

1 Foster, Ruth S. “Choosing a Sprinkler System for Your Lawn.” BobVila.com. Accessed July 2005 from http://www.bobvila.com/ArticleLibrary/Task/Landscaping/SprinklerSystems.html.

2 Examples of very detailed but unnecessarily complicated installation guides: Barnhart, Roy. “How to Install an Underground Sprinkler System.” DoItYourself.com. Accessed July 2005 from http://doityourself.com/lawn/installundergroundsprinkler.htm. Stryker, Jess. “Landscape Sprinkler and Drip Irrigation Installation Tutorial.” IrrigationTutorials.com. Accessed July 2005 from http://www.irrigationtutorials.com/install.htm.

3 The method of sprinkler system installation described herein was developed and taught to the author by Eric Larson.

4 According to “Installing an Underground Sprinkler System” on Lowes.com(Accessed July 2005 from http://www.lowes.com/lowes/lkn?action=howTo&p=LawnGarden/UndergroundSprinkler.html&rn=RightNavFiles/rightNavHowTo): "Some areas do not adapt well to portable hose end sprinklers. Under some conditions, a high arcing spray emitted from a sprinkler may blow away or partially evaporate before it hits the ground. The type of grass in your lawn also determines irrigation needs. Some turfgrass varieties have higher water requirements than others."

5 Required legal action may include doing the following: Determine if your locality requires a building permit. Check for underground utilities before digging by calling the North America One Call Referral Service at 1-888-258-0808. Research your local municipal watering ordinances. Check your local building codes to identify any potential issues.

6 Some useful sites for further information on planning: “Installing an Underground Sprinkler System.” Lowes.com. Accessed July 2005 from http://www.lowes.com/lowes/lkn?action=howTo&p=LawnGarden/UndergroundSprinkler.html&rn=RightN&avFiles/rightNavHowTo. “Sprinkler Design Service.” Rainbird.com. Accessed July 2005 from http://www.rainbird.com/diy/design/. “System Design Service and Guides.” Toro.com. Accessed July 2005 from http://www.toro.com/sprinklers/guides.html.

7 Pressure gauges typically provide pressure readings in units of pounds per square inch (psi).

8 For unit conversion help: “WWW Unit Converter.” DigitalDutch.com. Accesed July 2005 from http://www.digitaldutch.com/unitconverter/.

9 Head to head coverage is defined as the end of one sprinkler range landing at the adjacent sprinkler heads.

10 NPT is an abbreviation for National Pipe Thread. National Pipe Threads are standard in the U.S. for tapered threads and are commonly used to join plumbing fittings.

11 A 3/4" Soc x 3/4" Soc x 3/4" female NPT tee may also be used. In this case, the riser should be configured to have a 3/4" NPT on bottom and 1/2" NPT segments on top.

12 Reference the instructions on the outside of the cement container to supplement the instructions included here.

13 Reference the details on the cement containter label for approximate drying times as well as other precautions/procedures to follow.

14 You may wish to run extra PVC from the last sprinkler head on the line if you plan on expanding the system later and want to install the PVC now.

15 If a timer is not to be installed at this time, simply skip this step and treat the splitter end as the timer end when following the rest of the installation instructions. If neither a splitter nor a timer is to be used, treat the spigot itself as the timer connection.

16 For more information on backflow and backflow prevention: “The Johnson Corporation: Vacuum Breakers.” Joco.com. Accessed July 2005 from http://www.joco.com/products/vacuumbreakers.html. “Backflow Prevention.” Eweb.org_. Accessed July 2005 from [http://www.eweb.org/home/water_quality/backflow.htmquality/backflow.htm].

17 This extra length will allow the line to be hooked up to the spigot directly in case of the removal of the splitter and/or timer. It will also give some room to insert attachments into the line, if desired, for things like fertilizer.

18 For more info on how much to water your lawn: “How Much Should I Water?” AllAboutLawns.com. Accessed July 2005 from http://www.allaboutlawns.com/lawn-maintenance-care/how-much-should-i-water.php.

19 For more watering tips: “Keeping Your Lawn Well Lubricated.” American-Lawns.com. Accessed July 2005 from http://www.american-lawns.com/lawns/watering.html.

20 While the area covered by the added sprinkler head appears from the diagram to already be receiving water, the need for more coverage here was apparant in the grass growth and color.

21 Yard diagrams were contructed using this software: “Autodesk Inventor.” Autodesk.com. Accessed July 2005 from http://usa.autodesk.com/adsk/servlet/index?siteID=123112&id=4291253.

Information This article was edited after publication by the author on 06 May 2009. View changes.
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Brandon, nice article. The pics make it all quite clear. I just hope you’ve washed your hands since figure 4. :-)

I was wondering if you’d noticed any major cost differences for water with and without the system installed. In other words, were you paying more or less for water when you were watering your lawn manually. I would assume you paid more then as you most likely watered your lawn in daylight.

Just curious if there was a significant difference or not.

Good article Brandon, your yard looks great. I’ve really enjoyed my system, the yard stays green and it only took a few hours to install and saved considerable $$.

After reading, I had a couple of comments on some things I did on my system (just like yours!):

  • The flow rate from each spigot is important to ensure that your sprinkler heads are spraying as far as you need. If you add multiple heads on a single spigot line, the flowrate will drop. One of the reasons to use the 30 ft throw rotors is to avoid multiple heads. If you start with a low flow and add heads, the coverage may not be what you expected. The websites for the spray heads have a distance vs. flow type of chart to help out. You can also add ‘zones’ and run different sprinklers at different times to keep the flow rate up.
  • I think most building codes require some sort of backflow device. You noted to use the loop in the line or a commercial version. The loop has to be large enough to be above any other point in the system. Many spigots now have backflow devices also.
  • I like the comment about putting the heads in semi-protected areas. I broke one this past weekend.
  • I added pea gravel at the discharge filters to try to prevent dirt from packing up on it (although I’m sure it does anyway).
  • You probably want to record the line routing on the lot plan in case you ever want to dig a hole or add something. It’s easy to forget where your line is after a couple of years.
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Are you kidding? by Anonymous

Your claim that you saved a lot of money over a professional installation without sacrificing watering quality is preposterous!

I challenge you to do an irrigation audit of your system. In other words, set out a bunch of cans throughout and calculate how even the system waters. I think you’ll find that the uniformity is rather poor (which means you have to run your system longer to wet the dry spots thus wasting water). You can’t skimp on the number of heads and have good quality coverage. You need to have head-to-head coverage in all directions. You can use rotors successfully for large areas, but small areas really need smaller sprinklers. I feel sorry for your building and fencing that is likely already suffering water damage.

Also, your "backflow device" is well, sorry, it’s just a joke. That little loop won’t prevent backflow any more than a silly straw prevents you from sucking a soda pop dry. The next time you’re watering and a fire breaks out in your neighborhood or a water main breaks, all the dirty water, fertilizer, bugs, lawn chemicals, and dog feces puddling around your sprinkler heads will get sucked right back into your system and into your city’s drinking water. Did you get a permit and get your system inspected? I’ll bet not. You need the proper backflow device, properly installed, not one of those silly loops.

There is nothing wrong with doing it yourself, as long as you do it right. This is definitely NOT the way to do it.

Sincerely,
A concerned irrigation professional

Brandon,

I might have missed it in your article as I have not re-read it yet, but what were your flow rates and PSI coming out of your spigot?

Brandon,

A million thanks for this article! I never knew there existed a Flexible PVC pipe that\‘s available for underground lawn/irrigation use. In the years that have scouted for a possible DIY lawn irrigation project – I\’ve been always told to use the Poly(Hard) PVC pipes.

Like you, I am also an Engineer ( A Civil Engineer at that). In the 2 years that I\‘ve owned my house – I\’ve had to contend with dragging a hose and spending hours watering my lawn. With your "recipe" I am on my way to lawn watering bliss… I\‘ve just laid out my 1st circuit on my backyard (67\’x84\’) and I must say the "slotting" technique and use of the external spigot/faucet and the use of fewer (but strategic) placement of sprinkler heads really works.

I\‘ve suggested this "recipe" to some of my friends and I think it is spreading as the stock of PVC pipes in most of the Lowe\’s around my place have virtually ran out of stock.

Since the PVC Pipe is easy to work with, I am now planning to expand my system to include circuits for a mini herb-vegetable plot as well as my current and future clusters or trees, shrubbery and flowers.

Need I say – I have/will saved a lot of money? I was quoted $4500 for a Sprinkler system 3 weeks ago. With this DIY, I think I will go just a little over $700 including the timers…

Again, a million thanks!

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Question by Anonymous

I thought the article was great. I have a total twelve thousand sq feet of lawn to water. Would I have problems using your design to cover this much area? I like the design and it is my only option since the cost of a professionally installed system is way above my budget.

Thanks

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Filtered drains by nxs0152

Could you expand a bit on the filter drain installation?
Do they go on a "T-type" connector?

Thanks!
Norman

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Flex PVC question by nxs0152

Brandon:

I’ve started purchasing supplies for my DIY sprinkler system. A couple of the fittings weren’t stocked at my local Loew’s but after staring at the PVC wall until I though my eyeballs would pop out, a Loew’s "associate" finally took pity on me and helped me out with some effective substitutes.

My question has to do with this flex pvc pipe that you recommend. I want to make sure that I purchase the correct item. They had a couple of rolls of Orbit’s flex pvc but unfortunately it was only 1/2" so I started wandering to the next aisle and found these rolls of Silver-Line coiled pipe but it didn’t seem very flexible at all. Hard as a rock actually but it was dirt cheap at $14/100ft roll! The Orbit stuff seemed a bit softer but not by much. What do you think about the flexpvc product-line? It’s more expensive but it seems more pliable. Any thoughts? Anyone? Bueller? Fry?

Thanks!
Norman

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teflon tape by nxs0152

When making the "Sprinkler Head Assembly" you say to wrap teflon tape "around the 1/2" male NPT end of the riser prior to screwing it into…female NPT tee".
Now, when you screw the sprinkler head onto the other end of the riser are you supposed to wrap teflon tape around that end of the riser too?

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my experience by montyDIY

Thanks Brandon for the superb article.

I am installing my system now, and it is about 25% complete. The following are some issues that I have encountered so far:

(1) Unfortunately I was unable to find the Water Whiz flexible PVC pipe that you showed. In fact, my local Lowes and Home Depot do not sell underground sprinkler parts or accessaries. The only thing that I found in Lowes is some rolls of black "Poly" pipes, which require clamp type of fittings rather than the glue-on PVC fittings. Brandon do you have any opinion on using the Poly pipes? They are so much cheaper.

(2) I decided to buy flexible PVC pipes from flexpvc.com. The 3/4" pipe costs about $0.80/ft; but with shipping it becomes about $1/ft. Delivery took only a couple of days; however, they do not offer slower but cheaper shipping options. The pipes look good — strong and flexible.

(3) "Slotting" the lawn wasn’t quite as easy as expected, since my yard soil contains tons of rocks of all sizes starting at about 2 inches below surface. An L-shaped steel pry-bar turned out to be very efficient in doing the slot excavation. Without the pry bar, it would have been impossible to get the rocks out without severely damaging the lawn.

(4) I used Rain Bird 3500 series rotors for the most part. From what I gathered, they should be similar to your 32SA. The 3500 series rotor includes 8 nozzles of different sizes, each of which allows a different throw distance and flow rate. I found this feature very useful, especially in the beginning when I was not sure about the actual throw distance until I installed the first zone. Without this flexibility, it would have been hard to decide how far to space the rotors. Does the 32SA also have this feature?

(5) For a few locations where longer throw distances (30 feet /-)were needed, I used Rain Bird 5000 series rotors. My water pressure is pretty low … I think it is around 25 psi. So I had to be careful in using the 5000+ series since it requires larger flow rate. Generally I could not use more than two 5000+ series rotors per zone without sacrifising performance. The 5000 plus series also allows you to shut off individual rotors by just turning a screw from the top.

I have to go now, but will be back to add more as I progress. It’s been interesting, and thanks Brandon again for sharing this.

I just completed installation of the system. For a total lawn area of about 8,000 to 9,000 square feet, the system consists of 9 rotors divided into 4 zones. The total material cost is approximately $950, about one half of which goes to the flexible PVC pipes. A hefty $460 was spent to buy the 450 ft of pipes.

For the whole project, I probably spent over 10 days of work.
As I mentioned in the previous post, most of my time was spent to "slot" the lawn. Too many rocks were in the ground and it was a pain to get them out.

The yard is hilly and therefore the pipelines have many high and low points. As a result, I used 15 filtered drain valves for draining the pipes. I wonder if this would have resulted in any pressure loss if they do not achieve a 100% seal under pressure. On the other hand, I am still not sure whether these filtered drains would do a thorough job, as Rainbird on-line store discribes them as "reducing potential for freezing damage" but not eliminating it. I live in Connecticut and it gets much colder than Texas. I am thinking whether I should still try to pump out any remaining water in the system with compressed air before winter.

The Rainbird 5000+ series rotors worked just fine. In fact, they appear to be more sturdy and versutile than the 3500 or 32 SA, while costing only slightly more. It may require a somewhat higher water pressure and flowrate for the best performance. If you have plenty of pressure/flowrate and require a longer throw distance (30 ft or more), I think the 5000+ is the way to go. I used 3 of them plus 6 3500 models.

One lesson learned: if you have a hilly yard, do not place a sprinkler head at a location where the foot of a hill meets the flat ground. If you do that, the range of the sprinkler head can be severely limited and the grass around it can be shot down in a radius fashion, creating something like the Crop Circle in England.

One addition that I plan to make: The stripe of lawn below my deck is not covered by any installed sprinkler head. I am going to get a "side strip" sprayer head which is supposed to cover a rectangular area of about 5 ft x 30 ft. Does anybody have experience in this kind of spray head?

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Flex vs. Rigid by Anonymous

Brandon,

Very nice article. I already bought all materials except the flexible pvc. My question is "why can’t we use rigid pvc for the most part, but use flex pvc at the bends/curves to achieve same results?" Wouldn’t this be even more cheaper? Just wondering what your thought are before I spend a lot of money on the flex pvc.

Thanks.

I turned on the system for the first time this past weekend, and it worked just as it did last fall when installed. It appears to have survived a winter with a couple of snow storms, a serious freezing rain with 6 inches of solid ice on ground, and many sub-freezing days and nights.

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quick question. by Anonymous

How did you pass the pvc pipe connection across the sidewalk? Did you drill a hole in the concrete of the side walk or did you go over teh sidewalk?

Well, I’ve been quietly watching this little tutorial and it’s comment section for a couple of years now, so I guess I’ll toss in my 2 cents worth. This type of irrigation system is called a "supplemental irrigation system". As designed it is very inefficient and will waste massive amounts of water. However in some cases this is not an issue. There are many places in the world where water is still very cheap and abundant so I can understand why someone wouldn’t care about wasting it.

Note that Brandon’s yard is very level. This allows the water to flood over the surface of the ground and helps a lot to make up for the poor sprinkler head coverage that results from spacing the sprinklers way too far apart. If his yard was sloped he would have a lot of dead grass. It’s easy to see from his diagram of the sprinkler coverage that there are a lot of areas that the sprinklers do not even spray water onto. Running the sprinklers for long periods of time allows the water to flood the yard and water these areas.

I once installed a similar system using shallow pipe and cheap low quality materials at a rental house I was living in. Why spend lots of money on someone else’s house? I did use more sprinklers and spaced them much closer together for better water coverage. So there is a time and place for amost everything.

On the backflow preventer issue. The backflow preventer loop Brandon uses will not work and is a waste of pipe. This type of loop works with steam and drainage/sewer systems, but not with pressurized water (for the loop to work the contents of the pipe must be mostly air with just a little water, in sprinkler systems the pipe contains mostly water with a little air). In a sprinkler system pipe the water will simply syphon back through the loop if there is a flow reversal.

Here’s a better way to do the backflow prevention; add a hose bib anti-siphon device (backflow preventer) on the hose bib (or "spigot"). You can buy one at any hardware store. That will give you a true backflow preventer for just a few dollars. No need to do it wrong or spend a lot of money either!

Well, I don’t want to get into any arguements here, I just hope I have shead some light on the issues being debated. For some people Brandon’s design and methods will be just what they need. The important thing is to know what you are getting into before you start buying parts and installing them. Do a little research and examine your needs.

Regards,
Jess Stryker
Irrigation Consultant
www.IrrigationTutorials.com

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New Home by Anonymous

Hey Brandon, I have read through all of the articles and I can tell you know what you are talking about. I have just purchased a new inventory home on a premier lot the yard is well over 3000 sq. ft. in the back alone. My house is 2 stories, and around 2264 sq.ft. I am a little on the lazy side and not knowledgeable at all about irrigation systems. If I were to fax you a survey of my property and give you the required information needed, is it possible that you could supply me with all the materials I would need to cover the back yard and front lawn of my home (from lowes or homedepot).

Hey what can I say, I am cheap and lazy.

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Great article by Anonymous

Brandon, many thanks.

I just got an estimate this morning for professional sprinkler installation. The installer hasn’t even sent me the estimate yet…but I’m guessing it’s going to be over $2K as I have a large back yard.

If the bill is too much I may well use your system. I’ve dug trenches for a friend’s sprinklers (sucker moved to Germany so I can’t have him repay the favor), but your system beats running that "Ditch Witch" all day. After seeing your pictures & notes, I think I can do this for a lot less than a pro will charge. Again, many thanks… Dave

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Makes me tired by Anonymous

It makes me tired just looking at your article! I guess if you know what your doing, it’s great to install your own sprinkler system, but this article could easily be used as an incentive to just call a professional! Good luck with your system (great job!)

Brandon, I have been referring to this site for the past several days as I think about running my own sprinkler system, and the comments are interesting. I think the people who complain about the lack of full head-to-head coverage or water waste are missing the fact that people looking to install this type of sprinkler system are merely looking for a simple way to replace the manual time and labor of moving sprinklers. If you put an in-ground sprinkler exactly where you earlier had a mobile sprinkler, there is no additional water waste, just added convinience

I am planning on installing a run in my front yard this weekend. I have picked a flexible pipe at Home Depot called CFP Pipe, although I believe this to just be a type of poly pipe. The person workng there said I could use PVC connectors and glue with this pipe, so we’ll see how it all goes. I’ll try to remember to report back here and let everyone know my thoughts. I live in Middle Tennessee so the rocky soil compined with a hilly half-acre make me think that rigid PVC will be too difficult.

One question. Do you notice any pressure loss from using your timers? I tried timers for my hose sprinkler last year but the pressure loss was unacceptable. I hate to think I will end up with the same problem here.

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Replacing a head by Brandon

I received an email from a reader asking about replacing heads. Here is my reply:

I had to replace a head not too long after making my first installation, and it was fairly simple. When the ground was slightly wet around the head, I pushed the head side-to-side and back-and-forth to wallow-out some room around it. Then, I used a large wrench to grip the widest part of the head and unscrewed it. (Alternatively, you can just use your hands if you’re able.) When I had the replacement, I simply screwed it back in.

Great article! Have you ever thought of connecting this sprinkler system to a drip system for parts of your yard? If so, any advice you can provide would be greatly appreciated.

Thanks!

-ian

It’s eluding me, but I can’t find flexible pvc anywhere. Lowers, HD, both don’t have any, only polytubing which is inferior as it is meant for low pressure drip systems, not high pressure sprinklers. The ones I’ve found online to purchase charge humongous shipping fees. Any help?

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Two cents by thet0ad

Interesting article on how DIY install underground sprinklers. I’m a certified installer and find the biggest problems with self installed systems are the lack of proper design. This is key, because water is cheap in countries, such as the US and Canada however countries like Australia, well your lucky if they even let you water your lawn!

Two helpful hints: IMAGE A SQUARE BOX, place a sprinler head at each corner and you will be fine, break your yard into lots of different boxes and you should be good to go. Put turf (grass) on seperate zones from your flowers or plant material and you’ll be good to go.

Pipe size determines how many sprinklers you can put on a single line along with your WATER PRESSURE. Determine how many gpm each sprinkler head requires and divide it by the gpm the pipe is capable of. 3/4" pipe is around 8gpms and 1" pipe is around 12-15gpm. Don’t use smaller size pipe unless you are going with drip lines or micro sprays.

Install a back flow preventor of some sort, at minimum a dual check valve, they are $25-30 at your hardware store such as Home Depot.

gpm: gallons per minute

For more questions, you can contact me at info@next-rain.com

-Todd
Next Rain Irrigation Ltd. – we are a Calgary, Alberta Canada underground lawn sprinkler company.

I received the following inquiry via email:

I really enjoyed reading about your sprinkler system, so I decided to give it a shot. I have 2 issues. First, The flexible pvc pipe fits loosely in the pvc couplings and joints. Did you experience this?

I haven’t noticed any issue with the flex PVC fitting in the couplings/joints I’ve used. (You should be able to get a good feel for how tightly my joints made up by watching the example video in the article.) If you are sure the sizes match, then I suggest taking a sample to the hardware store where you bought the components to see if they can offer an explanation.

Also, the spigot pvc fittings detach when completely screwed in to the spigot The little joint pops out and separates from the spinning head. Has this happened to you? Over all any advice you offer on pvc cementing the pipe into the fittings would be appreciated.

I’ve never had that issue, either. Could it be you’re screwing in the fittings too far? They shouldn’t have to go on very tight to make a good seal on the washer.

As a side note, I’ve had issues with the spigot PVC fittings leaking from time to time. Usually, however, as long as the leak is very small (i.e., doesn’t affect the pressure so much as to compromise the sprinkler coverage and doesn’t cause my gut pain from any waste), I let it ride.

I hope you’ll come back and reply here if you find out anything useful in your search. Good luck!

0 Votes  - +
awesome~! by Anonymous

Oh thank you thank you. This seems like something I can do. You make it so easy to understand!

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Small Yards! by Anonymous

All I can say is you guys seem to have really small yards. My yard is 17,000 sqft. Subtract the house, driveway, sidewalk, and landscaping, and I’ve still got a good 14k sqft of lawn to water. I don’t see any way I’m going to be able to drive a system of this type from my two spigots.

On the flip side, my quote from a professional for a 10-zone, 42-head system is less than $3,500. Is your estimate of $3,000 for a 5,000 sqft front and back yard still accurate?

I was very new to the idea that a sprinkler system could be ran off of typical house spigot. I always assumed installation companies tapped into the line at a different point. I ran this system from two of my spigots and created six zones using a 2-way and 4-way splitter. The timers are set to run at different times so there is no issue with water pressure. To help cut costs I ran all of the straight lines with standard rigid pvc and only used flexible at heads and hookups. The system works great and I was able to do a 9,000 sq ft lawn for about $350 including all timers. Thanks for the info!!!

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LawnBelt by Anonymous

1) http://www.lawnbeltusa.com/index.htm

A lot cheaper, less work. OR

2) http://quick-snap.com/index.php

Same results but you have to get your hose in and out for #2. If you get spigot timer for either one it works great.

3) Go to the local Walmart, get the spike sprinklers, buy some (as many as you need for the number of sprinklers)25’ water hose (Connection between the sprinklers), get some T’s and last but not least a spigot timer. With the spike sprinklers the top half comes off and leave the spike in the ground. This is for a smaller yard using 3 or 4 spikes.

Thanks for the tips. I used your guide as a basic one. My steps:

1. Used my survey and Google Sketchup(free) to map out my sprinkler head coverage.

2. I decided on popup sprayers, rather than rotor heads. I also decided to used mostly hard PVC and dig full trenches, since I tore out all of my old grass (weeds) and it was WAY cheaper than flexPVC.

I used flex PVC from Lowes to go to heads and any bends. I also bought a $5 backflow preventer that is threaded for spigot threads.

Overall, it went down pretty fast. I tried an electronic timer that was really cool, but it restricted flow so much that I was unable to use it.

Thanks a lot for the tips. I have never used PVC and have never done anything like this before.

I have been enjoying a good service of the system I installed in 2006 using essentially the same technique Brandon shared with us in his classic article. No major issues, that is, until now.

Yesterday, I noticed a significant reduction of pressure in one zone, and subsequently identified a leak in the pipe route. I dug out that section, and was really shocked to see that severe cossion has been going on. Within a length of about a foot, there were 3 holes, each approximately 1 millimeter in diameter. There were also other marks of corrosion on the outer wall of the pipe, but most of them have not corroded all the way through yet, except for the 3 holes. I went to google for the corrosion resistnce of the PVC, and found no clue.

This section of pipe is at the edge of the lawn, adjacent to an asphaltic driveway. It also happened to be in a spot where the snow would pile up everytime I had to shovel the snow off the driveway. And I do get quite a bit of snow here in Connecticut.

I started to wonder about two possible causes for the corrosion: (1) perhaps the chemicals from the asphalt is corrosive to the PVC, and (2) perhaps the de-icing salt that I sometimes put on the driveway had pile up together with the snow and leached down into the soil around the PVC pipe, causing it to corrode. Before now, I always thougth that PVC is resistant to all of these chemicals. But obviously not … Or, could it be some kind of insects in the soil that had been nibbling on the pipe? Bizare indeed!

I hope this is a localized problem … coz if not, the whole system I put in at the expense of a ton of sweat could be in an advanced stage of deteriation leading to a complete failure!

Can anybody share some knowledge on this aspect? It will be greatly appreciated, for obvious reasons! And I suppose all of you out there reading this would be interested to know too!

Brandon: I want to employ this system, but only to water my shrubs, plants, and garden areas. Is it better to just get the popups and plan to water the entire area including the lawn, or can I pick sprinklers that just spray in one direction, into my wanted areas? My lawn always gets enough water, except once in four years and I can hand water if it happens again, but with my garden, the wife’s flower garden, and all our shrubs and plants, hand watering is out of the questions.

Rod from Indianapolis

I received this question elsewhere:

I cannot find the flexible PVC you used. My lowes has two types that are close. I have one question though, the two they have are very different. One of them is 1" diameter with a 3/4" inner diameter and seems very thick (almost rubbery). The other is a 3/4" flexible pvc that is pretty thin and says it can handle 100psi. Which one sounds right to you?

The kind I use is rubbery – so thick that it’s difficult to work with if it’s cold. (Nothing sitting in the sun for an hour or two won’t fix, though.)

I’ve seen another kind of black, flexible tubing at Lowe’s, but it is thinner and feels more plasic-y. I believe that’s for lower pressures and I don’t know if it will interface properly with PVC glue and fittings. (I’ve never used it before.)

That’s actually a good way to check if it’s what you want: Grap a PVC fitting and test it on the end of the roll.

I hope that helps.

0 Votes  - +
Not convinced by Anonymous

I guess this is clever, but a few comments….

PLEASE get a PROPER backflow preventer. That loop of pipe is NOT a backflow preventer, it’s just a loop of pipe. You’re risking poisoning yourself, your family, and your neighbors.

I’m not convinced of the increase in value. In fact, if I was looking for a house and saw this sort of cobbled together setup (in-ground sprinkler run off the outside spigot? Really?) I’d just cross it off my list, because I’d be afraid of what other stuff you’d done half-assed on the house.

You must be somewhere comparatively warm. I have an actual professionally installed sprinkler system and it’s way above the freeze line. Of course, my freeze line is 42".

Speaking of the professional sprinkler system, when I had them move one of the heads, guess what they used? Flexible black plastic piping and a spade to open a slot in the ground. In fact, that’s what they sell at Home Depot specifically for lawn sprinklers. It’s called (I don’t know why) “Funny Pipe.”

I used the same techniques to install 6 heads in my backyard. My yard is rectangular, with 3 heads on the left side, 3 on the right. I have them setup as zone 1 and 2, using a timer.

Zone 1 goes off for 20 minutes and covers up to the right side heads. Then zone 2 goes off for 20 minutes and covers up to the left side heads.

This system has survived 2 winters so far, with no problems. I did break two heads with my mower though (need to be more careful). this system does a great job of coverage, and has been very reliable.

I caution everyone about the way the backflow preventer is displayed. Spend the money and do it right, that looped piece of pipe will not do the job properly.

Overall, these instructions gave me a very good sense of what I needed to do and the inspiration to see it to completion.

I’m now tackling the front yard, using the same techniques.

-2 Votes  - +
John by Anonymous

This is a complete joke.
start over and do it correctly
and get it to at least up to code.

and it looks like a four year old layed it out.

have a nice day.

0 Votes  - +
Great Job by Anonymous

Everyone is a critic and an expert. I think you have a wonderfully engineered solution. The goal of the project was to simply and cheaply apply water to the grassy portion of your yard and you are 100% successful. That is an engineered solution. If you want to develop an expensive, time consuming, overly designed, full of regulated nonsense solution, you could have done that. That is a government solution. The only replies you have to over-engineer the system are from people who are neither an engineer or have a monetary interest in your failure. This is putting water on a lawn people! Does not require a doctoral thesis. I appreciate the knowledge you shared here an plan to install a similar system when I get the time.

What are your thoughts of using a 4 way (3/4") cross connector at the sprinkler head (instead of the 3-way tee connector) and installing a filtered drain at the bottom and using the (3/4" Soc x 1/2" female NPT) Bushing on the top to install the sprinkler head. That would be less work than having to install the filtered drains all along the low points of the line… Would installing the filtered drains directly below the sprinkler heads cause any issues? Anybody know the answer to this?

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A great article by Anonymous

Somehow while looking into an add a zone for work, I stubbled upon this article. It was great, except too many had negative to say. I did the very thing about 8 years ago, except I didn’t get into the drawing detail too much. I already new how the overlap works and the nozzels I needed. The one think I did a little differantly was I used my ols water hose. Found the 90 degree hose barbs at the farms store, hose clamps, made the narrow ditch like you did andI am in business. Another part I added later was to disconnect from the from faucet and bury pvc to the back faucet. Now for the fun part. Had an old Hot tub I need to get rid of. Took the motor and pump, plumbed to the back faucet. Well, you can probably picture the rest. Now with an electric valve in line and a timer I can just swith valves from front to back and I just love to most even coverage you can imagine. Hope anything I wrote helped someone.

Thank You Brandon!!

I Installed my system in 2009 and it still works great. I live on sandy soil and something needed to be done. I did not have the 3k or 4k to dish out, this cost me about $650 and my lawn is now one of the nicest in the neighborhood. I found all the materials I need at my local menards. I used the black flexible poly pipe and all fittings were done with stainless hose clamps. I have 4 zones with three rotor heads per zone. I use a 4 way manifold on one hydrant, and a 2 way on the other. This allowes for the timer(s) and a garden hose on each hydrant. As others have mentioned I set the timers to go off at diffrent times, usually in the middle of the night. As the article states I do not have 100% coverage and perfect overlap. However I could never achive the watering results I get now with just plain old sprinklers, and I don’t miss draging then all over the yard either.

Couple Things

Backflow Preventor – Brandons loop – I researched this online . The method is correct, the execution is not – the loop would need to be higher than the house to work. Again I researched the backflow stuff, I do want to be safe. Seems to me, having a backflow event would be rare. If it happend, in order to suck up whats in the lines, your hydrant valve would need to be leaky and you would need water in the sprinkler lines. Now if you install drain valves in the lines, they should be empty, thus just air would get sucked up. However if the backflow should occur while you are watering, the line is opened and I see where this could cause a problem. So I installed a hose bib vacum breaker at the bottom end of every timer. This will break the vacum if backflow should occur. They are inexpensive and it is easy to see they are in working order. Every time the valve is shut off they shoot out a little stream of water.

Manifold/Splitters
As I got into this project I realized quickly that my water volume and pressure was importnt. Especialy when doing this with minimal heads and zones. I tested pressure and volume in the begining. After hooking everthing up I noticed I was not getting water throw from the heads I was expecting. Two things were affecting the flow and pressure. The vacum breaker, and the hydrant splitter, were both resticting my water flow. I was not willing to give up the vacum breaker, But I was able to make my own splitter/maniflod using sprinkler sytems fittings and 5/8 heater core hose from the auto part store. Doing this gave me back some of the flow that I lost.

In the end. It was a bit of work, but I like the do it yourself projects. My yard looks great, the kids love playing on it. I figure I saved about 3k and I no longer have to waste my time dragging hoses and sprinklers around.

Thanks again to brandon for taking time to post this online. You’ve made my summers much more enjoyable.

First, I found some of these techniques useful.

As an engineer I’m very disturbed by others calling this engineering. This is very prime demonstration of technician hands on know how as is most DIY. One of the comments is correct, engineering is not about perfection, it’s about making trade-offs and coming up with solutions to problems. However it is also firstly about ethical designs and secondly about solving the problem. An effective way to take out the trash is to dump it on the neighbor’s lawn and make them pick it up, it is not ethical.

As mentioned by some with something to lose and some without, this style back flow prevention does not work as shown and you will risk poisoning yourself, your family, and your neighbors. Go buy a back flow prevention device that meets code specifications. In my city they follow all standard plumbing recommendations from International Association of Plumbing and Mechanical Officials with the exception that they require very specific standards for back flow prevention devices. I’m quite sure my city isn’t the only one.

Get your install inspected and follow the local code for sprinkler systems! there are very good public safety reasons for the code.

-Signed a concerned engineer with interest in DIY sprinkler systems with no connection to professional installers or back flow prevention manufacturers.

Here is a very nice reply by someone from flexpvc.com
http://www.manhattanreefs.com/forum/general-discussion/38569-flex-pvc-safe-use-4.html
i spent 2 hours at home depot trying to find a proper pipe. They have a flex pvc in electrical section but when you try to use the regular pvc fittings, they are too loose. This article explains why…
Anyone else found a good place to buy flexible pvc? Or any other hose with barbed fittings?

Hi Brandon,
Your article is extremely helpful, thanks. I found a website called LawnBeltusa and was wondering how a sprinkler from them would compare to doing it myself as describe in your article?
Thanks again,
YM

Thank you very much for this post. I have done a ton of research and your post validates what I think would work. As mentioned before I would get a tap backflow thing.
Other than that I have to say well put together and the pics help a ton. Awesome from my view.

Thanks again.

I’m looking at doing a small self installed system at my cabin, it’s a small yard but very sandy and I’m not there all the time to water so I’m hoping an inground system will help. I really like what you’ve shown but my concern is that I don’t have city supplied water, I have a pump in a well. My concern is will hooking this system to the spigot damage my pump by making it turn on and off all the time? I have an irrigation system (very large, 75 heads, 15 zones) at my home which also has a well and pump and it was installed by a professional and is connected ahead of my pressure tank and I believe that is to cause the pump to run continually and not on and off. At my cabin I’ll only have two zone and 2 or 3 heads on a zone. I’m just concerned about my pump with hooking to the spigot which is after my pressure tank. Anyone have any thoughts on that?

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