Cavity Tray, brick courses, weep holes ...

[Casterbridge]

Bear with me please, never done this before, but I am proposing to build a small cavity wall four courses high and have a folding door on top of this. I plan to use a damp proof membrane and bed it two courses high on the outer wall and three courses high on the inner wall. I intend to bridge the gap with some steel plates and then place the the folding doors on to that. The cill will have holes in the centre to weep away water, so I intend this to drip down the DPC and hit the outside wall and weep away through weep holes at secon course level two bricks apart?

Any advice really appreciated.

 

[jeds]

For 3 courses I'd place a thermal bar across the cavity directly beneath the frame with a full width dpc over. The frame should drain onto the sill which presumably is external so will direct any penetrating water to the external. Steel plates bad idea - will cause cold bridge and condensation and are unnecessary anyway. Might also be worth insulating beneath the frame?