liammcl

My only concern is if there's scope for water to creep in the seams of the external eps behind where window or doors are mounted then it needs a membrane lapped over trays etc. to prevent this..

In my mind it should be treated the same as a timber frame building once outside the ICF block. - As in you need membranes & trays to act in the same way. It amazes me its not addressed more clearly on the manufacturers websites.

I'm detailing my own ICF build now with a very similar problem regarding walkout basement, tanking and stone outer leaf. Our basement is a walkout with the ground sloping down either side. Same as you, I didn't want to use a brick ledge as they're a nightmare to execute well so increasing the foundation width to take block/stone all the way up. I've attached what I've drawn up so far. The guys at Newton are very helpful, they're happy for the tanking to come through the outer leaf like I've drawn although it needs a protective layer before mortar bed and bricks/stone. Also using Type B to some extent (waterproof concrete & injectable water-bar) + Type C internally. Note: I am by no means an architect of any sort(I detail steel framed buildings) but have been involved with building & civils for long enough to have an decent understanding. basement drg extract.pdf