Hip end - ceiling joists/restraint

I'm building a hipped roof on the first floor part of my extension. I've got the ceiling joists up and have realised that the last one will be in the way of the rafters.


I gather that I need to remove it and fill the gap with infill ceiling joists. Do I just go from the one behind? (400 centres) and do I need to restrain the front wall, eg with a binder along the ceiling joists or similar? I had been wondering what prevents the hip thrusting outwards before I got to this problem.

Thanks.

cdbe said:

what prevents the hip thrusting outward

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There is no outward thrust from a hip rafter.

And yes, joists like your sketch, no further restraint required.

You can put a piece of timber across the corners where the hip will sit at 45° wall plate to wall plate 4x2" should do, that will lock the corner in, used to be called a dragon beam.

Thanks, I'd seen the dragon ties, or something similar that involves a piece of plywood and a twisted metal tie that seems to the same job.