Installing an irrigation system in an established yard means hundreds of meters of pipe to bury without damaging the lawn, the paver driveway, or the flower beds. Digging by hand is slow and leaves a wide strip to backfill; an excavator cuts a trench that is too wide, is heavy on the turf, and won't fit through the gate. The trencher was built exactly for this kind of cut: narrow, deep enough, clean, and long.
How it works
A bar fitted with a toothed chain rotates like a chainsaw blade set vertically; the machine moves forward slowly, in reverse, and the chain cuts a channel exactly as wide as the chain itself, carrying the soil out and depositing it to one side in a neat windrow. The pipe goes in, the soil alongside is raked back over, and the lawn closes up within a few days. Depth is adjusted by lowering or raising the bar: for irrigation pipes you need to stay below the frost depth for the area and below the reach of a lawn aerator.
Where it pays off and where it doesn't
It pays off on long, straight runs through topsoil, sandy soil, or clay: the typical residential yard, a sports field, a park. It pays off wherever the result needs to be invisible after a week. It does not pay off in soil with large rocks, which jam the chain and wear down the teeth, or where the route involves tight curves around plants: in those sections you work by hand, with a spade on the bends. And it does not replace an excavator when the trench needs to be wide, for a basin or a sump.
Dedicated trencher or attachment on a multi-purpose machine
A dedicated trencher — a machine that does only that — makes sense for contractors who trench every day. For the landscaping crew that trenches ten days a year and hauls material for the other two hundred, a trencher as an attachment on a tracked multi-purpose machine is the other route: the same undercarriage that cuts the trench carries away the excess soil with the skip, brings in gravel for drainage, and the next day mounts a tiller or forks. One limitation: a plate-mounted trencher is capped at the depth of its model, and for very deep trenches a dedicated machine is needed.
In the Cormidi lineup
The trencher mounts on the attachment plate of the CMF multi-purpose machines and the mini skid loader, with depths up to 80 cm; on the C85 with quick-attach coupling, a version up to 68 cm is available. The tracked undercarriage fits through a pedestrian gate and leaves no marks on the lawn: that is why this attachment, on a tracked dumper, makes sense.
Before you start
Check with a spade, at three points along the route, what is under the lawn: soil, rocks, roots, old pipes. Set the depth based on frost level and the equipment that will run over it. Mark the route on the ground and keep the curves wide. And measure the clearance through the gate to the yard with the attachment mounted. The dealer can let you try the trencher on your own ground, before any other decision is made.
