How is it to lay roofing felt yourself on a 30 m2 yard building with a 30-degree roof - it's supposed to be an uninsulated tractor garage - can't be that hard, right

?
I'm wondering because in the building permit application, you need to state what the roofing material will be, and I'm thinking that felt (on a base of some kind of wood board or similar) must be the cheapest and easiest, right?
Alternatively, would it be even easier to just kind of tar the base?
Edit: looking a bit at Icopal's website, it seems like it might be appropriate to use Micoral YAM 2000 underlay felt on top of the wooden roof base and then Icopal TopSafe 14 as the top layer...