Black bits coming out of seal

Lizzie444

Would anyone know what this is, it's on the inside of a window frame

Jeepers_Creepers

Hmm, not sure what the 'gritty'-looking bits are, but it's not uncommon to have the sealant used on the installation become a bit mouldy over time - mine certainly does.

If it is sealant - and it looks like it - it ain't the neatest; when the top trim piece was fitted, the sealant was squeezed out and wasn't tidied up properly. That's what it looks like anyway! I'd therefore be tempted to try and trim away as much of that sealant as possible first. If you run a craft knife blade along that, nicely and gently, it'll sever the sealant away from the rest of it which will remain between these two sections doing its job.

The way to do this is; you have a flat surface on the main frame, yes? And a 'rounded' trim piece between the frame and the ceiling? Ok, place the side of the blade firmly against the top trim piece, so the knife is held parallel to the ceiling and the tip of the blade is cutting gently into that sealant, and the very tip is touching the flat frame. Now pull the knife along steadily, using the top trim piece as its  guide. Once you've done this, you should be able to peel that severed sealant strip away, perhaps having to use a scraper to lift it away from the flat frame. It all should come away very neatly.

Clean it up further bits using Jif and a cloth.

Any remaining stains, apply mould-killer and leave.

Lizzie444

Thanks for the reply, it seems to have got worse since we had new fascias, we are having new windows soon but even the man who measured for the new windows doesn't know what it is and neither does my next door neighbour who fits windows, I'm hoovering the window sill everyday because there is so much dropping from the top

Grenage

Dirty rockwool insulation?

Lizzie444

Is it coming from the insulation in the loft then

Grenage

The voids around the window are normally stuffed with insulation.  Draughts through the cavity often blow dirt around and it catches it, ending up a yellow and black mass.

You could push it back up using something thin and then seal the gap using sealant (I use white sanitary silicone on PVC trim).

Jeepers_Creepers

Lizzie444 said:

Thanks for the reply, it seems to have got worse since we had new fascias, we are having new windows soon but even the man who measured for the new windows doesn't know what it is and neither does my next door neighbour who fits windows, I'm hoovering the window sill everyday because there is so much dropping from the top

Quite different then!

That's a mystery. Are you sure it ain't tiny insects of some sort - no movement from them at all?!

The problem should be gone with your new windows, and if it's caused by anything behind the frame this should become obvious too - please keep us updated!

Meanwhile I think I'd give it a spray with 'Mould & mildew blaster' - it'll not only bleach any stains, but will almost certainly also zap the stuff if it's organic...

Lizzie444

It's definitely not insects

Another_Level

Oh great its not insects or their nests ! its a question that needs asking.

maybe cut off the protruding black stuff and see if its damp or smells. 

Tbh the debris could just be unknown material/debris that has moved during the other work mentioned or summer expansion. From the photos it looks like a void has developed between the upvc cloak & upvc window frame, could be 100% wrong thou. Fix could just need to rake out and simultaneously  vacuum out the unknown black material and apply a quality silicone pushing it into any irregular void and finish with an appropriate  cramer fugi tool.

IIRC there are always other avenues which will achieve the same results but with a cost difference 

Lizzie444

I have touched it today and it doesn't smell and it looks like soil

Jeepers_Creepers

Does it wipe away, or is it rubbery?