What is this cream cotton wool looking stuff inside my chimney flue?!

[Itsnotmycoat]

Anyone know? Just moved and never had a chimney before...

Cavity wall insulation, I reckon.

An aged, homemade chimney sheep ?

www.chimneysheep.co.uk

photo please

I can't get a photo as it doesn't show up... I can only see with a torch. It looks like cream, hard dust in webs. Scattered in patches. Getting it cleaned at the weekend but worried it's something serious?!

Are you worried it may contain asbestos? You can get someone to take a sample and rule that out before you touch it if you want. We had it done on a shed a decade ago and it was around 100 quid then.

Photo...

Anyone any more ideas?!

Looks like old soot build up. Don't use the chimney without having it professionally swept first.

It's white/yellow though not black?

mineral salts flowering through the build up.

Or just soot, with the crusty grey dusty ashy stuff it sometimes has on top.

Might have got blown up from the last fire and settled on what was already there.

Doesn't look that odd to me. Mind you, my chimneys had all sorts up of undesirable things up there when we opened them, so I have low standards.

If it's mineral salts will a chimney sweep remove it?

Or is there a bigger problem?

Ps thank you!!

Depending on the fuel used could be a sulphur build up. Don't worry, a good sweep will give it a clean and will advise you on fuel and maintenance.

It's not been used for a long time which is why I'm a bit worried... So there's not been any fuel in it as far as I'm aware

Been panicking about this a LOT tonight!

Is it a shared stack ?

Is it not just cobwebby soot?

Mineral salts can be brushed off. What caused the damp that helped create them may, or may not require some adjustments. Could be something as simple as fitting a capped chimney pot.

Or the white stuff might just be some ash that got blown up from the grate and got stuck to the soot.

Get a good chimney man, one with a reputation to stake on checking out your chimney properly.

And try not to worry. Chimneys are scary and wierd things (and so are their contents) when you aren't used to them. Googling tend to turn up the most expensive disasters in waiting possible, had me convinced the house was about to fall down. Not last cos I've got two old ones that looked like the bowels of hell. However the chimney man sorted them both out without any economic scariness. He takes care of them and 12 years later they are still working fine with no nasty surpises.

Thank you so much! Do you think it's mineral salts/efflorescence from the photo then? In which case I can brush off or get a chimney sweep in?

Palomb - I thought maybe cobwebs but they're too fluffy looking!

Cobwebs covered in loads of dusty shite that's been dragged up the air flow on an unused chimney. Think its pretty normal x sweep will confirm

If they are "fluffy" then that fits with mineral salts.

Personally I wouldn't do anything to my chimney, by myself, ever again.

Get a recommended chimney man in, have a professional sweep done, an inspection while he's there and then you'll have peace of mind.

light efflorescence is fluffy and brushes off as dust

heavy efflorescence comes off as crystals.

Why is it there? Is there a problem with the chimney do you think?

And thanks again for all the replies!