Retro fit cavity tray install

[ash2072]

Hi I need some help please
About a month ago I asked for some advice on why I was getting water marks on my plasterboard above bifold door (not huge amounts).
I was advised on this forum to check the cavity tray and it hasn’t been installed on this south facing wall but a dpc was used above lintel. I’ve asked some cavity trays to be fitted only to find when I’ve got up on ladder on one side of the tray at the back there is a considerable gap 5-7cm where the back bit almost rests on the Inner brick. Builder says this should be ok as my wall isn’t straight so bit of a gap at the back my concern is before it’s all Bricked back up would this allow water to penetrate through inner leaf ..
He’s suggested trying to bridge that gap from the top of cavity tray with some kind of easy lead so it adheres to wall?
Any suggestions would be good as he’s back tmrw.
Also pls advise things I need to look out for with cavity tray
As I don’t really want to open up the bricks again
Thanks
The last image is at the end of tray which has been sealed with ct1

 

[freddiemercurystwin]

Is this the Cavity Trays Retrofit one the Type E Cavitray? Guidance is a bit poor IMO, https://cavitytrays.com/product/type-e-cavitray/ from which the sales blurb states:

'The adaptable hinged upstand automatically adjusts to fit the ‘as-found’ cavity width, providing a snug, secure fit.'

The data sheet states:

'If inserting into an existing wall containing full fill or partial fill insulation, ensure back upstand is positioned to service full width of cavity.'

So I interpret that as if you don't have insulated cavity (you don't seem to?) it doesn't need to touch the inner skin.

However IMO if any rain penetrates the outer skin it can track back along the wall ties if they don't have a built in drip and trickle down the outer face of the inner skin so I would want it to touch the inner skin in anycase and I would apply that to any other manufacturers tray. But the blurb doesn't seem to say that.

If you want a definitive answer I suspect you would need to phone Cavity Trays or whoever the manufacturer is and get them to send you a written answer (email) if you can, then you can shove that under your builders nose.

Difficult to tell but in your last photo it kinda looks like the tray is touching the inner skin? Or can you feel a bit of a gap there? Also, I am a designer not a builder so it would be good for some more hands on regulars to chime in.

 

[ash2072]

Thanks for the reply. It’s a retrofit type e tray
And one end it’s touching the inner leaf of brick but the other end due to my inner wall being uneven there is a few cm gap(hence my fingers behind the tray). He has fit someThing called easy lead adhesive tape which is moisture resistant to bridge this gap and form an apron.
Doesn’t seem to be any gaps there now.
Guess il find out if it’s done the trick. Il also apply Stormdry water sealant on the outer face of that south facing wall just to be careful and hopefully will last years to come.
His message to me is water if it comes through outer brick should drain out due to tray and more weepholes than I had before.
The dpc had failed first time due to rubble and snots he thinks .

 

[freddiemercurystwin]

I edited my first post, (added the bit about a drip on the wall ties). Looking back at your other thread if this a new extension then where is the cavity insulation? Or is it internal insulation?

 

[cdbe]

Personally I'd be doing a bit more investigation. The location of the tray is fundamentally wrong.

That old lintel should have been removed as water could be tracking back across it.

The other windows have no weep holes to let water out.

The 3 courses of brickwork below the incorrectly positioned tray have no weep holes.