View Full Version : Help needed please.
02-26-2006, 01:47 PM
I am a first time home owner who does not anything about sprinkler systems. I contacted a few local irrigators to bid on a sprinkler system for my house. They have bid with different specifications that I am trying to understand so that I can decide which bid to go with. Any help with the following questions will help a lot.
1. Is it better to go with 4" or 6" spray heads? My quess is 6" would be more expensive. What would be the long term impact of either one?
2. How often will I have to raise the sprinkler heads? What effort doest that involve?
3. Some are offering 1 " main line pvc pipe and 3/4" lateral pipe while others are offering 3/4" main line pvc pipe and 1/2" lateral pipe. Obviously smalleri diameter pipes cost less but which ones are better? How much is the price difference. I may be saving a few bucks by going with smaller pipes but in the long run will they be right ones to use?
4. Some want to use Toro 570 spray heads and shrub sprays while others want to use Hunter sprays. Which are better? Similar situation with Conbraco vs Irritrol valve and Hunter Pro C controller vs Rainbird esp controller. Is there a place where I can get any comments about people's experience with these or reviews about these brands?
Thanks in advance for your help.
02-26-2006, 02:28 PM
Designing an underground sprinkle system requires a good knowledge of hydralics. It is not just a matter of running pipes and sticking sprinkers around. You have to consider the amount of water available, the distance it must be piped, the number of circuits that will be required, and the type of vegetation that is to be watered. You are going in the right direction by having this laid out be contractors, and I hesitate to second guess any of them based on what you have outlined, but I will say that unless the mainline is extremely short and the number of sprinklers to be run on the circuit is small, a 3/4 mainline with 1/2 laterals is a joke. Don't try to "save" a couple of bucks with small pipes. The expense of installing a system is not the materials. PVC is cheap. The expense is the labor, but it takes no more time to connect 1" pipe than 1/2" pipe. I'm not saying to just get large diameter pipe, get it designed by someone that has a record of satified customers. :)
02-26-2006, 03:54 PM
1. All of the brands and components you have mentioned are first quality. Some, especially Rainbird, have "homeowner" lines and commercial lines. But you would not be disappointed with either.
2. Speaking of disappointment, I would be disappointed with any contractor who has not given you a better explanation than you have shared here.
a) Either fixed spray heads like the Toro 570 or the Rainbird 1800 series; or gear driven rotaries like the Hunter; are capable of doing the proper job for you. With either type, what is important is the precipitation rate calculation. You must not mix types. The rotaries will cover a larger area with fewer heads, but may need longer run times depending on the nozzles selected.
b) Once the sprinkler type and nozzles are selected, THEN you can do GPM calculations and zone layouts. 1" pipe delivers about 4 times the flow of 1/2". You would never be hurt by pipe being a little large, but use too small and you will have trouble for the rest of your life!
c) If your contractor has not provided, or at least indicated that he will provide a detailed zone layout design drawing with GPM and pipe sizes calculated, you really should look for someone else. These diagrams and layouts are provided FREE to consumers and contractors by Toro, Rainbird, Orbit, and I assume by other brands.
Regarding pop-up length, 4" properly installed is adequate for a new installation, and is often chosen by homeowners to ease digging. A 4" Toro 570 needs the pipe to be at about 8½", and a 6" needs the pipe to be about 11". Over the years, heads settle, lawns seem to swell up, and it is not uncommon to end up with 4" heads not quite getting up over the grass. When necessary to fix it this can be done relatively easily using swing joints, so it is not necessary to actually dig up the whole pipe.
Installing 6" from the git-go will cost more up front, but may make the system usable for 20 years instead of 10 without major overhauls.
Rotaries will cost more than 570's by quite a bit, but may provide a more even precipitation pattern. I especially like the Rainbird "rain-curtain" but the others are very good as well.
3. Have they talked to you about backflow prevention and permits?
4. Have they mentioned proper overlap of the spray patterns?
02-26-2006, 09:04 PM
Ditto Jimbo's comments! I'd expand on one of his point just a tad. The swing joints referred to are lengths of flexable tubing that connect the sprinkler with the pipe. Besides being able to raise the sprinkler head with needed, they provide a soft connection so that you will not break the pipe by running over the head with a mower or even a car. They make setting the sprinkler at the desired level quite easy.
02-26-2006, 10:06 PM
Gary and Jimbo,
Thanks for the quick replies. All of them did talk about the backflow prevention and getting the permits and inspection done within the bid price.
My backyard is about 2000 sq. ft. The front and side yard on one side of the drive way is 2700 sq ft while the other is 1926 sq ft. This is the area coverd by bermuda grass and does not include the area where plants/shrubs are planted (not very large areas). It is a pie shaped lot with the wider side of the pie in the front.
I have attached a file that lists the number of Devices by each one of them. I have tried to link a layout below too. As you will see they are so widely different. That is why I am confused. Some of them have mentioned in the bid that they will cover 100 % of the area and shrub areas will be covered separately. None of them talked about nozzles proper overlay spray patterns, precipitation rates and GPM calculations except one (who's bid is the highest btw).Another one talked about going up to 12" depth digging in areas needed or the regulated depths.
You mention raising the heads once the by using swing joints once the lawn swells up. What exactly would one have to do ?
02-27-2006, 04:59 AM
Thanks for clearing out what these swing joints mean. Usually after how many years would I have to raise the height of the spray heads. My yard has bermuda grass and my house is a little less than 3 years old.
02-27-2006, 05:03 AM
I have a .jpg format layout of my yard (112 kb) but this forum does not allow uploading a file larger than 39 kb, otherwise it would have helped clear what I was saying in my earlier post. I hope the post with the attachment of the quotes is enough for you to give your expert opinion.
Thank you so much for helping.
02-27-2006, 05:30 AM
This is my own opinion:
I think it's important that your contractor bury the lines as deep as possible. Our's went 12" deep, and it made the subsequent installation of a patio and some landscaping a little easier; the mains didn't have to be sheathed or re-routed.
Personally, I don't think it's a big deal to raise heads. You will probably ever only have to move or raise a few of them. The heads screw off by hand, and they make all kinds of risers to go in between the pipe nipple and the head.
As with anything, you should read about it first so you don't do any damage, but it's not a hard operation.
02-27-2006, 06:48 AM
I am impressed with the 3 year warranty all have offered.
On the layout diagram, it should show that the spray from each head reaches to the next adjacent head, to fill in for low precipitation close in. i.e. if you are using heads with a 12" spray pattern, they must be about 12' apart, not 24'/
Using swing joints on all heads at initial install adds a slight cost, but the benefit of the soft arm, as Gary S. mentioned, is significant. One of the most common sprinkler repairs is snapped off risers caused by foot or lawn mower traffic. Also, there is a labor savings going in, because it is so much easier to set the depth and not be quite so critical with pipe depth in the trench.
It sounds like you have 3 good contractors here. Sort out some of the minor details to make sure you are apples to apples. Then, the usual factors of references and just your general "feel" about a guy will help decide.
We have hit you pretty heavy with everything we could think of. On the other hand, it is not rocket science. If all are using some kind of "calculator" to ensure that pipe is not undersized for the GPM demand, this should come out well for you.
02-28-2006, 05:02 AM
Thanks for your reply Jimbo. Two more questions.
It is recommended that if you are in a cold area then the trench should be dug up so that the plastic pipes in the trench are below the frost zone in the ground. I am in Austin, TX area where we get a few flurries every year with some cold days and freezing rain that may last 2/3 days each winter. We may get such cold days 3-4 times each winter. Do I need to make sure that the trenches are below the frost/freezing zone?
2. I have seen several homes in my subdivision that have sprinklers. The concern I have is too much water getting wasted in the small strip between sidewalk and the street. This strip of grass is 3.8 feet x 50 ft wide and I usually see over half the water sprayed in the area going in to the drains. Is there a way to reduce this wastage?
02-28-2006, 07:31 AM
1. Based on your description, it doesn't sound like your ground will freeze beyond one inch or so. In frost areas, one technique is to install auto-drain valves which go in at the low point and cause most of the water in a pipe line to drain out after each use.
JEEZ: deja-vu all over again: I am reminded of having to locate all the auto-drain valves on the Main Ballast Tank Blow system during submarine qualifications.
2. Watering those narrow parkway strips is the bane of landscapers. All the brands offer so-called "strip" nozzles which water something like a 4' by 15' or 4' by 30' strip. If you put the strips on a zone valve all by themselves so you can adjust the volume down, and keep the watering time short to minimize runoff, that is about the best you can do. Better to set up multiple watering times, water for just 3 or 4 minutes, repeat several times at 30 min to 1 hour intervals.
02-28-2006, 04:55 PM
Another question for you Jimbo. I have a 8' x 10' covered patio. Sometime down the road I might consider extending the concrete to one or both sides of the home. If there are spray heads that get installed now with the pipes what would be the impact? One alternative is to not install any pipes that go with a spray head in the area which might get covered with concrete some day. The problem is that if I never get that done then I will have to use a hose to water those areas.
03-01-2006, 07:51 PM
You can always remove or block off unused heads, or adjust spray pattern angles. You might consider not running any pipes under the area which will be concrete, except laterals to heads which would be eliminated anyway,
03-08-2006, 05:08 PM
if you're gonna pour concrete have them lay a PVC pipe or two in the gravel first. if you ever want to fix your sprinkler or run 110v out to your shed or something, just find the end of that pipe and you're in business
just keep a plan of your system so you know where everything is when you do other work.
i would definitely make sure those lines are deep enough. the pipe pulling machine does a pretty good job but the contractor wiill have some helpers digging trenches out to some of the corners you wanna make sure they're digging them deep enough you're not going to hit it with a lawn aerator or something.
for the narrow strips a contractor should have a good selection of misters. misters are just small sprinkler heads. instead of rotating they spray a circle of water. just select a head with a pre-determined radius. (90,180, 360). run 180's (half circles) up and down both sides of your strip but with a short fine spray that won't go wasted. long as you have lots of heads close enough together there will be enough overlap that the lawn gets what it needs but you're not using the large heads that will waste a lot of water..
i think the flexible tubing is over-rated so i wouldn't pay extra for them. it's nice if you've still got to grade and sod a half acre lot and will be adjusting 50 heads after. but if you just want to be able to raise a head now and again, it's not a problem. with an exacto, some cheap hose clamps, a few feet of hose and some couplings anyone can do this kind of maintenance.
03-16-2006, 05:02 AM
Can anyone please recommend what are the pros and cons of using Febco or Conbraco Backflow preventer. Different contractors are recommending different ones.
Also should the sprinkler system be designed at 15 GPM or 10 GPM. Right now the pressure is high and can handle 15 GPM. But in the next 10 yrs over 1000 homes are planned to be built in our area and I would think the pressure would drop. So if it were designed at 15 GPM the system may not work as good in the future or may be not at all. Any opinions?
03-16-2006, 05:21 AM
Any opinion on using rotators instead of rotors. Some contractors recommend using rotators because they have a more even precipitation rate than rotors.
03-16-2006, 06:27 AM
"Also should the sprinkler system be designed at 15 GPM or 10 GPM. Right now the pressure is high and can handle 15 GPM. But in the next 10 yrs over 1000 homes are planned to be built in our area and I would think the pressure would drop."
The system must be designed for both pressure and flow. The pressure at the heads determines both flow rate through the head and range/area of the pattern. Your sprinkler system contractor should know how he will deal with pressure variations.
If your area is served by water towers, your pressure shouldn't vary a lot if the distribution system is designed for the demand of 1000 new houses. Distribution systems are supposed to be able to deliver enough flow for fire suppression when there is high demand on the system.
03-16-2006, 08:03 AM
I would agree that rotors have a more even precip coverage. You still need to overlap for uniform coverage.