Dirt around windows - is the double glazing faulty?

[PunishmentRoundupWithJoon]

Wasn't sure if this should go in Housekeeping or Property. I live in a small high rise flat (housing association) and on one wall there is a large triple window and door to the balcony, it takes up all of one wall. Years ago, they replaced the windows and door with. presumably, something more up to date - upvc? I have no idea about these things!

Since then, there is always a layer of dirt around the windows and on the door on the inside. It's not dust, it's black, the same type of stuff that gathers on the outside (I live on a busy road). Clearly, it's getting in somewhere. Is this normal for double glazed windows?

I open windows elsewhere in the flat, and there is another window in the living room that is opened regularly, so it's not that the dirt is flying in when those windows are open.

I'm just wondering if this is normal, over a period of years? I always presumed that double glazing was sealed against draughts and muck!

Yes unfortunately it is normal - or at least, we get it and our windows are pretty new.

@Pootles34 - Thanks for your reply. I'm shocked! Didn't realise this was possible. At least it's not just me....

I think you don't realise it's there because the sealant is black, then suddenly realise after years of it building up... it's pretty gross by that point!

Actually, it's on the white part of the frame on the inside, but because it's high up behind the blinds, I only noticed how bad it was up there today (I'm not big on cleaning!) when checking a blind fixing. I had noticed it elsewhere and would wipe it periodically but it was really bad high up.

Sometimes when it's very windy, there's a whistling noise too so there could well be a gap somewhere. The housing association employ bloody cowboys.