Tenant DYI job on sprinkler system

[Constantia Petrou]

Hello,

I am the landlord for a single family home. Yard maintenance at the house we are renting out is the tenants' responsibility. They basically need to be watering the plants regularly. While we were away they decided to put in a sprinkler system to automate watering and make it easier for themselves to maintain the yard. Though they are supposed to ask before making any changes to the property they did not. I don't want to raise an issue over their not asking first, and I will let that slide to maintain a good relationship. Because they did a DYI job on sprinkler installation, I just want to ensure that the sprinklers are installed properly. The guy is in construction (project manager on large construction projects) and claims he is handy, having done work on the home he owns. We will be going over to the property for him to show us what he did. What should I watch out for to ensure a proper job was done that will not create problems now and in the future? (ie, I know to look for any leaks that could damage the house structure over time but any other details from the community would be greatly appreciated). Thank you