air tight window revels plastering

esox28

Hey guys
firstly an update on the progress with our new build and to thank some of the regular posters on c and planning namely bryanf for advice with the decisions in choosing the hrv supplier, im installing the ductwork at the moment myself, inbetween chasing for electric and pricing for suspended ceiling s.

Any ways my question is with the windows revels, the 150mm cavity is full filled with 140mm eps board, I am going to tape from window to internal block and feather the taped edge with bonding to the block, the internal block will be scratch coated and skimed to the feathered edge creating the air tight seal.
t I am unsure what to do with the reveals to give the plaster a solid edge to skim?
Plaster has suggested bonding a plaster board to reveal but im worried about the point where the board meets the window it wouldn't have any succure fixing at this point, even if I was to mushroom fix the board to inside leaf.

How have you guys apporached this detail?

Thanks in advance.

newbie2013

Bonding the board to the block is fine, no need for other fixings.

BryanF

think about: thermal bridge avoidance and air-tightness with your arch, and that will dictate the plasterers backing material.

esox28

Hey thanks, first of all the internal block will be covered with the air tight membrane which is connected back to window frame across the cavity so the bonding of boards to the block dont think it will get a secured bonding at that point.!

Bryan dont think there is any issue with cold bridging at this point, external block is 75mm from internal side of window frame.

How have you guys finished your window revals ie what makes up the detail,

smellyfinger

esox28 wrote: »

Hey thanks, first of all the internal block will be covered with the air tight membrane which is connected back to window frame across the cavity so the bonding of boards to the block dont think it will get a secured bonding at that point.!

Bryan dont think there is any issue with cold bridging at this point, external block is 75mm from internal side of window frame.

How have you guys finished your window revals ie what makes up the detail,

I've used a product that screws to the window and the plasterboard slots into this. It's a metal J type shape made by either expamet or gyproc. The guys doing taping and jointing use it a lot.

esox28

Yes. Plasters recommended the j bead, I am worried bout screwing any thing to frame that may effect the air tightness levels.