We had bifold doors installed a while back and are now getting water leaking through the lintel above the doors during heavy wind/rain. Our builder says it can't be the cavity tray that's at fault as all was fine for about a year before we started having issues.
There is a double rsj over the doors and a borescope has shown that there is a plastic membrane running over top of rsj but at the point where leak is there is a big mass of concrete and water is seeping round eges of that.
The point where the leak is where we had a wall removed and what i suspect is that the builder has attempted to join the cavity tray that was over the old patio doors (that reached to where wall used to be) to the tray that was over the old backdoor (that was on other side of wall) with cement and now that's leaking.
The surveyor we had out said the water is not going out of the weep holes but is instead penetrating down behind the render and getting out that way so guess it's hanging around in the tray, working it's way around the cement.
Basically my builder is refusing to come out and fix the issue and I am beginning to doubt myself so just wanted some advice really.
Does it seem as if the cavity tray is the issue? Could there be a genuine reason why there is cement where I'd expect to see cavity tray?