Looking for lost/buried sprinklers

[Percival P. Cassidy]

We have been in our current house for almost two years now, and although it has a 4-zone sprinkler system, there are areas of lawn that do not receive adequate water.

A couple of days ago I happened to be outside while the sprinklers in one zone were operating and noticed a dribble of water from a pop-up I didn't know existed. Even when the water was on, the pop-up barely reached the level of the top of the grass.

Now I am wondering whether there are other sprinkler heads that got buried even further down than this one. The neighbors on both sides (no fences) have been there only a few months longer than us, so asking, "Did you ever a notice another sprinkler head anywhere around here?" achieves nothing.

We don't have a plan of the sprinkler system that would show where they were installed originally. Nor is there anything to indicate by whom they were installed, so we can't go back to the installer (if it wasn't in fact a DIY job) for information.

Any bright ideas for a means of locating buried sprinkler heads?

Perce

[nielloeb]

Hire a sprinkler company to blow air through the system as though they are draining it for the winter. Walk around listening for air coming out of the ground. Then again, if you hire a company to blow air, they surely can find and fix all the heads for you anyway.

[Percival P. Cassidy]

On 09/16/05 02:19 pm [e-mail] tossed the following ingredients into the ever-growing pot of cybersoup:

We didn't have the system air-blown last year, and no harm came to it. We did drain it, however.

Anyway, if an 80psi water supply can't open a buried pop-up sufficiently to produce a pool of water or a squishy patch in the lawn, do you think I'm going to hear anything from said pop-up by blowing air through the system?

I should mention that although the pop-up that just revealed its presence is in line with several others, it is not on the same line as those others. All of them are Teed into another line of pop-ups running parallel to them. What makes me think that there may be some more buried ones is that the gap between the one that just appeared an the next one in line with it is three times the spacing between many of the others; IOW, I am thinking that there may be two more buried pop-ups. And, yes, I have dug around where I think those "missing" pop-ups might be, but I haven't found anything.

Perce

[SteveB]

You might get someone with a metal detector to do it for $20. I once dropped one of those tiny mister nozzles. About half the size of a pea. It found it no problem. Yes, it will find the small amounts of metal in a plastic sprinkler.

Steve

[SteveB]

Metal detector. You may know someone who does this for a hobby, or call around to the local shops and maybe you can find someone.

The brass in sprinkler heads is VERY easy to find for a metal detector.

Steve

[BobK207]

How about turning on the system & throttling the manual valve WAY down, leave it running for a LONG & look for the telltale wet spots

cheers Bob

[Percival P. Cassidy]

On 09/16/05 03:07 pm SteveB tossed the following ingredients into the ever-growing pot of cybersoup:

That was one of the things that occurred to me early on, but we'd prefer a cheap solution -- but are there metal detectors as cheap as $20 that would work?

Although the pop-up that came to light most recently is a Nelson with a brass nozzle (and the riser is GI), most of the ones we know about are Rain-Bird or Toro, which are all-plastic except for the spring and a tiny flow-adjusting screw. Is a metal detector going to do much good with such sprinklers, especially if the risers are plastic as well, as most of them are. About the only metal other than the spring and the tiny adjusting screw would be the hose clamp(s) down in the ground.

Perce

[Tim Fischer]

U sure? sounds like the system isn't working properly...

Maybe. We had a sprinkler system at our old house, and in MN, you pretty much *have* to blow it out. When the company hooked up the compressed air, the sprinklers acted as if they were on "fast forward", going back and forth rapidly, instead of the gracefully they normally did. You may well find more heads that way. Since it's about the end of the season anyway, you could kill 2 birds with one stone.

-Tim

[Tim Fischer]

Not all sprinkler heads are brass. Most of the newer gear-driven ones are virtually all plastic, other than the lifter spring, which I don't think has enough mass to be found easilly.

-Tim

[Norminn]

clipped

How old is the home? Sprinkler installed at construction? If you check with your local code folks, there may be a permit for the installation and the contractor may have the plan. I'm an optimist :o) If a smaller town, the brand name of the components might be a clue for finding the installer in the yellow pages, if done by contractor. Our system has an old, old sticker on it.

One non-operating head may just be broken or plugged. Take it off and put on a new one....take care not to let dirt get into the line. Heads can be purchased without a spray head for the purpose of purging the line before you put on the spray head. Whilst you have your excavation open, trace the pipe by line of sight and look for heads covered by grass. Down here in FL, St. Augustine grass could easily grow over a head, or accumulated grass clippings also. Unless you have an oddly shaped lot, the heads should be pretty regularly spaced, so's you know where to look.

[Boots]

though they

air coming

can find and

We didn't have the system air-blown last year, and no harm came to it. We did drain it, however.

Anyway, if an 80psi water supply can't open a buried pop-up sufficiently to produce a pool of water or a squishy patch in the lawn, do you think I'm going to hear anything from said pop-up by blowing air through the system?

I should mention that although the pop-up that just revealed its presence is in line with several others, it is not on the same line as those others. All of them are Teed into another line of pop-ups running parallel to them. What makes me think that there may be some more buried ones is that the gap between the one that just appeared an the next one in line with it is three times the spacing between many of the others; IOW, I am thinking that there may be two more buried pop-ups. And, yes, I have dug around where I think those "missing" pop-ups might be, but I haven't found anything.

Perce

[SteveB]

I took the OP to say this was an old system with older parts .................

Steve

[oren]

Pehaps you can "cap-off" a few sprinklers on the zone, turn on the zone and see if they might pop up... Also look for signs of greener grass at or near the sprinklers.

Oren At this moment I do not have a personal relationship with a computer. Janet Reno, Attorney General 24 May 1998

[Percival P. Cassidy]

On 09/16/05 11:22 pm SteveB tossed the following ingredients into the ever-growing pot of cybersoup:

Even this one zone was a hodge-podge of Nelson pop-ups with brass nozzles and all-plastic Toro and Rain-Bird pop-ups.

Another zone was a mixture of Rain-Bird and Lego impact sprinklers when we moved in, but I have replaced the Legos by Rain-Birds. it's bad enough trying to balance a system when the sprinklers are all the same brand and model but are not all set for the same arc, without having to deal with different brands with differing patterns and flow rates.

Perce

[William Brown]

Since the head is only dribbling, I suspect there is some blockage. Either that or too many heads have been put in the same zone, and the pressure can only elevate the first ones.

I would dig up around the dribbling head, remove it, and see if water gushes when you turn on the system (be certain to take steps to keep dirt from getting into the lines. If the pressure is adequate, clean or replace the head. While you are doing that, you could look to see if this head is on the end of a line, or whether the line continues, which would give you an idea where to look for more heads. Analyzing the pattern of heads should also give you an idea where to look if you find an unwatered area.

I regularly lose heads, as my lawn grows over some during the non-watering season. While I do have a map, they are still hard to find. I run the system and look for the puddles that form around a blocked head, then probe with a thin screwdriver.

[Percival P. Cassidy]

I've already replaced the sprinkler that just came to light (and blown out the whole zone by turning on the water with all the "innards" removed from the cases), but I think the primary reason that I saw only a dribble was that it was pretty much buried.

This zone has 11(!) pop-ups (the little spray-nozzle kind, not impact sprinklers or gear-drive rotors). This may seem a lot, but the water pressure at the hose bibs is 80psi, so I don't see why it wouldn't be sufficient to run that many (Rain Bird gives radius and gallonage figures for this kind only up to 30psi).

As for the layout: this zone has one line with eight of these pop-ups, plus three others (that I have found so far), each on its own line that is Teed into that other line. These latter three are irregularly spaced, and this is what makes me wonder if there are one or more buried intermediate ones.

I agree with you about not needing to get the system blown out with air. The previous owners left us instructions for draining the system.

Perce

On 09/17/05 05:40 pm William Brown tossed the following ingredients into the ever-growing pot of cybersoup:

[William Brown]

Mine has a single line down the center, with each head on a smaller line that runs off the main line, left or right. If properly done (big IF, I know) every area should be covered by two heads, so if you have some areas that are not covered doubly, that might indicate where a dysfunctional head is.

I have about the same water pressure as you, but there is more than pressure involved. Your pressure through a half inch line will not drive as many heads as the same pressure through a 3/4 or larger line, and that includes the lines from the water main through the meter and your house.

I have 11 heads on my line (3/4 supply line in the basement) and the water supply/pressure is marginal. If someone flushes a toilet while my system is on, you can see the heads be affected, which is one reason its good to run them very early in the morning. My back yard system is very old, and they only had fixed angle heads when it was installed; seeking to perfect the system, I bought and installed some variable angle heads. Since the darned things are hard to read, I guessed that a 15 foot (I think) radius would be nice, but when I installed them the whole system looked anemic, and some of the far heads wouldn't even erect. I went back and got 12 foot (I think, I know this time I took one of the old ones to the supply house and had him read it) radius heads (not a problem, other than the embarrassment, as they are cheap) and the system's health was restored, so I think its a pretty complicated calculation as to whether your system has enough pressure and volume to drive that many heads.

Good luck > I've already replaced the sprinkler that just came to light (and blown