The assumption here is that your electrician or cabler will be prepared to accept your work is to code/standard?
It might pay to check with your friendly tradie first. They may be happy for you to crawl around the roof and not them? In which instance they will probably supply the cable and any conduit required and some guidance about separation from 240v cables etc to you. They get the cable etc at a much better price than most of us ever could.
I much prefer to send in the sacrificial apprentice, appologies youthful trainee who’s safety will be managed by turning of all power first and ensuring it’s not too hot up there. Risk management is important. There are other hazards but I assume the pythons can usually take care of themselves.
I’ve in more than one instance removed selected roof sheets at the key locations above where I need the services. This assumes your house is suitable for getting the cables down the wall cavity. It makes access so much simpler, and reduces your risk of needing a difficult emergency services rescue after you have a heart attack in the roof.
It’s also a great way to speed the tradie up if you have them do the cabling and you have agreed this need before hand. I’ve also put batts in three houses and would now always do it by removing sheets for access and ventilation if you do choose DIY.
