View Full Version : ? for the Irrigation experts
The Slop Nazi
03-14-2006, 12:36 PM
I recently had an irrigation system professionally installed at my home (about 4-months ago). Can't wait to use it this Spring & Summer. I have a general question for the professionals on this board: Is it normal for trenches to "cave in" shortly after a new installation (within 2-3 months)? The company that installed our sprinkler system is coming out to repair the trenches, but I wanted some insight as to how often this occurs.
Thanks in advance for your feedback.
03-14-2006, 01:44 PM
Some settling may occur. That is the main reason we plow pipe in this area. A few weeks later, you can't tell where the lines are.
03-14-2006, 01:48 PM
Soulden't occur at all if the trenches were properly backfilled..you might get alittle but ut shouldent re-occur at all after they do it again
03-14-2006, 02:35 PM
Trenches ...?:confused: Ithought everyone used a vibraplow or similar equipment. My yard looked like it had never been touched after a week.
The Slop Nazi
03-14-2006, 07:04 PM
Yeah, they started in November, which is the beginning of our dormant season (bermudagrass), so the trenches are still noticeable. What I don't want, is to have trenches caving in during growing season (when you can't see the trench), and having someone sprain/break an ankle in the yard.
03-14-2006, 09:29 PM
We trench or plow depending on the soil type and circumstances. When we do trench, we hand tamp everything as we backfill to make sure settling does not happen.
I would run your sprinkler system long and hard and get everything really wet, this will cause the trenches to sink, after they are repaired, they probably won't sink anymore.
03-14-2006, 10:14 PM
The piss poor clay soil we have in this area is terrible about settling after backfilling. Once trenched, the soil dries and basically turns into adobe bricks. Even after re-wetting the soil before backfilling, and trying to compact the soil, it still will settling during the next few weeks. Dirt around here just sucks....
03-14-2006, 11:31 PM
If trenches are not water jetted or properly packed then settling WILL occur. :nono:
03-14-2006, 11:54 PM
Settling will occur. It not necessarily the sign of a bad contractor. If I do systems in the early spring (before our irrigation is operational) I usually compact the trenches as best I can and then figure on a return trip (if needed) to refill. It may be a good idea to leave a little extra in the line of the trench so that there is fill for the sinking.
03-15-2006, 10:08 AM
With bermudagrass, I typically add sand to the covered trench or divet as a topdressing to level it out.. The bermudagrass will grow right through it and you'll never know what happened once the grass starts to grow..
Just don't place the sand over your irrigation heads.
03-16-2006, 08:17 AM
Settling will occur. It not necessarily the sign of a bad contractor.
Settling for us usually occurs most with trenches where 1" pipe or smaller has been installed and the surrounding area is extremely grassy or weedy and we can't extract as much of the trenched dirt back into the trenches. This would be a good pipe size to plow if only for the settling factor and loss of dirt for backfilling. We always have extra dirt on trenches where larger sized pipe has been installed. We'll pack these trenches real well and then save the extra dirt in strategically located mounds to be transferred to trenches with smaller pipe sizes.
What I DO see bad contractors do is rake the dirt back into the trench and lightly tamp it intially so it looks like there is adequate backfilling. You just know there will be major settling in the future.
If I do systems in the early spring (before our irrigation is operational) I usually compact the trenches as best I can and then figure on a return trip (if needed) to refill. It may be a good idea to leave a little extra in the line of the trench so that there is fill for the sinking.
We'll do this and then fire the completed zones a couple of times each day to get moisture into the trenches. This helps in the settling and compaction of the trenches we've already finished. Our advantage is that we generally work on larger areas and then will have the groundsworkers come in with extra dirt and equipment to put the finishing touches on everything. They'll also usually overseed which gets the area up and running at a quicker pace.
03-17-2006, 11:53 PM
Your answer in short, is yes it is a common occurence around here. Your company is doing the right thing and repairing, everybody does it different and some will try to save a few bucks and labor time is the easiest way to cut the costs. It would not do anything to the integrity of your system, unless it was rocky or that you may need to raise up settled valve boxes.
03-18-2006, 11:17 PM
I found that the wide turf tires and weight of my Walker mower does a nice job of running along and compacting trenches.
A fairly new landscape and irrigation system that I worked on was originally installed by a cookie cutter company where the trench ruts were so bad it was a liability situation ready to happen. And, since mowers would drop down into the ruts and scalp the lawn, cutting grass less than 3” was risky. The owners had enough of this crappola and had the company come out and fix the mess, but that included having to pull up a whole lot of sod. Just goes to show that it’s best to have foresight rather than hindsight. Right?
03-18-2006, 11:22 PM
I can't say that any trenches I have backfilled have sunk.Period.If you compact it in under the pipe and hose jet it like purp says..and I do and fill,pack and wet ,fill, pack and wet and then when you get to the top of the trench you overfill and pack again there should not be any settling.
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