How To Install an Underground Sprinkler System on a Budget

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.

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!

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

Could you expand a bit on the filter drain installation?

Do they go on a "T-type" connector?

Thanks!

Norman

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

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?

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?

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.

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

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.

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

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.

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.