You've already decided where the sprinklers will go, you have the layout in hand and the pipes coiled in the garage. Now comes the part that's usually underestimated: cutting a narrow, continuous trench across the lawn, along the edges of the flower beds, maybe all the way to the back of the yard where the rows run. Doing it with a spade takes hours and disturbs the ground far more than it looks from the surface.
First step: marking the route
Before any digging, it's worth laying a string line or chalk on the ground to mark the exact path of the pipes. The route should follow the edges of the lawn and flower beds, not cut across them diagonally, for two practical reasons: the trench is easier to reopen if there's a fault, and you disturb less of the existing vegetation.
At this stage you also mark the areas to avoid: shallow roots from trees and shrubs, already-buried gas pipes or electrical cables, concrete curbs. Digging near a large root without seeing it means cutting it clean through, with damage that shows up months later.
The right depth for the pipes
Irrigation pipes need to be buried deep enough that they won't be cut by the first pass of a blade or tiller during routine yard maintenance. A sufficient depth is one that puts the pipe below the layer that normal surface work reaches, but not so far down that every future repair becomes a full jobsite operation.
A chain trencher cuts a narrow, vertical trench with clean walls. That's the advantage over manual digging: the volume of soil removed is small, the walls don't collapse, and the pipe can be laid without having to widen the bottom by hand.
How the chain trencher works
A chain trencher is a continuous-chain attachment with cutting teeth, similar in principle to a band saw oriented vertically. It moves slowly through the ground, opens the trench, and conveys the spoil to one side via an auger. It doesn't displace the soil on the sides, doesn't create uneven ground, and leaves a clean slot where the pipe can be laid.
It works well in compacted, clay-based, or fine-gravel soils. It meets its limit when it hits medium-sized rocks or large roots: in that case it stops and the obstacle needs to be worked around or removed by hand before continuing. On ground with a lot of rock the chain trencher slows down significantly and may not be the right choice: in that case you consider manual digging in sections or a pickaxe to remove the larger stones.
The chain trencher on a multi-purpose machine: how it fits into the workflow
Mounted on a tracked machine with an attachment plate, the chain trencher becomes part of a logical sequence: cut the trenches, lay the pipe, backfill. The tracks distribute the weight across the lawn and allow work even on wet ground or a slight slope without leaving deep ruts in the turf.
The operator walks alongside or follows from the platform, adjusting the travel speed based on how hard the ground is. On straight sections you advance continuously; on curves you raise the chain trencher slightly, turn the machine, and continue. At points where the route bends close to a wall or a curb, the machine's compact width lets you get into spaces where a larger machine wouldn't fit.
To understand how to mount and configure the chain trencher on a Cormidi machine, you'll find the details in the article Chain trencher for irrigation digging: how it works and which machine to mount it on.
In the Cormidi lineup
The CMF multi-purpose machines mount the chain trencher via the attachment plate in the SP2 and SP3 versions. The same machine, by switching the attachment, can carry a dozer blade to prepare the ground before digging or a sweeper to collect the spoil at the end. You don't need a dedicated machine: you work with a single undercarriage and swap the attachment on the jobsite.
Backfilling and restoring the lawn
After laying the pipe, the trench is backfilled with the same spoil, compacted in layers. If the lawn has been crossed, the turf recovers well when the trench is narrow and the walls are clean: a little fine soil on the surface, some seed, and a few waterings are enough. A wide trench with collapsed walls requires a much longer restoration job.
Before deciding which machine to use, measure the width of the access points you need to get through into the yard, check what type of ground you have, and mark where any already-buried utilities run. With that information in hand, your local dealer can point you to the configuration best suited to your work.
