What is this weird patch on my newly plastered wall?

[Warmduscher]

Just that really. It doesn’t feel damp to the touch but I’m going to be decorating this room next and I’m not sure how I should make sure it doesn’t come through the paint.

I’ve got a horrible feeling the answer will be that I need that bit hacked off and replastered :(

How long ago was it plastered?

Salting or efflorescence.

@dementedpixie

How long ago was it plastered?

April this year.

Or lime coming through. I got rid of lime staining on quarry tiles by cleaning with bleach and leaving to thoroughly dry out but I’m not sure that would work on plaster.

Can you pan back a bit? I'm wondering if it's an air pocket?! ... not that I'm any expert in the field - we had our whole house (12 rooms and two hallways) plastered last year and not seen anything like that

If you’re certain there’s no external or internal cause for damp or leaking it might be worth treating with a salt neutraliser.

@custardbear

Can you pan back a bit? I'm wondering if it's an air pocket?! ... not that I'm any expert in the field - we had our whole house (12 rooms and two hallways) plastered last year and not seen anything like that

Any better? The patch underneath also looks damp but isn’t, and has no crystally bits.

Excuse the emergency curtains - we’ve not long moved in

@DentonsFringeArnottsWaistcoat

If you’re certain there’s no external or internal cause for damp or leaking it might be worth treating with a salt neutraliser.

Pretty certain - we had the ridge tiles on the roof next to that part of the wall replaced a couple of months ago.

Salt neutraliser sounds like it could be worth a go. I would try bleach but the smell of it makes me gag (clearly not a true Mumsnetter ).

Looks like the roof of the bay window is not draining properly or the roof finishes are leaking.

Is there a rain water pipe outside draining the bay window roof?

@SkiingIsHeaven

Looks like the roof of the bay window is not draining properly or the roof finishes are leaking.

Is there a rain water pipe outside draining the bay window roof?

The bay window roof was refelted at the same time as the new ridge tiles fitted. The roofer checked all the guttering and said there is no damage or holes. However, maybe it leaked before and the wall was damp when it was plastered but it’s not getting any worse because the cause of the leak has now been fixed?

Looks like a leak !! Hubbi is a plasterer just shown him the pic x

@Hairobsessed123

Looks like a leak !! Hubbi is a plasterer just shown him the pic x

Oh balls.

I’ll have to get the plasterer back to hack it off. Luckily this is mine and DH’s room and we can live with it until I can get the plasterer back.

Maybe check for a leak as well I’d get the roofer back to have a look x

@Hairobsessed123

Maybe check for a leak as well I’d get the roofer back to have a look x

Good shout. Thanks all

DP is a plasterer. He says:

"It’s efflorescence. Salt from the sand that got used. Probably wasn’t cleaned before it was sold to the builders merchants.
I’d say it’s not the persons fault who did it.
If they're having more walls done I’d advise them to put a salt inhibitor in the sand and cement coat.
I’d advise them to go to the paint merchants and get their advice on what products they can put on it so it can be painted."

@JeSuisPrest

DP is a plasterer. He says:

"It’s efflorescence. Salt from the sand that got used. Probably wasn’t cleaned before it was sold to the builders merchants.
I’d say it’s not the persons fault who did it.
If they're having more walls done I’d advise them to put a salt inhibitor in the sand and cement coat.
I’d advise them to go to the paint merchants and get their advice on what products they can put on it so it can be painted."

That’s great advice, thank you.

We haven’t bought paint for that room yet and we buy our paint from the Dulux Decorator Centre nearby so they will definitely know what to recommend.