If you want be sure to get rid of this question, you may read this information and probably some Fairphone forum threads.
Why does my Fairphone 2 not come rooted by default? Do you provide a separate rooting solution for Fairphone OS?
We always try to find the best compromise for different users. Enabling root access by default poses a security risk for less advanced users. So we decided against it. It is also a requirement of third parties whose software we ship with the phone.
The Fairphone Open OS is an official alternative with root access available
This operating system is built from the open source code released by Fairphone via code.fairphone.com. It only contains open source software with the exception of the proprietary drivers you will need to properly run the hardware. The operating system is based on the Android Open Source Project (often referred to as AOSP) so it does not include the Google Mobile Services.
This operating system enables you to activate root access through the Developer options.
Hope this can help, but I'm sure that other people here have already installed UT on FP2. Someone could have more relevant information ...