Lawn Irrigation Questions.

[My Dream]

Next year’s project is to install underground sprinkler system. I want to go with Rainbird although Hunter is a close second and I'll assume you can interchange systems. Rainbird used to have a free design service but last I checked it's now around $50.00. Since I'm located in Canada, nobody here offers free service and I was going to purchase everything online as this seems to be the time to purchase based on off season.

I have a problem since the Rainbird Irrigation Design Manual is over 100 pages long and gets really technical. Yes I understand about timers bring electricity to the valves to turn them on and off to each zone. Keep the sprayers the same model on each zone and make sure the spray pattern overlap and don't go over on the gpm for each zone. The manual makes it more complicated and somewhat confusing since I never did well in physics. How complicated can it be.

Anyone done this before and can give me pointers.

 

[eytonxav]

Can't offer much as to installing a complete system, but in my experience, Hunter components stand up better than Rainbird's.

 

[KingB]

Thanks for the heads-up on the availability of the design guide.

http://www.rainbird.com/documents/turf/IrrigationDesignManual.pdf

 

[My Dream]

Not sure why the Rainbird Manual needs to be around 140 pages, but can you read through it and give me the condensed version...........just keeeding!

I won't make it through the manual by year end, by then the sale will be over.


Bueller........anyone?


EDIT:

I maybe mistaken I think the charge is only for Texas and Canada, I could be mistaken and is only in email format.

 

[kumquat]

It's not really that hard.

First, decide what you want:

1. Basic system for grass.
2. Grass plus timers.
3. Grass plus timers + ground moisture sensors.
4. Grass plus timers + ground moisture sensors + flower beds.

It goes on and on. 1) and 2) are fairly simple, just divide your lawn area into grids covered by the sprinkler heads and install them & the timers.

I have no opinion on the manufacturers except that you can mix the sprinkler heads on a pipe. Don't recommend it but I have a mix of Dykes (NLS) and Rainbirt. As the Dykes fail, they get replaced with Rainbird.

 

[My Dream]

Thanks for the reply Kumquat;

Untill I read your post I didn't realize there were "soil moisture sensors". The rainbird Part Number: SMRT-Y sells for just over $100.00 but I think I'll forgo that for now.

My plan is to have grass + timer + flower beds.

In doing more reading I guess it boils down to;

Tap into your main supply line.
Install a shut off valve.
Code specifies a pressure reducing valve in my area
Another valve so that I can use a compressor to blow out the stagnant water before winter.
1 Valve per zone, I just have to figure out which one since there are several options for valves.
Run lines for each zone, have to figure out what size I need.
Install X amount of sprinkler heads per zone.
Intall a timer to control the valves and wire to the valve.


I guess that's it in a nut shell?

 

[JOHNNIE36]

I learned this from a sod expert some years back. His instructions are for Florida where watering sod can be a challenge. Spread out a bunch of thin tin cans (like those used for cat food) within a zone of your irrigation system and run that zone on "test" for 15 minutes. Check the amount of water in the can and adjust the timer accordingly to achieve the following results: one inch of water will soak six inches down into the soil. That is what you want your system to do. The average lawn needs one inch of water per week. The sod roots will go down after the water and the deeper they go the better off your lawn will be. Deep roots is the answer. So when you water your lawn, water to get one inch. Folks that water often are only promoting shallow roots and the lawn will develope fungus.

 

[ronocnikral]

this is a much better guide than rainbird or orbit or whomever.

Irrigation Tutorials Homepage and Main Index

I didn't bother drawing out my yard to scale, but rather tied a string to a piece of PVC and went out in the yard and figured out where everything would spray. I also didn't bother with all the calculations. I estimated about what it would be and then added more sprinklers until I reached diminishing returns.

I hand dug all my trenches, but in hindsight I could have gone out with spray paint and marked where I wanted the trenches and paid a guy $150 to come out and trench the entire yard. I still have some more to do so I definitely be using this service. Most people in my area rent a trencher, fight with it for a day and have to pick up/drop off. And end up paying about the same.

Moisture sensors are a waste IMO. I live in a very dry state and only water twice a week. Despite water being in scarce most years, most people water every day or those really interested in water conservation, every other day. I watch the soil and when it needs water, I water deep. My city in the interest of "spreading out the costs" rather than conservation imposes a minimum water charge, which, even with watering a lawn, we have never gone over. All my neighbors complain about their water bills in the $100's, but we have never gone of the minimum charge. They also admire my lawn. The point in all this rambling is how you water is just as important.

The most important is the zones. If you have flower beds, I'd suggest a zone just as a drip system. If you have the yard all up anyway, it isn't that much work and saves a lot of water. Plus, it helps, at least where I live, to keep the weeds down (just watering where the plant is, not the entire bed).

Good luck.

I used poly pipe and just shut off the water supply. I don't blow out the residual water.

 

[Original Wally]

My Dream....

1) Yes, tap into a pressure line and install a shut off - then you can continue to work on system and still have pressure in the house.

2). Designing circuits - I did our back yard ABOVE ground first. Got everything situated & coverage I wanted, THEN buried the whole system.

3) Do EVERYTHING in at least 3/4" pipe.

4) IF POSSIBLE, do a pressurized Loop.... rather than a bunch of branches off a main line. You end up with CONSISTENT coverage.

5) I am in central California... so I will defer to all you folks who deal with REAL cold about winterizing and frost protection of valves and what-not.

6) Get a timer with MORE circuits than you need. You WILL add more in the future.

PM me if you have any other questions.

 

[Ronstar]

Looks like you're getting some good advice here. I installed my system using the lake behind my house as a water source. So your system will be a little different than mine.

1. Yes - tap in and install shut off valve.

2. Then install a tee fitting that can be capped /uncapped to attach an air compressor to for blowing out the lines. Then install your pressure relief valve. This will prevent damage to your system from excessive water pressure or air pressure when blowing out your lines. (I use a small portable air compressor at about 100 psi.)

3. Design your system. i made a measured drawing and drew the zones/ heads before I began installation. I can't remember exactly how I did it, but you can calculate your existing flow gpm of your system and then calculate how many heads per zone you can have based on the combined gpm of the heads. Recognize shady/sunny areas in your design, and try to have these on separate zones. I have one zone that goes through total sun and then under some trees. I can't get the sunny area watered enough without drenching the shaded area.

4. Centralize your valves. Pipe is cheap, so I would put all the valves in one location close to your house. This will minimize your chances of slicing a sprinkler valve wire when doing landscaping, etc.

5. Definitely find someone/something to dig the trenches. This will save a lot of time and effort. Get utility companies to mark where your phone/cable/gas/electric lines are so that you can miss them while trenching.

6. Definitely go with 1" pipe minimum. I have one long circuit of 3/4" that I get very little flow from.

7. I have Hunter and Rainbird heads. I have no brand preference, but I have had more problems with spray heads than with rotors. I did not mix spray/rotor heads on the same circuits.

8. Get a good timer/controller. (with more circuits than you need as described above) My system is 17 years old and I'll be going to my third controller in the spring. I have a 10 zone controller, but use only 6 zones. A couple of zones have burned out on the controller, and I fixed it by switching the valve wires to an unused zone. But I'm going to get one that works with my iPad.

9. Just run your pipe, attach your heads, install your valves and wiring, and fire it up.
I run mine sometimes 3 times a day up to 15 minutes per zone each zone each time. Its best to water it good for deep penetration for root growth. Then I may skip a day or two.

10. The only thing I do for frost protection is to blow out the lines. If you are in a cold area, just make sure that your design is such that there are no water filled lines outside of the house.

 

[My Dream]

one inch of water will soak six inches down into the soil. That is what you want your system to do.

Thanks for the info JOHNNIE, once everything is installed I'll keep that in mind.

I hand dug all my trenches, but in hindsight I could have gone out with spray paint and marked where I wanted the trenches and paid a guy $150 to come out and trench the entire yard.

Thanks for the link, I'll read it this week.
I prefer not to dig by hand but the walk behind trencher rental is $225.00 for 4 hrs in my area. I just can't imagine digging down oh maybe 12" so I may rent and dig for the landscape lighting at the same time.

3) Do EVERYTHING in at least 3/4" pipe.

4) IF POSSIBLE, do a pressurized Loop.... rather than a bunch of branches off a main line. You end up with CONSISTENT coverage.

Lots of great advice thanks.

I believe my main supply line is 3/4", therefore I don't know if there is any advantage to expand the runs to 1"?

As for the pressurized loop, I understand as I did a balanced manifold when I installed body sprays in the shower. Same principal, but I forgot it also applies here.

6. Definitely go with 1" pipe minimum. I have one long circuit of 3/4" that I get very little flow from.

7. I have Hunter and Rainbird heads. I have no brand preference, but I have had more problems with spray heads than with rotors. I did not mix spray/rotor heads on the same circuits.

Thanks for the great advice Ronstar, seems 1" is the way to go even though my supply is 3/4"?
I'll check into rotors over spray heads but I believe they're twice the price. Yes I know, pay me now or pay me later.

Thanks everyone.

 

[kyounge1956]

I used to be a Landscape Architect, but haven't practiced for nearly 30 years now. The one thing I remember about sprinkler systems which I don't think has been mentioned here is the backflow prevention device. I know when designing systems we always included one--it keeps potentially contaminated water from the lawn from getting into the drinking water system. It's been so long I don't remember exactly where in the system it goes, but that information is probably in the design manual. If it isn't, somebody where you buy the parts will be able to tell you. It may very well be required by code.

 

[audreyh1]

In my development they lay out soaker hoses under the grass before sodding. Spaced about 18 inches. It's great. No sprinklers! Little water loss to the air. Very even coverage. We're in a somewhat arid area with lots of heat and sunshine.

 

[Ronstar]

.....
Thanks for the great advice Ronstar, seems 1" is the way to go even though my supply is 3/4"?
I'll check into rotors over spray heads but I believe they're twice the price. Yes I know, pay me now or pay me later.

Thanks everyone.

If your supply line is 3/4", then you probably won't gain anything by going to 1". In my situation it did, but that was coming off of 2" trunk line.

 

[ronocnikral]

Here's the low voltage transformer we bought for our landscape lighting.

Wholesale Low Voltage Transformers | Low Voltage Outdoor Lighting Transformers

It's multi-tap and some other things I can't remember right now. But, I ended up taking the one I bought at Home Despot back. I love the timer and light sensor. My lights come on at dusk and turn off around 1am. Everyday, no switch to flip...

I'd check into how much it would cost to have someone trench your yard. It will take them 30-45 mins (assuming a pretty straight forward design) vs you doing it all day.

 

[ronocnikral]

If your supply line is 3/4", then you probably won't gain anything by going to 1". In my situation it did, but that was coming off of 2" trunk line.

I disagree. You'll benefit greatly by using 1", which I'd suggest you do unless you are constrained by flow rate.

The reason is, where you tap into your main line, there will be a pressure associated at that point. Going downstream into your irrigation system, you'll have to account for all pressure drops from that point forward. So, if you use 3/4", you'll have greater pressure drops through your irrigation system.

This isn't to say you can't get away with using 3/4", just that 1" will help with maintaining pressure throughout the system.

 

[Ronstar]

What you say makes sense due to friction loss, etc. I haven't seen where a system upsides as it goes farther from the source.

 

[ronocnikral]

I don't do lawn irrigation for a living, but in oil/gas wells, it is common practice to switch over to a larger diameter pipe in the upper part of the well.

 

[samclem]

- The valves should go in a real box with a top that can be removed (the idiot who installed the last system I worked on put them all over the place and buried them).
- If there's anything you might need to find again, take a picture (with a tape measure/yardstick showing distance from 2 reference objects above ground)
- If you're putting the pipes in places where you'll be digging/trenching later (near a garden or flowerbeds, around the foundation, at a natural place for a later walkway, etc) consider burying another sacrificial pipe a few inches above your sprinkler pipe to intercept the first shovel blade. And it's not a bad idea to bury some 3" wide yellow plastic warning tape a few inches above the pipe everywhere else (you can buy it at Lowes or HD, it's for marking dangerous areas at construction sites). It just takes a couple of minutes. If you really want to take things to the next level, bury some steel wire along the pipe so you can find it easily with a metal detector.
- The risers are the part of the installation that seem most prone to breakage (when a sprinkler head gets kicked or driven over, etc). Consider reinforcing them. A riser that breaks right at the sprinkler head is much easier to fix than one which breaks farther down or which cracks the main line.
As mentioned elsewhere, after the lawn is established, water deeply and infrequently to encourage deep root growth and discourage fungus, etc.

Good luck!

 

[kumquat]

- The valves should go in a real box with a top that can be removed (the idiot who installed the last system I worked on put them all over the place and buried them).

In the OP's part of the world, the valves should be part of the manifold where the water line exits the house, it will be above ground. Some people remove the entire manifold and take it inside for the winter. It's not a bad idea.

 

[samclem]

Another thing--if you get billed for your sewer use by the amount of water you use, see if your municipality will allow you to have a separate water meter for these sprinklers, and not charge you the sewage fee for the water they use (since this water isn't bound for the sewage treatment plant).

 

[My Dream]

The one thing I remember about sprinkler systems which I don't think has been mentioned here is the backflow prevention device.

I forgot to mention it and yes it's required.

If your supply line is 3/4", then you probably won't gain anything by going to 1". In my situation it did, but that was coming off of 2" trunk line.

Seems debatable so I'm still undecided on what size to go with.

Here's the low voltage transformer we bought for our landscape lighting. I'd check into how much it would cost to have someone trench your yard.

That's funny since I just got my order from them and am really happy with the quality. Order came to around $1000.00 and yes I should do both trenching at once. They want $225.00 for 4 hour walk behind trencher rental.

I disagree. You'll benefit greatly by using 1", which I'd suggest you do unless you are constrained by flow rate.

Interesting......thanks.

- The valves should go in a real box with a top that can be removed - If there's anything you might need to find again, take a picture - If you're putting the pipes in places where you'll be digging/trenching later consider burying another sacrificial pipe a few inches above your sprinkler pipe to intercept the first shovel blade. And it's not a bad idea to bury some 3" wide yellow plastic warning tape a few inches above the pipe everywhere else. The risers are the part of the installation that seem most prone to breakage. A riser that breaks right at the sprinkler head is much easier to fix than one which breaks farther down or which cracks the main line.

Thanks for the suggestions.

In the OP's part of the world, the valves should be part of the manifold where the water line exits the house, it will be above ground. Some people remove the entire manifold and take it inside for the winter. It's not a bad idea.

I don't think I'll bring it inside, although it's highly recomended that I blow out any water so it doesn't freeze the pipes during winter.

See if your municipality will allow you to have a separate water meter for these sprinklers, and not charge you the sewage fee for the water they use (since this water isn't bound for the sewage treatment plant).

It is billed together and they won't install a seperate meter but still a good suggestion.

Thanks everyone.

 

[Texas Proud]

Heck, I wonder what some people are watering....

Our system is 1/2 inch line and works just great...



One of the suggestions that I would give if your DW is into flowers is to have a separate system for the flower beds.... my wife insists that I run the sprinklers 3 times a week to keep her flowers alive.... this is not the best for the lawn and it pisses me off....

We have so many different flower beds, and I do not know where any of our system is located, I just live with what we have....

 

[ronocnikral]

Heck, I wonder what some people are watering....

Our system is 1/2 inch line and works just great...

There are a lot of variables - where you tap in to the main, avg pressure your main feeds you, size of yard, yard design, number of zones, type of sprinklers, controlling equipment, num sprinklers per zone etc etc. If someone, like me, is too lazy to calculate all this stuff (and I have fancy software for pipe flow calcs), you'd find the cost of your laziness to be anywhere from nothing (you need the bigger pipe diameter anyway) to the small difference in cost of the different pipe diameters. Availability of parts is another consideration, as the big box store I prefer (and is closest to me) has plenty of 1" fittings, but fewer 3/4" and even fewer 1/2" for the type of pipe I chose to run.

 

[MBAustin]

This is somewhat off-topic, but we had a plumber visit this week to replace 3 bad outdoor faucets (one stuck open which necessitated the plumber visit, the other two drippy). I followed him over to the water shut-off valve (since this is the first time we've needed to use it since moving into this house more than 2 years ago). He asked me if I had one of the tools to operate the shutoff and I said nope. He went on to say that he gives one ($12 at your favorite big box home improvement store) to all of his friends as a housewarming present. He tells them to hang it on their garage wall in a convenient place and shows them how to use it. Said that many friends have thanked him later.