Quick Summary: Start by installing the sprinkler riser on the lateral pipe outlet. Then the sprinkler is screwed onto the riser. Adjust the sprinkler to be in the desired location and perpendicular to the ground surface. Position sprinklers at the edges of the irrigated area about 4″ away from hard surfaces like sidewalks and driveways. If growing a new lawn from seed make provisions to prevent the water spray from the sprinkler from washing the seed away. Details follow!
This page outlines the minimum requirements, along with tips and tricks, for installing the pipes, tubes, and wires for your new irrigation system. Summary of major points:
- Wet areas to be trenched a couple days in advance.
- Consider hiring someone to dig the trenches.
- Install mainline pipes 18 inches deep.
- Install lateral pipes 8 to 12 inches deep.
- Make provisions for winterizing the system in cold winter climates.
- Use proper methods for gluing PVC fittings to prevent future leaks.
- Use good quality fittings for PEX.
- Don’t forget to install wires in the trenches!
- Sleeve the wires if you have aggressive critters.
Where and How to Connect Your Irrigation System to Your Water Supply:
This page provides some specific rules, tips, and techniques for tapping into a house water supply pipe for a new irrigation system. Where and how you tap into the water supply can be critically important, not just for the proper operation of the irrigation system, but also for the preservation of your sanity!
There are special safety issues unique to irrigation installation. It doesn’t save any money to install your own system if you wind up in the hospital, correct? This is not by any means a complete list of safety precautions, but it should get you thinking the right direction.
Remember, your brain is the best safety device you have, don’t start work without it! Common sense and staying alert can avert a great number of accidents. For example, when you get tired, take a break.
First Call 811 or click the logo below.
- USA: Online request form for utility location throughout entire USA.
- USA: utility locator websites for entire USA.
- Canada: Click Before You Dig service.
- Australia: dial 1100.
- UK: here’s a list of gas & electricity suppliers.
- UK: OpenReach telecommunications contact.
IMPORTANT! It doesn’t do any good for them to mark the utility locations if you don’t understand how to read the marks they make. Often the mark they make is not directly over the utility. You need to know how to understand the mark that means “the wire is 5 feet north of this line” or you will be it trouble. Here’s links to a few articles to help you:
More safety tips:
- Never get into a trench or hole that is deeper than your knees, and never sit or lay in a trench. Trenches that appear stable can collapse without warning. Remember that if you are knocked unconscious you will not be able to pull yourself out. All that needs to be buried is your head and its all over!
- Never leave trenches or holes open when you aren’t working. Avoid trenching more in a day than you can finish and backfill. If you can’t backfill the trench then cover them with boards or rope them off, even if you’re just going to lunch.
- Take it slow and easy. Rushing leads to injuries and mistakes. I have a hard time with this one myself. I always push harder and farther than I should. If you injure yourself and have to take off work for a day or two, you will loose all the cost savings you gained by doing it yourself. Know your limitations, and get help for lifting or moving heavy objects. Be especially cautious with digging and operating any machinery that vibrates or pulls you. Both can stress your muscles without your realizing it. You don’t know you’re hurt until a few hours later. Wheelbarrows are another one that can get you unexpectedly. If the wheelbarrow looses balance and starts to tip it is usually best to just let go. You can reload it in a few minutes, but if you pull a muscle trying to hold it upright, it can lay you up for weeks.
- Wear proper work clothes. Wear a back brace (you know, one of those girdles the employees wear down at the home improvement store) while lifting and digging. Wear heavy closed-toe shoes, and long pants to protect your legs. Guys- if you get PVC cement on your legs you will find that removing it is a very unpleasant experience.
- Don’t get sunburned! Wear a hat and sun block if you’re not accustomed to working outdoors. You’re probably going to be sore after working with muscles you don’t normally use, so don’t add a sunburn to your misery!
- Drink lots of liquids. Save the beer for after you’ve finished working for the day.
- Don’t work alone. Have someone else around who can go for help in an emergency.
- Wear gloves to minimize blisters on your hands. Hand lotion is another must have item, handling dirt dries out your hands and makes them crack. When you get PVC cement on your dry, cracked hands it stings. To remove the PVC cement from your hands use acetone. If you think the PVC cement stings wait until you feel the acetone!
- Don’t leave your tools laying around. You’ll feel like a idiot when you have to go to the hospital with a broken nose because you stepped on a rake and the handle flipped up and hit you in the face.
- Keep children away from the work site. They love to play in the piles of dirt, but it just isn’t safe. Lots of kids are injured each year at construction sites.
- Watch out for overhead wires. You don’t want to knock down someone’s telephone wire with a piece of PVC pipe, and of course if you’re using metal pipe and bump into a bare electrical wire…
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Standard threaded fittings as used in most irrigation and plumbing are very slightly tapered. This creates a more positive seal as the male thread is twisted into the female thread, to prevent leaks. So the diameter of the male threads increases slightly at the back of the threaded portion, while the diameter of the female threads decreases further inside the fitting. In most cases this taper is not sufficient to create a reliable seal, so a sealer is used. For irrigation systems the recommended sealer is PTFE thread seal tape (often called Teflon® tape.) Do not use “pipe dope” (liquid or paste type sealers) on irrigation systems! If it comes in a tube or bottle, don’t use it. Look on the bottom of many sprinklers and you will see the warning “Don’t use pipe dope”. This is not an insult aimed at people who use pipes rather than tubes! When pipe dope or paste works it’s way inside the pipe (which it will) the water will carry it to the valves, drip emitters, and/or sprinklers and clog them up and ruin them! So the sprinkler manufacturer is warning you not to use them. Only use PTFE tape type sealers. If tape gets into a valve or sprinkler it can be removed and the damage is not permanent.
Using PTFE Thread Sealant Tape (Teflon® Tape)
When joining male and female threaded fittings, put a nice thick layer of PTFE thread seal tape on the male threads before you screw them into the fittings. Pull the tape tight onto the male thread so that the tape molds into the threads. Wrap it in the direction of the threads so it doesn’t unwind off when you screw the fitting on. (If you are looking at the end of the male fitting that would be clockwise.)
How much tape to use? The old standard was “3 wraps”. However now they are selling low-cost PTFE tape that is thinner and requires more wraps. When you have enough tape on the male threads the shape of the threads will be just barely visible through the tape. I personally prefer to err on the side of using too much tape, it is not fun to find you didn’t use enough after the water is turned on and you discover a leak.
Connecting the Fittings
Once the tape is on the male thread screw the male thread into the female threaded fitting. If the joint is between two metal pieces put a wrench on it and tighten it as tight as you can get it. If one or both of the fittings is plastic just tighten it by hand. If you are an average guy or gal you can add one more full turn using a wrench after it is hand tight. If you have ever been called a gorilla for your strength or grip, stop at hand tight. Over-tightening plastic fittings splits the female fitting, resulting in a leak. But not tightening them enough also gets you a leak.
Avoid joining a male metal threaded fitting to a plastic female threaded fitting. This will be a disaster if you are not very careful. The male metal end does not give at all, and the female plastic fitting is likely to split open unless it has heavy reinforcement. If you must join male metal to female plastic, use lots of PTFE tape and hand tighten only. No wrenches!!
High density polyethylene (HDPE, trademark name is Marlex®), street ells often don’t need PTFE tape to seal, but I still use a little on them. It will not hurt to use a couple of wraps of PTFE tape on HDPE fittings. HDPE is a shiny, black, plastic that is slightly softer than PVC and feels slightly “oily”. HDPE is good for places where the fitting needs to be able to rotate and not “seize up” over time. Metal, PVC and PBS plastic threads will seize up and not turn easily once assembled. The HDPE fittings are idea for sprinkler risers where you want the threaded joints to remain pliable and able to move and absorb impacts. Warning: The black barbed insert fittings used to connect to flexible tubing risers (often called “Funny Pipe®”) are not HDPE. HDPE is seldom, if ever, used for any fitting with barbs. This is because the slippery surface of HDPE makes the tube slide off the barbs! If it has barbs, be sure to use PTFE tape on any threads.
Rule of thumb: If you can’t scratch the plastic with your fingernail, use PTFE thread seal tape on the threads!
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Anti-siphon valves are the primary type of valve used for residential irrigation systems. There are several very important rules that apply when you are using or installing an anti-siphon valve. They MUST be installed in the correct way or they will not work!!
Quick & Dirty Summary
- Anti-siphon valves must be installed 6″ higher than the highest sprinkler head or emitter outlet.
- The anti-siphon valve inlet pipe must meet local plumbing code requirements for exposed pipe. Generally that means using metal pipe such as copper, brass, or galv. steel.
- No other on/off valves may be installed on the downstream side of an anti-siphon valve.
- Anti-siphon valves may not be left “on” or “open” for more than 12 continuous hours at any time.
- The optional “Flow Control” feature is worth paying more for. It will probably save you more time and money than the extra cost it adds to the valve. Plus most anti-siphon valves without flow controls are poor quality.
- To avoid nasty surprises, avoid using a water supply for your irrigation system that passes through a house inside the walls, under floors, or through the attic.
Keep reading for in-depth details and answers to “why?”
Water-proofing your irrigation system’s wire splices is one of the most critical tasks in any installation or repair that involves wire splices. The splices need to be completely water-proof. Taping them up with electrical tape will NOT work for this! The electrical tape will allow water into the splice as it becomes old, brittle, and the adhesive on it dries out. If you don’t water-proof your splices it WILL cause your valve to fail! Don’t save a buck on a wire splice and ruin a $20 valve! I’ll explain in detail why waterproofing is so important later, first let’s get down to the details on how to make a good waterproof wire splice.
General Things That you Need to Know about all splices!
Caution: The methods described below are intended for low-voltage wires of 24VAC or less, such as those used in typical irrigation system controls. They should not be used for higher voltages.
DO NOT BURY SPLICES directly in the ground. Put a box around them to protect them and to help you find the later. A small plastic utility box works fine. Glue a large steel washer to the bottom of the box lid using epoxy. This will allow you to find the box with a metal detector if grass grows over it. Splices are the most likely place a wire will short out in the future, so a box makes the splices easier to find and repair.
2-wire irrigation systems: These are a newer type of system that uses only 2-wires to control all the valves. The irrigation controller sends a signal through the valves to a decoder at each valve. The decoder then allows power to the valve solenoid only when told to by the controller. These types of systems depend on electrical “signals” sent from the controller through the wire to the decoder. Any voltage leak at a splice can severely impact the signal and cause the system to malfunction. For this reason splices for 2-wire systems need to be made much more carefully. Many of the 2-wire manufacturers have specific splice methods they require be used in order to protect your warranty. Be sure to use these if required!
Not sure if your system is 2-wire? As i write this in 2013, 2-wire systems are seldom used on residential systems, but they are also gaining popularity and will probably start showing up soon, first on larger systems. The controller case normally will be clearly labeled as “2-wire”. A 2-wire system will also have a “decoder unit” installed on the wires at each valve. Standard irrigation control systems have two wires going to each valve. But in a standard system one of the wires goes to a single valve and only that valve. So if you have 4 valves there will be 5 wires (1 common shared by all the valves, + 1 individual wire to each of 4 valves = 5 wires.) On a 2-wire system with 54 valves there would be only 2 wires and each valve would have a decoder unit installed on it. The presence of a decoder to be installed at each valve is the best way to tell if it is 2-wire.
The best way to make the splice is to use special water-proof splice connectors that you can buy at any hardware store. These are made for sealing outdoor wire connections and work very well. There are many different styles and types available.
Water-Proof Twist On Connectors – “Nut” Style or “Wing” Style
Most of the connectors currently used by pros consist of an twist on type wire connector that is filled with a water sealing grease. Sometimes these are called water-proof “nut” or “wing type” connectors. These are inexpensive and very simple to use. Here are general instructions for use since a lot of these inexpensive connectors are sold without instructions. If instructions came with the connectors please use those instructions, as they are intended for the actual connectors you bought!
- For every 3 connections you need buy 5 connectors. Why? Because you will probably make several bad splices, and you will have to remove those connectors and toss them in the trash. They can’t be reused because when you remove them a lot of the sealer comes out with the wire. (If you look close most connectors actually say “do not reuse” or similar language on them.)
- Start by stripping the insulation off the end of the wires to expose the bare metal wire. Do not strip off too much insulation, the exposed bare wire should be about 1/2 the length of the connector body. You can splice 3 wires together easily using a single connector. It’s OK to put 4 or 5 wires in a connector, but be warned that it gets a lot more difficult getting the wires to stay in the connector when you use more than 3 wires.
- Place the bare ends in one hand and using your other hand, align the wires side-by-side, so the ends of the bare sections are lined up together. Those ends need to all go into the connector together at the same time, so hold the wires tight and don’t let them slip out of position. Do not try to insert an additional wire into a wire connector that already has wires spliced together in it. You need to remove all the wires and redo the splice to add more wires.
- Push the connector down over the bare ends of the wire. Twist the connector clockwise to screw it on. Hold the wires firmly in position as you twist the connector over them. The connector has threads, a spring, or barbs inside it that will grab the wires and cinch them together tightly as you twist it on. Stop twisting when you feel substantial resistance.
- Hold the connector in one hand and tug on each of the wires with the other to make sure the wires are secure and will not pull out. If a wire feels loose or pulls out, disassemble the entire splice and try again. Use a new connector as some of the sealer will probably be lost when you remove the connector, and it needs all the sealer for a good seal. If the wires still pull out after another try you are probably using the wrong size connector.
- Finally make a visual inspection of the splice. The insulation on the wire should be fully inserted into the sealer gel or grease. No bare wire should be visible. That’s all there is to using twist on wire connectors, they are very quick and easy.
The connector size is important when using twist on connectors! Be sure you buy and use the correct size connector for the wire sizes you are splicing. The package will list the various wire size combinations that the connector works on. The connector colors indicate the connector’s size and most are standardized. Here are some general guidelines. Warning: There are some brands that do not follow these color guidelines so double check the instructions on the package!
Connectors for #18 wire. Most residential irrigation systems use #18 size wire, this is the size of most of the multi-wire underground irrigation cables sold in hardware stores. Unfortunately the colors for these connectors are not standardized. Most I have seen are dark blue or black. Make sure it says it will connect 2- #18 wires.
Connectors for #14 & #12 wire. Larger irrigation systems and commercial irrigation often use individual #14 wires. Sometimes #12 will be used for irrigation systems with very long distances between the controller and the valve. Most often these connectors are yellow. Note: Most of the yellow connectors I have seen will NOT connect a single #14 wire to a typical valve solenoid wire. For this you will probably need the smaller #18 wire connectors above.
Mechanical Clip Style Non-Stripping Connectors
Clip style is a catch-all name I use for the various types of connectors that use a mechanical clamping system to grab and bite into the wire. Typically with this type of connector you push the wire into a round slot on the connector, and then squeeze some type of clamp that bites into the wire to hold it in place. Some require pliers to squeeze the clamp into the wires. The most popular of these types of connectors for irrigation use is the Blazing Snaploc BVS Series wire connectors and the 3M Scotchlok 314 series connectors. These connectors are more expensive but make a very secure connection almost always on the first attempt. You won’t need to buy nearly as many extras for bad splices.
Container Type Connectors
These connectors are a two piece, two step system. You connect the wires together using either a standard twist type wire connector, a crimp sleeve, or even soldering the wires together. Then you shove the splice into a container filled with a water-proofing grease or jell and snap a retainer lid closed to hold the splice inside the container.
A variation on this type of connector is the original waterproofing method used back when I started in the business. You mixed a 2-part epoxy resin in a small plastic envelope and then shoved the splice into the envelope so it was covered in resin. The resin was allowed to harden creating a solid water-proof seal. Unfortunately the resin was a carcinogen. I don’t think these are sold any longer.
Q. How do I calculate sprinkler risers losses in a sprinkler zone where the risers are extra long, 3 ft or more above ground? I have 10 risers in a zone for my proposed sprinkler irrigation system.
A. If you are using my Sprinkler System Design Tutorial and a standard riser of the recommended size, then you don’t need to worry about pressure lose in the riser, the tutorial has friction loss for the risers built-in to the formulas it uses. So you can ignore the riser pressure loss. Some standard risers are shown on the page on Sprinkler Risers in the Irrigation Installation Tutorial. The recommended size for a riser? In most cases it should be the same size as the threaded inlet on the sprinkler. But please actually read that page on risers, as there are some exceptions to that rule for certain types of standard risers!
OK, I realize that didn’t answer your question, you are asking about a non-standard riser that uses a long pipe to hold the sprinkler high above the ground. In that case you must calculate what the friction loss will be in the longer-than-normal riser pipe. (In this case that would be the 3 ft long pipe you described in your question above.) To do that you simply use the same friction loss spreadsheets that you use to calculate the friction loss in any other pipe. Just use this link to get the proper spreadsheet from my website for the type of pipe you are using. Then open the spreadsheet and on the first line enter the pipe size, GPM of the sprinkler you will install on the riser, and the length of the riser. Enter an error factor of 1.4 rather than the default 1.1. This is because even your “longer” riser is shorter than the typical pipe length that the default error factor is based on. Now read the friction loss. That’s it, you have the friction loss for your non-standard riser! Don’t worry about the fittings like ells and couplings that are part of the riser, that is part of what the error factor is compensating for.
When adding the riser friction loss into the total friction loss calculations for your whole sprinkler system, just add in the loss for a single riser. Use the friction loss value for the riser that has the highest friction loss. (This is most likely the one with the highest GPM sprinkler, or it may be the longest riser if you have different riser lengths. You may have to calculate the friction loss for several different risers to figure out which of them has the highest loss.) Why do you add in the friction loss for only one sprinkler, rather than the combined loss for all of them? Because as a single drop of water goes through the sprinkler system it only goes through one sprinkler, not all of the sprinklers. You have to think about the water as a collection of millions of drops, not as one solid body. So the pressure loss is what a single drop would experience as it travels through the system. As a drop of water enters the sprinkler system it travels through a water meter, lots of pipe, a valve or two, then it finally blows out through a single sprinkler onto the landscape. The pressure loss calculation for the whole sprinkler system is determined by what the worst case pressure loss values would be for a single drop of water traveling through the sprinkler system.
OK, so you calculated the friction loss, but what if it is a really high value, or maybe the calculator complained about the velocity being to high. In this case you need to use a larger size pipe for your riser. For the velocity in a riser you can go all the way up to the 7 ft/sec maximum without too much risk. Velocities in the marginal “use caution” zone are generally OK for risers. High velocity in a riser will seldom cause a water hammer problem, unless you are using a special type of sprinkler that has a solenoid valve built in to it. Those sprinklers are called “valve-in-head sprinklers”, they are very expensive, and are mostly used for golf course greens.
The Sprinkler Buddy is a cone shaped plastic collar that fits around a sprinkler head to prevent grass from growing up next to it. It serves two purposes, the first purpose is to keep grass from growing over the sprinkler head, thus make the sprinkler location obvious in the lawn. When using heavy power mowers this allows you to mow over it while avoiding hitting and breaking the sprinkler heads. The old standard method of keeping sprinklers visible is to trim around them each week with a line trimmer to remove the grass around them. Obviously this is a lot of work that is not needed when the Sprinkler Buddy is installed around the sprinkler. A second use for the Sprinkler Buddy is as a sprinkler head stabilization device. According to the manufacturer, the wide cone shape helps keep sprinklers in an upright position. Another advantage of the Sprinkler Buddy that isn’t heavily promoted by the company is that it keeps tall grass away from sprinklers with low pop-up heights, again reducing the need for frequent grass trimming around the sprinkler head. The Sprinkler Buddy is made to fit on all pop-up sprinklers, both the smaller body spray types and the larger residential rotors (up to 2.5″ diameter, and maybe a bit larger.) It is a product of RyRo, Inc. of Florida, USA.
The Sprinkler Buddy is made of a semi-rigid, UV protected, plastic material that is soft enough to cut with a pair of scissors, but rigid enough to maintain it’s shape. To install you start by cutting away the grass from around the sprinkler in an area just large enough to fit the Sprinkler Buddy into. Next, the sprinkler head is unscrewed from the pipe (the proper name for this pipe is a “riser”) to remove it. Using scissors, simply cut slits in the Sprinkler Buddy base that are large enough to allow your sprinkler to slide into the bottom of the Sprinkler Buddy. In a few situations you may also need to trim the edges of the Sprinkler Buddy to custom fit it to unique situations, for example if the sprinkler is very close to a sidewalk or wall. Finally the Sprinkler Buddy is pushed onto the sprinkler head, and the head is screwed back onto the pipe. A set of complete installation instructions are on the Sprinkler Buddy Website.
I installed two Sprinkler Buddies into a professionally maintained condominium complex in Portland, Oregon during the summer of 2011. The Sprinkler Buddies were installed per instructions over existing brass sprinklers, one was a flush mounted no-pop-up spray head, the other was a low pop-up with gravity piston retraction. (I need to insert a disclaimer and warning here. Both these sprinklers are older types, they were state of the art in the ’50s and ’60s, but are still found on a lot of older sprinkler systems. While still available for sale in stores, these heads are an antiquated design that are high maintenance and water wasters. As a professional my first recommendation for these sprinklers would have to be that they be replaced with new plastic-body pop-up type sprinklers with at least a 4″ rise height. See my recommendations and reviews of sprinkler heads.)
The Sprinkler Buddies immediately performed as expected, they held back the grass that had previously interfered with the sprinkler’s spray patterns, allowing for better water coverage. The maintenance caretaker also reported that he no longer had need to trim the grass back around those heads as he does with all the other heads on the property. He did note that periodically some bermuda grass would grow up between the sprinkler body and the sprinkler buddy. This appeared to be an infrequent issue that might require a check of the sprinkler once or twice a year in order to remove any grass growing inside the Sprinkler Buddy.
The Sprinkler Buddies were left in place for the winter and rechecked in the spring and again in the summer of 2012. Upon examination in spring we found that the Sprinkler Buddies had each filled with leaves and pine needles over the winter. The leaves and needles were easily swept out using an old broom, and an examination showed no damage from frost or snow to the Sprinkler Buddies. Further, no grass was growing inside either of them and no grass trimming was needed around them before restarting the sprinklers. By way of contrast, we could not even locate the other sprinklers in the lawn that did not have the Sprinkler Buddies. Despite having the grass trimmed well away from them in the fall, these sprinklers were now completely covered with grass that had grown during late fall and early spring while the sprinklers were shut down for the rainy season. We had to turn on the sprinkler system to locate the other sprinklers and then mark their locations so the grass could be trimmed away from them.
The Sprinkler Buddy worked as promised. It clearly marked the sprinkler locations making them very visible, and it looked attractive if you are into that edged sprinkler look. While not my thing, I have met a lot of people who love the look of a clean cut edge around their sprinkler heads, and for them the Sprinkler Buddy will be something they love. It will create a near perfect edge of uniform size around each sprinkler head. In my tests the Sprinkler Buddy was also very effective at reducing maintenance at the sprinklers where we installed it, saving about a minute a week in grass trimming effort for each sprinkler. It was also a huge labor saver at the spring season sprinkler system start-up, saving about 10 minutes of time per sprinkler (for sprinklers without the Sprinkler Buddies the caretaker had to turn on each valve circuit, located and flag the sprinklers, then return later with the string trimmer to trim away grass from them.) The caretaker was able to mow over the Sprinkler Buddies with his rotary mower without damaging them.
On the minus side the Sprinkler Buddies were a bit harder to install than I expected, mostly because I needed to remove the sprinkler heads and they were rusted in place. Some people have stated that they successfully have installed the Sprinkler Buddies without removing the sprinklers. I did try this and I was not successful at installing the Sprinkler Buddy to my rather high quality standards (ie; I was able to get it on but I didn’t like the way it looked when finished and it wasn’t nearly as stable.)
The Sprinkler Buddy is made to cure a problem that you really shouldn’t have. (Unless you are one of those people I mentioned who like the look of a neat cut-out area around each sprinkler head, or you just want to be able to see all your sprinklers all the time.) A properly designed sprinkler system should be able to take a direct strike on a sprinkler head by a heavy mower without any damage. Properly selected sprinkler heads should also utilize pop-up risers that allow the nozzle to rise well above the grass level so that grass does not interfere with the water spray pattern. Almost all sprinkler bodies now are constructed of high-impact plastic, engineered in a way that, when properly installed, can take the shock of being hit by a large rider mower wheel without damage. However for this to occur the sprinkler must be installed on the proper type of riser that allows them to both absorb the shock and stay in an upright position. This website has suggestions for identifying both quality sprinkler heads and the proper risers to use. Unfortunately switching over a older sprinkler system to utilize new sprinkler heads and risers can be time consuming and expensive. The Sprinkler Buddy is a good temporary fix for these older systems that will reduce maintenance time and costs until such time as a proper repair may be made. A wise approach would be to use the maintenance cost savings created by the Sprinkler Buddy, and save back that money to fund a future replacement of the sprinkler heads and risers.
Q. How far should the sprinkler line be from a wooden fence? Im gonna run lines next to a wooden fence all around the perimeter of my backyard. Fence is about 8 feet tall.
A. There are several issues here that come to mind. Most of this applies to walls as well as fences.
If your are using a trencher or [plow to install pipe the machine will likely not get closer than 18 inches to the fence. I would stay even further away, maybe as much as 3 feet. Both of these machines have a tendency to slip from side-to-side or get out of alignment when operated, especially by a inexperienced non-pro. You don’t want the machine to go through the fence.
One issue here is future maintenance should you need to dig up the pipe for a repair. You want enough room that you aren’t whacking the shovel handle (or your shoulders) against the fence if you need to dig. That would mean at least a foot of distance from the fence. Maintenance of the fence is another issue. If you spray water on the fence it will shorten the life of the fence, not to mention leaving ugly water stains on it. It is near impossible to remove water stains from a fence.
Sprinkler Heads and Water Stains on the Fence:
The sprinkler heads should probably be about a foot minimum from the fence. The closer they are, the more water they will get onto the fence. The water will
stain the fence and also shorten the fence life. To keep the water off the fence completely means the sprinklers have to be very far from the fence, typically at a minimum 24″ away for spray type, 36″ for the larger radius rotors. There are variables that impact that distance they need to be away from the fence. Different sprinklers have different amounts of accuracy as to the edge of the water pattern. Impact type rotors often spray a lot of water to the side, outside the normal watered area, thus they need to be very far away. In fact, with impacts I would say that you are not going to keep the fence from getting wet, period (unless you keep the head farther away than the radius of the impact sprinkler!) Also wind plays a huge factor in blowing water onto the fence.
Don’t Plant Lawn Next to a Fence!
When I want to keep a fence dry I plant a minimum 3 foot wide strip along the fence with shrubs and water them with drip irrigation (or use shrubs that don’t require irrigation). That way I can keep sprinkler watered lawn at least 3 feet from the fence so the sprinklers are at least 3 feet away. If the area is windy I go with 5 feet distance.
Generally it is considered bad landscape design to put a lawn next to a fence, unless it is an extremely attractive fence that you want to be a focal point of the landscape! Standard practice is to “buffer” the appearance of the fence with a shrub planter along the base of the fence.
PVC fittings only come in 90 degree and 45 degree angles. Sometimes you need a smaller bend. A website reader asked if it is safe to bend PVC pipe and if so, how much can PVC pipe be bend without damaging the pipe?
The answer is that, yes, it is OK to bend PVC pipe, but don’t bend it too sharp or too much. Each pipe manufacturer has rules on what degree curve you can bend the pipe to based on the type and size of pipe. You could look that up but it would take a lot of time and even then figuring out how much a 15% bend is out in the yard is not very practical for the average homeowner. So here is a simpler “rule of thumb” that I basically just made up. But it seems to work reasonably well, it’s easy to do, and it gives you a nice, visual answer!
To determine how much is the maximum bend you should allow grab one end of a length of the pipe you plan to bend and hold it so the other end is off the ground. The amount the pipe bends on it’s own is about the maximum amount of bend you should allow.
You can also make any angle you want simply by using two 45 degree ells. This is easier to demonstrate than to explain. Get two 45 degree PVC ells. Lightly push them together onto either end of a very short piece of pipe. (Don’t glue them for now, this is just a learning experience. If you do ever use them on a irrigation system then you can glue them!) Now start twisting them in different directions. You will see that you can make any angle curve from 0 degree up to 90 degree! Add another 45 degree ell and you can make even more angles. Have fun. It’s cool!
Q. We typically have hot summers (month long +100 degree weather,) but recently we are also experiencing very cold winters (recently had 0 degree with -17 degree wind chills that froze a lot of pipes in the city.) Do you have any suggestions that would be useful about winterization for Southwest USA irrigation, or any particular materials that are specific to this area I should ask for?
A. This is a situation which occurs all through the southern US, as far inland as Nevada (Reno sees this type of temperature extremes every year), and up the west coast all the way into the Pacific Northwest. In these areas you see overnight freezing, which is typically followed by above freezing daytime temps. To make it worse, it is often necessary in these areas to irrigate during the winter months due to drying wind and high daytime temperatures! In these places we generally don’t winterize irrigation systems by draining the pipes in the winter, as the soil insulates them enough to prevent freezing. Sometimes we bury pipes much deeper in these places, say 18″, to keep them below the frost level. Any above ground equipment will need insulation installed on it to prevent freezing during the nights. So generally I wrap the above ground pipes with foam or fiberglass insulation, extending down underground to below the typical freezing depth. Where exposed to sunlight I wrap the insulation with a high grade pipe wrap tape that is UV resistant, or with metallic tape. Without protection foam insulation degrades pretty fast from sunlight exposure. Do not use standard duct tape, it is not UV resistant and will be a mess within a year or two. For above ground valves and backflow preventers you can purchase insulating covers that can be placed over them like a big bag, (one brand name that comes to mind is Polar Parka) or you can wrap them in fiberglass pipe insulation wrap. Just make sure water can drain out of the bottom someplace, in case there is a leak. Fiberglass insulation must be wrapped with plastic tape or something else waterproof to keep it dry, it will not insulate if it becomes wet. You can also put thermostat controlled electric pipe heaters on the pipes as another option.
The killer problem is when you have hard freezes that last for several days. Insulation doesn’t work very well during long duration freezes, as the cold has time to penetrate the insulation. In areas where freezing weather lasts longer than over-night, but you still need to keep the irrigation system operational, it is a good idea to install electric pipe heaters on backflow preventers and above-ground valves. If you don’t need to irrigate during the winter in hard freeze areas, then you should do a full winterization process that includes draining water from the pipes. For more details on winterization see the Irrigation System Winterization Tutorial.
Q: The pressure is blowing off the pipes/tubes from the barbed fittings on my drip irrigation system. This is only happening on hot days (30°C=86°F in the shade). Pipe temperature could be as high as 45°C=113°F. Our water pressure varies between 2.5 and 3.1 bar (35 and 45 PSI.)
A: Drip tube should not blow off the barbs, even on a hot day when the temperature softens the plastic tubing (however the heat does make it easier for them to blow off!) There are three common reasons the tubes blow off.
1. The most common problem is that the water pressure is too high. This is probably your problem. The water pressure should be around 1.3 to 2.0 bars (20 – 30 PSI). You should install a pressure reducer after your valve to lower the pressure.
2. The pipe and fittings may not be the same size. This is one of the pitfalls I warn about in my Drip Guidelines. 16mm and 18mm tube are both commonly referred to as 1/2 inch in the USA! The fittings for these two are not interchangeable.
3. Pressure spikes can pass through the less expensive pressure reducers often sold for drip systems. If you have high water pressure this may be the problem. The solution is to install a high quality brass pressure reducer valves. These generally are sold in the plumbing department rather than the irrigation department of stores and cost $50.00 or more.
Q: Have you come across tools to insert drippers in tubes or pipes? Pushing the dripper’s into the tube is leaving my fingers bruised.
A: You’re right, some of the hole punches are better than others. I have one that has a nice big grip handle on it that is easy to hold. But another inexpensive hole punch I have simply has a rounded top that you press with your palm to force the punch into the tube. It makes your palm sore after just a few uses. Pressing the emitters into the holes can be a pain too. Inserting a couple dozen emitters into the holes can leave your finger tips hurting! Some emitters have irregular, rough, or sharp edges that make it even worse.
Fortunately there are many tools made to help you out.
There are any number of simple hole punches. Some are small and hard to hold, some have larger handles which makes them a bit easier. All of these are very simple tools, you hold them in your hand and press a sharp tip through the wall of the tubing, a bit like an ice pick would work. Actually an ice pick would work to make a hole, however I have found that any type of pointed punch tends to be too aggressive; it punches a hole through one side of the tube and out the other, making two holes! Then you have to put a goof plug in one of them to plug it up.
Another thing to consider is the shape of the hole punched. Most punches actually create a round hole about an 1/8″ in diameter. Some create holes as large as 1/4″ for specific brands of emitters with larger barbs. It is much easier to get the emitter into a round hole than one made with a pointed tip, such as a nail. When holes are made with a pointed tip the plastic tube tends to stretch as the tip goes through it. Then the hole closes back up when you pull the tool out, the resulting small hole is hard to get the emitter barb into. Also a pointed tip is more likely to tear the tubing wall as the tubing stretches around the tool, creating something more similar to a slit than to a round hole. There is some debate as to if these tears in the tubing will enlarge over time (similar to how a tear in a plastic bag sill get larger if you pull on it.) I tend to think you are better off with a round tipped punch that punches an actual round hole in the tube, as opposed to a pointed tip.
Note that any punch that you hold with your finger tips, or press a small “knob” with your palm to operate, is going to be hard on your fingers or palm if you install more than a dozen emitters at a time. These super cheap punches work fine for a few emitters, but beyond that… ouch!
There are more sophisticated hole punch tools, like the Miracle Punch. It holds the tube firmly in place which aligns the hole properly. It operates similar to a pair of pliers, which is much easier on your hands. There is at least one other “pliers type” tool I have seen on the market, however it does not hold the tubing as firmly.
There are a number of devices made to install the emitters. Most of these are product specific, that is they only work with a particular brand and model of emitter. They generally have a handle on one end and a molded cradle that you place the emitter in on the other. You place the emitter in the cradle and then press it into a hole you have already punched in the tube using a hole punch. Some of these device have both the hole punch and emitter insertion cradle as part of the same tool.
Some companies, like Rainbird, make emitters that are “self punching”. The barb on the emitter is sharp enough to create it’s own hole when pressed hard against the tube. Rainbird makes a tool that you place the emitter in, then using the tool you press the emitter into the tube. My experience is that you need this tool to use the self-punching feature of the emitter. Without it I have not had much success getting the emitters lined up correctly and pressing them in with your fingers is near impossible. You don’t have to use the tool to insert the Rainbird emitters, it works fine to punch a hole first using a punch and then stick them into the hole.
TIP: Try wearing heavy leather gloves when installing the emitters to reduce hand pain. Also try putting a couple of pieces of cardboard in your palm between the hole punch and your hand, to help distribute the pressure over a larger area of your palm.