How deep do you need to dig sprinklers when installing them?
Its a common question and the simple answer is that they need to sit approx 10ml under the finished level of the turf. If you are using 2 inch sprinklers then its really important to get this right as there isn’t as much rise on the shaft. With 3 inch sprinklers they can sit a little lower and it not be a problem.
What you don’t want is a sprinkler that sits above the level of the turf as it then becomes a liability every time the lawn gets mowed.
As a general rule I dig to a depth of 150mm or the top of my work boot. Its also really important to make sure kerbside sprinklers sit well under the kerb level so that cars don’t break them when they drive on the verge.
Sprinkler Height – DIY Installations