Size of steel for lean to roof

[kapsopod]

Hi everyone,

I wonder if anyone might be able to offer some assistance with sizing some steel for me.

I want to build a lean to roof to cover an outside terraced area. The design is as follows

3.60m(this does not include any overhang) x 6.8m overall covered area
It will have 4 posts to take on the 6.8m size.

The roof will be covered in poly-carbonate sheets, so the structure will not have to take any big load, but I am concerned about the structure itself being strong enough to support its own weight without "bending" in the middle of it because of no vertical support there.

Would you be able to give me some idea of what pitch the roof needs to be and the dimensions of the wood(rafters, wall plate etc).

Thanks in advance for any help anyone can offer.

 

[noseall]

You will also need to counter 'racking', wind uplift and factor in snow loading.

 

[^woody^]

5x2 rafters