Should I install felt with crack lines?

[robert-sd]

Hi, I bought a shed that came with felt that needs to be installed. A couple of months have passed since I received it and the felt has been sitting in the garden flat. Finally got to installing the felt but I notice it has quite a number of crack lines and I was wondering if it's worth installing as is or if it's better to buy a new one (it's £30). My plan is install a green roof on top of it so I want something solid that lasts.
Any advice welcomed, thank you.

 

[foxhole]

https://www.permagard.co.uk/advice/green-roof-construction

 

[PeteJG]

Does it rip easily? Felt supplied with sheds is often cheap rubbish so if it does then whatever you're going to do, chuck it and get some decent stuff!