New common rafters

[Rebateman]

Hello Folks
I need to sister
along side existing ones and i am a little unsure on how to
configure it. The new rafters are 47 x 150 and the existing are 50 x 100m. If i cut a birdsmouth to suit the plate i would be taken more than a third out the rafter which obviously is a big no no. So do i move the plate forward to get over this? The pictures show some offcuts i used to figure out how much the plate would have to move forward which is exactly 80mm

Any suggestions, comments welcome

 

[ted456]

Dont attempt to move the plate.
Use same size rippings of 22mm ply screwed through the ply well into the rafters - you could even sister both sides of the worst splitting rafters.
No need to worry about birdsmouthing the rippings just cut them level with the plate.