makie

Yep, went out and found my roll that I had. http://www.monarflex.com/Product Guide/Building membranes/Roofing underlay/Ventilated roofing underlay.aspx

I can't remember the name of it and I have a roll of it somewhere in the yard.... If it helps Geoff Capes was used in the marketing of this felt.

The ventilation issue should have been sorted before hand. Being a roofer myself I see this issue a fair amount. It will need vents installed to be properly ventilated. Roofers should have multiple roof ladders to deal with different situations.

It shouldn't cause you a huge problem, bring your concerns up to the roofer and they should explain everything to you. For the ventilation issue you need to install slate vents as close to the eave as possible.

If they don't have more than one roof ladder or one that can be extended they probably aren't that good of a roofer.

Any roofer that knows what they are doing would not fully extend the roof ladder past the bellcast.

https://www.marleyalutec.co.uk/products/aligator-rainwater-systems/

Could use hammer-fixing or anchor bolts

I would say it would depend on the render finish, colour etc. Most UPVC suppliers will have a form of trim that would work with them. I know that it is usually done with battens in England but could you not do it the Scottish way and slate directly to the wood boards? or is that against building control down there?

You could use Cupa spanish slates and finish it off with either a trim or use lead.

I've never used that company before but if you are considering standing seam I can recommend Catnic.

Sweet, I see a decent amount of people these days not ventilate their roof. I get a fair bit of work out of it so good to hear it's a vented ridge.

Make sure you have vent strips running on top of the fascia then. How are you finishing the ridge? In Scotland we tend to use ventilated zinc but I'm assuming you may be using concrete ridges?

So I would assume that you will be putting vents in the roof then, correct?

Are you going to have a ventilated soffit?