Hoping someone can offer some advice please. In the middle of a long renovation of our upstairs. Ended up back to brick. Have applied diathonite lime insulating plaster and wood fibre board to external facing walls. Internal walls and ceilings have been re-skimmed with gypsum. Our amazing plasterer is going to give baumit rk70 and then glatt a go over the woodfibre boards after the lime plasterer I found (with difficulty) had to cancel due to illness. The system seems fairly straight forward (though advice welcome!) but he has very little lime experience so trying to help with research as much as I can! Our main issue is how to deal with the joins between the lime and gypsum. Our upstairs is in the eaves so we have joins at some internal/external wall corner, walls/ceilings, and a couple of verticals wall sections where the top half is gypsum (dormer cheek) and bottom is lime. We have discussed stop beads and mesh options but any thoughts appreciated!

Thanks for that. I completed all the insulation aspects before the internal walls were tackled so not worried about air tightness etc. more just wondered about the join between the two types of plaster. It’s my understanding they don’t merge well?