Lean to roof - beam size for 6.5m span

[Ducko888]

Hi
I'm currently building an extension with a lean to.
The rafters will be spanning 3.3m at an angle of 18 degrees.
The high end of the rafters will sit on a beam spanning 6.5m. I intend to combine 8x2 s to form an 8x8. Fully pinned with coach bolts at 400mm centres. The roof will be Kent pegs. Is this an adequate beam?
Thanks

 

[munchingB]

are you saying that this lean to will have a beam fixed to a wall(the high end?) and that is the 4 8x2 bolted together? or are you saying that the 8x2s will be a truss in which case its not a mono pitch lean to.

dont understand sorry.

 

[Ducko888]

Ah yes sorry
The. 8x2 combo beam is against a wall however not attached. It is supported by two columns of the same make up, at each end. These columns are attached to the front (low end ) beam by diagonal braces.

The structure is a free standing timber frame with a lean to roof.
The low side beam is supported by two columns, one at each end and along its span by the studding also in 8x2.
So I am happy that I haven't a problem with that one.

But the high beam has only the columns supporting it. Hence a longer span.

The reason for this is that I don't want to add any loading to the existing barn framework.

 

[munchingB]

any reason that you wont attach the beam to the wall and make it a wall plate?

ive just done a roof for a lean to 6.5m using a single 6x2 into a chalk wall with resin fixings.

**just understood the bit about the barn frame..