Help! Corrosive substance

[Harburt]

Hi all

A year or so ago. I had new bifold doors fitted as part of my kitchen renovation. A few months later I noticed a strange waxy/gungy type substance leaking onto the edge of the frame where it meets the plastered reveal. I thought nothing of it to start with, but it kept coming back and low and behold it has corroded the black paint off the frame. I'm wondering if it's even eating ever so lightly into the surface of the metal below.

The paint has also come off the plaster as well.

It's very small and only appearing in a couple of spots. It seems to be persisting as well. I was hoping it might have stopped by now but it just seems to keep coming. It's worse in summer.

Any ideas what it might be and how I can stop it eating any more paint off the frame? I am going to silicone the edge to hide the exisiting damage but I want to stop the leaking substance first.

Photo of the damage attached.

Thanks so much

 

[blup]

Is the frame properly sealed or can water get in any other way? That gunge might be watery rust from fixings that moisture has found its way to.

Blup

 

[Harburt]

Hi Blup

I am pretty sure it's sealed though hard to tell. The brickwork was rendered after the installation. The render isn't sealed to the frame but the brickwork beneath might be.

That being said, the residue coming out is very waxy in consistency. It feels more like a melting adhesive.

However, to add to the mystery, there are also these strange stains on the underside of the render above the door frame outside, which look like something is leaking/has leaked through at some point (see pic below)

I am baffled

 

[CharlesBR]

I have no clue what it is but what have the building contractors said and is there a warranty for the work carried out?