Header for top plate and support

[JimBobbins]

I'm planning a 3.4m long front wall for a garden room build, with a 900mm doorway and a 1900mm wide window opening. My plan is to have a double width 6x2 across the whole span of the wall to act as a header and top plate combined (due to restriction in overall height, squeezing it all in under the 2.5m permitted development). The space would then allow for 4x 2x4s at either end and 4 2x4s between the doorway and window. Does that sound like enough support? Effectively 12 2x4s supporting the header.

The back wall has no openings and will have 11x 2x4s supporting a standard double 2x4 top plate.

Thanks, Jim

 

[Jameshow]

Needs more details - what's the roof design?
The window is it several panes or a single big one?

 

[Jones]

Span on double header sounds ok. The number of studs seems excessive by a factor of two. I presume the window doesn't go to the floor so you have bracing to prevent racking.

 

[JimBobbins]

Roof will be single pitch 5x2s at 400mm spacing, with OSB and EDPM.

Window is not to the floor and wall will be skinned with 11mm OSB, so should be no racking.

 

[JimBobbins]

Revised design. Thinking this should be fine…