The first time I did some DIY retic I tried to install my kerbside sprinklers by digging along the line of the kerb.
After 10 minutes I had all but given up. You see the soil along the kerb is actually roadbase. It is hard and rocky and not easy digging. If you want to install sprinklers along the kerb then dig a trench one metre away from the kerb and parallel to it and then ‘t’ off to the point where you need sprinklers. You will still need to do some hard digging but it will save you a lot of effort and you will do the job right.
The other tip with kerbside sprinklers is to make sure they are well below kerb height – because they will get driven over. If you’re lucky they won’t get damaged, but if they are even sticking up a little bit then expect to replace them regularly.
I get calls from one client a few times each summer to replace the same sprinkler. Personally I reckon it would be easier just to sink the sprinkler a bit lower…