Marks on wall between house and garage

[curiousEel85]

Hi all, So I've been helping my mother in-law clear out her old concrete (probably asbestos) garage. I've noticed this, what looks like white staining on the wall which connects to the house wall. Just trying to see what it could be.
It looks like water has been getting in and running down the wall as there is no flashing in between the house and garage.
I've tried giving it a scrub with a brush and water but after it dries it appears again..is this serious? Any help appreciated.

 

[noseall]

Hi all, So I've been helping my mother in-law clear out her old concrete (probably asbestos) garage. I've noticed this, what looks like white staining on the wall which connects to the house wall. Just trying to see what it could be.
It looks like water has been getting in and running down the wall as there is no flashing in between the house and garage.
I've tried giving it a scrub with a brush and water but after it dries it appears again..is this serious? Any help appreciated.

Looks like lime staining. Have you tried donning some rubber gloves and using a solution of brick cleaner on a small test area?

It doesn't look serious no. Merely cosmetic and ugly.

 

[curiousEel85]

Looks like lime staining. Have you tried donning some rubber gloves and using a solution of brick cleaner on a small test area?

It doesn't look serious no. Merely cosmetic and ugly.

Thank you, I'll give it a go. The main thing is it's not a kind of damp or anything damaging like that.