Waterproofing around window fixing straps?

[HEB1]

After horizontal rain blown at 50mph into our newly sealed windows - we've got water pouring in through every fixing strap. I had assumed the windows would be set into the reveals until local regs up here in Scotland dictated that 50mm of the frame would hang outside the cavity as we are cladding with cement board. 

 

 

How on earth can I insulate/waterproof around all those fixing straps - (Door fitted by well respected local window company)

 

 

 

I have TP600 tape on the outer edge of the window to timber batten, Soudal SWS foam from the inside then Everbuild 625 Silicone around the edge but only a couple of mm  gap between the window strap and the reveal. This is where water is pouring in and I seek advice on what to seal the gap with please.

 

 

 

 

Edited September 14 by HEB1
Wrong picture format

[MikeSharp01]

Going to be tough until you get the cladding on and can seal the frames to that. I would just run  bead of silicone round them all until then.

[G and J]

3 hours ago, HEB1 said:

50mm of the frame would hang outside the cavity as we are cladding with cement board. 

Is that to create an unbroken layer of cement board and window?

[HEB1]

I think more to do with Firestops surrounding the window but certainly easier to clad we hope!