Basement flat - bumps on outside wall

[pearcej]

Hi there

I live in a victorian terrace basement flat. Over the last month or so, the outside wall has developed quite a number of noticeable raised bumps - like boils. The masonery paint hasn't cracked but I'm wondering what has caused this and how best to remedy it. Any ideas?

Cheers
J

 

[JohnD]

photos please
//www.diynot.com/forums/viewtopic.php?t=129539

When was the wall last painted, when was it last rendered, how long have you lived there?

 

[sedgefield]

I presume you mean the boils are occuring on the inside of an earth-retaining wall. If so it sounds like someone has tried to waterproof the basement and done a poor job. This is often a problem when people try and use a cheap "cellar paint" rather than a proper tanking slurry - or where they do use a proper tanking slurry and fail to prepare the wall properly first.