Fascia pulled away from house

Hi, My old 1910 renovated aussie style bungalow has the fascia pulled away from the house for part of its length. Upon examination I can see that the roof rafters are not bird mouth jointed to the top wall plate. They are just sitting in top of the ceiling joists and skewed nailed. ( That was the way i guess back then). I imagine over the years that the timbers have sagged and pushed outwards a little resulting in pushing the fascia away where this has occurred. I think the fix is quite simple. I need to cut away the over hang of the rafters so they are flush with the end of the ceiling joists and then screw the fascia back? But how do I stop it happening again should I gang nail or strap somehow the end of the roof rafter to the side of the ceiling joist that it is sitting on. There are rafter ties between each side of the house but they are at about 2 m above ceiling height and may not stop the roof rafter from sliding out. I hope this is clear and that some one can give advice. If not I can get a photo if it helps. thanks Hammo

Photos would help, both of the end of the rafters and up into the main roof space.

Stewie

Be nice to see a picture so as to be a bit clearer on what is involved. Birds mouthing the rafters has always been done, but sometimes on simple houses they may have left it out (sloppy workmanship is not just a symptom of the 21st century!) It could be you have an undersized ridge and its sagged, pushing the rafters down, or the rafters might be undersized for the span and they have sagged and pushed forward. Are your rafters attached to the ceiling joists? Sounds like they may not be and with only two rafter ties the roof over time has sagged. Or might be a combination of those. Your fix for the fascia sounds about right. As for insuring there is no more movement, without looking, I'd say make sure rafters are attached to ceiling joists, more rafter ties, and Simpson rafter clips to top plate.

I just remembered I saw a roof that had moved like this before and when you looked at the connection of rafters to the ridge they had pulled away by a couple of inches. using plywood and cutting a gusset to reconnect the ridge and rafters can secure this.