Make your own ridge beam

[SBH]

Don't understand why the glulam beam needs to be 8 m long? Outside the gables, it's not useful.

for some glulam beams are 8 meters. but then you can take it in the right measurements too.

 

[SBH]

have access to some free planks. I don't think I have enough spare timber. I can also get short pieces to make a truss for free. Glulam 90x400 should be enough, otherwise 90x450...it's snow zone 2.5.

I'm letting the wall plates extend as support for the rafters at the edges..

do not use scraps as construction timber. even if you glue and screw according to all the rules. buy ready beams. it benefits you in the long run.