Lean-to pergola 6x3 rafters

[phil21_06]

Hi. Looking for guidance on rafters. Im building a lean-to pergola under original house roof. I have a run of 4m and want to do a 5deg pitch. I have 2 6x6 posts and and going to come off a 6x2 on the wall of house. Just wondering will a 6x3 be OK for such a long run? I think 6x3 will look better then 6x2 against the 6x6 posts. Advice much appreciated. Thanks

 

[AJR75]

Assume you're meaning in timber rather than steel? A design from a structural engineer won't break the bank and will give you peace of mind in your construction.

 

[Forever Fendt]

Definitely need C24 , how about 2 pieces of 6x2 bolted together with a strip of 130 x6 flat in the middle won’t sag then