Tyrone

Hi guys/gals, I’m a newbie on here so hope I’ve put this in a relevant place. Next March/April the loft conversion and rear extension are kicking off on my 2 bed end of terrace bungalow. Me and my brother will be doing about 70% of the work, I’m and Electrician and also can do plumbing, getting in a friend to do the roof and rear dormer (as it’s a truss roof). so getting to the point, me and my brother will be removing all of the existing tiles and bringing down all trusses and existing joists. Tell me if this sounds hopeful, but I was looking at getting a 20M x 15M tarpaulin and covering the entire roof, and just putting in a temporary ridge to let the water slope off. This will have eyelet holes and be fixed to external walls. Firstly, would you recommend rear and front scaffolding at eaves height to remove the tiles/roof (if so, any idea on costs)? Or could we just have a movable tower hired? secondly, I need to talk to my chippy friend about this really, but would we need scaffolding for the new timbers being installed? I was thinking that the ceiling joists would be installed from wall plate to wall plate and then that would give us a floor to stand on for installing the rest above? Once all in I can put down the breathable membrane to make it water tight. thankyou in advance for any advice. Here is a picture of the plans just to give you an idea.