Cavity Tray Advice

[eeyore2]

I'm about to fit out my brick built, single skin garage as an office using stud walls set away from the brick and leaving a cavity. The garage has windows already in and I guess I'll need some form of cavity tray over them now?

Is the only way going to be by cutting a slot in the wall to slide the tray into place?

On 2 windows I could probably cut out the mortar above the lintel and slide it in there, but on one window I'd have to put the tray below the lintel between it and the top of the UPVC window. The reason is that here it's already a double thickness wall with no cavity. I'll be creating a cavity when I build the stud wall.

Also, where I have the double thickness wall the "reach" of the tray needs to be about 230mm. I was thinking of using a tray with a prefitted lead flashing to achieve the distance. Is that OK?

The work is all going to be seen by the Building Inspector so it has to be right!

 

[noseall]

do you live near the sea front?

if not i would not bother with cavity trays.

 

[eeyore2]

We're close but not on the seafront.

I've already seen wet running down the inside of the single skin wall so I'm keen to avoid any problems over windows etc when the stud walls are in place

 

[tawelfryn]

I should imagine, being a single storey garage, there wont be many courses of brick above the lintel anyway?. (unless a window is on the end, with a small gable above it? but this method can still be done) The proper way is to take these courses out, at least a brick (or brick and a half so that the ends can turn up into the perps of the above course) either side of the opening, and put your tray in then. rebuild and like said the ends turned up into the perps above, with a weephole in place.
Not too much of a problem to do