Roof trusses?

[Joukko]

I'm going to expand the boiler room and also change the roof from flat to gable roof, I think it's called.
What size timber should I use for the rafters? I will make 5 of them myself. Boiler room + utility entrance and a bit of overhang, so it will be about 6.5m. I don't know yet what the pitch of the roof will be. I will then have tongue and groove boards, roofing felt, battens and counter battens, and then concrete tiles on top.

Jocke

 

[andersmc]

It is impossible to give a correct answer. Significantly more information is required to even calculate the trusses.

 

[b8q]

Hello!
The Träguiden provides a lot of tables and construction examples:
http://www.traguiden.se/TGtemplates/PageTwoColumn.aspx?id=1465