Skip the underlay?

[Jockose]

I'm in the process of building an entrance roof that measures approximately 220x260 cm.
I plan to lay down raw boards and then roofing felt on top.
The question is, do I really need to use underlay felt, or is it sufficient to use only surface felt for a "simpler" entrance roof?

 

[ArneTW]

It is probably like everything else.

You will likely never miss the underlagspappen... until you do.

There is not a big saving in cutting corners.

/ATW