Timber for lean to roof

[Anish Mackan]

Hi All,
im looking to build a lean to roof on the side of my property.
the length along the wall is 7.5 meters and the projection is 1.8m
the lean to will be supported on the wall and on the opposite side by 4"x4" posts.
the roof would be 10mm polycarb sheets.
my question is what size timber do i use for the rafters and the ledger and header boards.
thanks in advance.

Mack

 

[Notch7]

4 x 2 would be typical for up to 2m span, but given the lightweight poly, maybe 3 x 2 would be ok.

 

[Anish Mackan]

Thanks for the update.
what about the size of wood required for the section attached to the wall (Wall Plate), i.e the section of wood that i will attach to the wall and for the section that the rafters will sit on? i was thinking 6" x 2" would this be sufficient?

 

[Leofric]

100 x 50mm ok for timber bearer fixed to wall.