Extension - rafters to wall plate?

[RadioShack]

Good morning!

We are having a 2-storey extension built - cavity blockwork joining existing brick walls. As per SE specs - extension top wall plates have been fixed to the internal leaf. The trouble is - existing wall plate is fixed to what appears to be a course of bricks bridging 2 brickwork leaves of the existing wall. This results in wall plates not being in line (see photos) and rafters cannot be fixed directly to the extension plate.

Adding a 2nd plate on top of the ceiling joists has been considered but posittioning it directly above the 1st plate (and the inner leaf) would not allow for birdsmouth cut (not enough rafter depth - see 2nd photo).

I've contacted SE for advice but he's on leave and it might take a while.

Would be grateful for some advice please - I've read similar posts but haven't came across similar situation

 

[blup]

Not sure what you're saying, its a flat roof extension that will be stepped in or need some cladding/insulation to bring it in line

Blup

 

[RadioShack]

Hi, thanks, it's a side extension and hipped roof. Existing hipped end has been demolished and new rafters are being installed to match exisitng part.

 

[martygturner]

Why can't they builder just cut a slot for the rafters to pass through the new floor to the soon to be added wall plate. he has laid the joists out for the floor to the right spacing for this.

 

[RadioShack]

There's no floor yet - the board visible on the photo is just a sheet of osb placed there temporarily.
Not sure how to explain this - If they would use 2nd wall plate - it won't fit straight above 1st plate (red rectangle) and needs to be fixed to ceiling joists roughly where the green rectangle is on the photo. So the weight would rest on the joists and would not be directly supported by the wall underneath.

 

[martygturner]

But that's the hip end if you description is correct and the rafters will not be fixed to the joists. So your builder has cut the the joists so that the hip rafters can sail over them and meet the soon to be installed wall plate that will carry on for the existing one...So what you think is a wall plate is not one its just a joist support. You can see that has he has changed the direction of the joists .in the new part.the hip end will be connected to the joists

You will have smaller jack rafters up to the transition to the hipped end.