i think the point is, insulation is sealed so its hard for moisture from inside the house to travel through it and meet the dewpoint. Worse would be if the dewpoint made it through the insulation and into the blockwork/plasterboard etc.
i was referring to and linked EPS, unfortunately i have dyslexia so autocorrect doesn't always catch everything.
Here is the standard buildup giving a U value of 0.103 against a min spec of 0.13
https://flooringwarehousedirect.co.uk/product/jablite-polystyrene-insulation-board-150mm-eps70-2400mm-x-1200mm/
Travis are cheaper for us though at £6.25 /m2
why are the ridge tiles overhanging the gable ?
personally prefer a dry valley with short upstand with tiles cut tight to get rid of the gap, looks tidier.
make the windows work brick, adjust them a few mill either way so you end up with a half brick.
One of the many things architects are clueless on, specifying widow and door sizes that dont work brick.
interesting.
from my understanding, brushing a sloppy sand/cement mix over them prior to dabbing ensures any tiny shrinkage cracks are sealed.
Agree they should be gagged properly anyway but it doesn't take long to brush a slurry over them for belt and braces.