I'm using woodfibre EWI on my old timber framed house. There are some sloping roofs adjacent to the EWI walls, which will have new flashing to prevent water getting into the gap. The suppliers of the EWI have said that the flashing would have to go right behind the EWI but I've insulated the entire wall from below the roofline without making a join at the roofline. So now I need to do the flashing and I've read on here that it's not good enough to simply run the flashing under the render. Why is that?
So would it be better to:
a) run the flashing up the wall say 150mm, tack it to the EWI, screw a bellcast drip bead ontop of the join, and render down to the drip bead
b) make a small cut with a handsaw into the EWI, say 20mm deep and sloping to the outside, tuck the flashing into this, screw a bellcast drip bead ontop of the join, and finish as above.
The EWI is made from a breathable woodfibre material, fully impregnated with a parrafin wax waterproofer, so cutting into it would not impair its weatherproofedness. The insulation layer is 60mm thick on some elevations, 100mm thick on others.
Thanks for any help

Posted By: zebra...and I've read on here that it's not good enough...

It might be worth linking to what you've read. Somebody might know why it's not applicable to your situation or something.