What's caused this patch?

[cracks2020]

I don't think it's an alien hand print. It doesn't smell and it doesn't feel damp.

Thanks

 

[cross thread]

Is it dry lined . Looks like dry lining adhesive stain

 

[cracks2020]

Yes, it's dry lined.

Thanks for the answer, just don't remember seeing it before but it's probably always been there.

 

[sparkwright]

Yes, it's dry lined.

Thanks for the answer, just don't remember seeing it before but it's probably always been there.

The damp weather has probably made the blob of dry-line adhesive show through. Keep an eye on it.

 

[cracks2020]

Keep an eye on it to see if it changes? What am I to look for?

Thanks!

 

[sparkwright]

Keep an eye on it to see if it changes? What am I to look for?

Thanks!

It may look darker. The wall may feel colder and damper. More patches may show up nearby. None of this may happen.

 

[cracks2020]

It may look darker. The wall may feel colder and damper. More patches may show up nearby. None of this may happen.

Oh, I see. It could just be all this constant rain and damp air that has suddenly made it show up, or it could be an actual damp issue which is why it needs keeping an eye on?

 

[sparkwright]

Oh, I see. It could just be all this constant rain and damp air that has suddenly made it show up, or it could be an actual damp issue which is why it needs keeping an eye on?

I don't know.
It's odd you've just noticed it.

Maybe it won't notice in the warmer weather.

I can't say why you can see it, but this is a common problem.