This involves things like splicing the wall plate, repairing rafter ends and changing the gable ladder on one end (the whole roof should really be replaced but I've been shot down on that due to the councils tight budget so I'll just do as I'm told).
I did have an argument with the structural engineer when he came as he originally said that a prop in the roof was doing nothing (it was under so much tension you could play a tune on it)- but to leave it in just in case (this way he wasn't going against his original survey. I wasn't really very happy with this answer, so I got him back out to look again, he then agreed with me that something should be done. I suggested a high level purlin should be added, he just needed to tell me the size.
In the end it had to be 250mm x 100mm by just over 5m long and to be C24 strength. It took ages to find someone who stocked a timber this size and strength (most suppliers stock up to 4.8m and normally only C16 strength), still it turned up yesterday so today I could have a bit of extra help to get it into the roof.
I wont say how it got up there for many reasons but it involved 5 men and quite a bit of grunting. Once it was in the loft space I let the other guys go to another job, just leaving just another chippy and myself to fit it. A little brick work making a recess in the gable wall to take it, then packing it up with slate and using mortar to fix it in. I think it was at the limit of what we could lift between us but we were both really pleased when we could take the old prop out and have the rafters sit on the new purlin.
I think I'm doing the rest of the repairs on my own, should keep me out of trouble!