These two jobs have nothing in common except the shape of the hole. Both dig in a continuous line, and in both cases that line runs exactly where an irrigation installer chose to put pipe — round the perimeter of the slab, or straight along the property boundary. That is not bad luck; both trades and the irrigator were all working to the same logic about where things go.
Underpinning a slab in this region means excavating a series of pits round the outside of the house, most often within a few feet of the wall, and sometimes tunnelling in from the edge. The strip of ground that gets dug is the same strip that carries the foundation beds — and the foundation beds are where a system puts its shrub heads, its bed laterals, and very often the run that feeds round to the back yard.
There is a second effect specific to this trade and it lasts longer than the first. Foundation work deliberately changes what the soil under and beside the house is doing. Pits are excavated and backfilled, moisture regimes change, and the ground near the slab moves as it re-equilibrates over the following months. Heads that were set flush end up proud or sunken, rigid risers that survived the excavation shear later, and a bed lateral that was fine in March starts weeping in July.
So the honest advice is to check the system twice: once when the crew leaves, and once at the end of the following season. The second check is the one that catches what the first cannot, and it is almost never booked, because by then nobody connects a weeping bed lateral in July with an excavation that finished in March.
Irrigation designers run lines along boundaries because that is where the perimeter heads are and because it is the shortest route between the front and back of a property. Fence contractors dig along boundaries for the obvious reason. A powered auger down two or three feet on eight-foot centers, in a line, through unmarked ground, will find pipe if pipe is there.
The whole-system failure after a fence job is disproportionately common, and the reason is that the wire bundle runs the same route as the pipe. A zone wire takes out one zone. The shared common takes out everything, and does so silently — the controller keeps running its programme perfectly, energising nothing.
A fence replacement after a wind event is the worst version, because the posts frequently go back in near the old holes rather than in them — new ground, on the same line, with a system that has been in place for years.
On foundation work particularly, the ground gets backfilled, settles, and gets topped up. Repairing a lateral before that has finished means repairing it again. The exception, as always, is a mainline break — close the isolation valve and the wait is free.
Not just the zones anyone thinks are affected. A cut lateral shows up on the zone that feeds it; a cut common shows up as everything. Ten minutes with the controller and a notepad turns an argument into a list.
Wire faults are cheaper to find while the ground is still disturbed and the trench line still visible, and the splice needs a direct-burial connector inside a valve box rather than a twist cap in open soil. Pipe repairs are ordinary work and can follow.
Yes, and it is the one preventive step that costs nothing. Close the irrigation isolation valve for the duration. It will not stop anything being cut, but it means a severed mainline does not run at street pressure into an open excavation next to the slab — which is a materially worse outcome than a dry cut, both for the water bill and for the work being done.
It is worth the twenty minutes. Run each zone, flag every head, flag the valve boxes, and mark a best guess at the runs between them. It is not a survey and it will not catch everything, but a crew that can see flags along the fence line will dig differently from one that cannot. Utility locating does not cover private irrigation, so this is the only marking that will happen.
For a wire fault, occasionally — a partially cut conductor can make and break contact as soil moisture changes, which produces an intermittent zone that works after rain and not in a dry spell. That is not a system that healed; it is a fault that will become permanent, and it is worth finding while the trench is still identifiable.
It is a consequence rather than damage, and it is expected. Backfilled ground settles for months. Resetting those heads to grade on flexible swing joints, rather than rigid risers, is the repair that survives the next round of movement — and there will be a next round, because that is what this soil does.
Swing joints, and why rigid risers keep failing in this soil.
Telling a cut wire from a failed valve without digging.
What a proper splice looks like, and where it should live.
The 811 gap, and the half-hour before work starts.
A whole system down after a fence job is almost always one wire. Say what was dug and what the controller does now, plus where in the metro the property is.
Call (346) 605-8787 Describe the Problem
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