Door and window opening

[bolst3r]

I'm building a garden office which is timber frame with the following construction:

Pb>vapor barrier>insulation>wpb>membrane>batton>cladding

I now need to add an opening for the door and windows but not sure how to do this. I assume for the windows I just create a frame in my stud wall to the required size, then order the window and once fitted cladd up to the window frame putting a small bead of silicone between the two.

For the door, I'm happy to have a small step in <6", again do I just create a frame for this as above? Or is it better to omit the floor plate where the door opening is effectively creating two walls either side of the door opening with a bridge in the middle joining the two?

Not sure if I'm over complicating things...

 

[big-all]

your framework must carry on above any windows or doors and be off sufficient size for the compression and stretching loads without deflecting unduly

is your roof a sloping or an apex roof
http://s21.photobucket.com/user/bigall2005/media/e1e47346.pbw.html?sort=3&o=0

 

[bolst3r]

Ok, was going to run horizontal noggins across the top of both the door and window frames. All structural work is 4x2". I'm going for a warm deck roof which is flat, again using 4x2 at 600mm centres.

 

[big-all]

what length is the unsupported span off the roof

 

[bolst3r]

From front to back is 3.2m so the longest unsupported run is just under 3m. Will have 4x2 roof joist over each vertical upright which are set at 600mm centres and each roof joist will have 2-3 noggins. Roof wise it will be 12mm wpb, vapour barrier then either 50 or 75mm celotex. Roof material is epdm so much lighter than felt...

 

[big-all]

its not necessarily the roof weight its the snow loading or you on the roof

no expert on spans but would want to double check 4x2" on 10ft

 

[bolst3r]

Ill check timber spans thanks, any idea how to construct the window and door openings?