Cavity tray / cavity closer detail

[flanagaj]

I have searched the internet, but haven't discovered how you terminate a cavity tray at a door opening and get a proper seal.  As we have a DPC for Radon directly below the tray which spans the cavity, any water that gets through the tray between the cavity closer and the cavity tray will potentially cause damp.  The image below shows how water getting under the cavity tray will have no where to go except towards the inner leaf.

 

 

 

 

[Oz07]

If it gets as far as that joint its out the building though isn’t it? In reality I think you will leave the blockwork out at doorways so the radon / dpm will turn up the inside face of the brickwork.