Monopitch roof design

[SpecialK]

Hi,
I'm starting to the think about the roof on the extension I am trying to build!

Its a 3.3m clear span (wall to wall) with a vaulted ceiling. Am I right in thinking I will require 170x47mm timbers at 400mm spacing? On the tables it has gk of not more than 0.50 - What does this mean? I'm probably going to use concrete tiles with 3 velux windows.

On the house wall side I have two sections of tiles (pictured below). How do I span these with the pitching/wall plate? Do I remove the tiles and pack out from the internal wall with timber? (The stairs window is being reduced in height)

Is it best to notch the timbers at the house wall plate or use hangers?

How do I finish the roof on the sides? The last rafter sits next to the inside wall, do the wall batons then span across the wall and stick out a bit with concrete sheet underneath and then the verge finished with mortar? Would the batons need screwing to the wall at all or are they OK to support that width?

Any help / tips gratefully received!
Thanks...

 

[catlad]

I would take the tiles off and pack the studwork out to the brick level. birds mouth top and bottom is good practice. There are a few ways to finish your verge, try looking on google images.

 

[^woody^]

Verges have a cut up or a ladder and bargeboard.

Don't you have any plans?

 

[SpecialK]

Thanks

I would take the tiles off and pack the studwork out to the brick level. birds mouth top and bottom is good practice. There are a few ways to finish your verge, try looking on google images.

 

[SpecialK]

I do have plans but as I go on they seem to be more waffle than actual detail on the building regs plans!
I have just noticed most lean to roofed extensions around here just seem to overhang by about 50mm with no barge(?) board .. so probably not ladder type as there is no room?

Just looked up a picture, so it appears OK just to have the roof batons span some of the wall? I was just worried they wouldn't be strong enough

Verges have a cut up or a ladder and bargeboard.

Don't you have any plans?