Bulges and cracks on internal walls

[DAW]

Hi all, over the last year, one or two bulges have appeared on internal walls - about 3 to 6 inches in diameter, only one each on 3 different internal walls. Solid walls. not stud walls. On one, I have removed the loose material. Hopefully some pics attached below.

Anything to worry about or just remove loose material and fill in ?

Thanks for any help.

 

[KenGMac]

DAW, good evening.

Are any of these bulges on opposite sides of the same wall? And are all the bulges [about] the same height from floor level?

In the image posted, the one with the plaster removed, it appears that there is an old metal pipe or similar embedded in the wall? if so the metal has rusted and expanded to force the plaster away from the brick.

If indeed this is the case, remove as much of the metal as you can, and proceed to fill.

Ken

 

[DAW]

Hi, thanks for your reply. No, the bulges are on different walls and at different heights. The opened hole is the only one that I can see the black substance in but then I haven't fully opened up the other bulges.

 

[KenGMac]

DAW, good evening, again.

Quick no mess check??? use a magnet

Ken.

 

[JohnD]

is the house made of concrete?

are you in a steelworks or mining area?

 

[Deleted member 292770]

looks like old ash/coal mortar .
where in the country is this.
theres hygroscopic salts behind the paint .
it’s a complex issue that you need to research but in a nutshell you need to scrape the loose stuff off as the salts just absorb more moisture making the issue worse.