Plaster problems in hall and kitchen - 'blistering'

[peteuk]

Dear all,
Can someone give me some advice about my plaster please?
Pictures can be found at the link below - if I've done that right - great system but I've never uploaded photos before so hopefully ok. I shrank the photos before posting so have better ones if they are unclear.
http://network.diynot.com/peteuk/albums/
The name of the album is similar to this subject
We live in a bungalow which was empty for 18mths before we moved in about 3yrs ago. It was flooded during that time because they didn't keep the CH system on - replastered by the previous owners. We assume there was some wet then.

We have also had a bad leak into the roofspace (probably since the house was built) which we fixed last year (Water was dripping from the water soaked joists in the loft - we assume it was then being absorbed by the walls, this is about the right area)

The walls have got worse since we moved in.
I think we may have 2 problems - wires not chased in deep enough & an effect from the damp.
The affected walls are internal brick built walls and do not appear damp, we have no visible mould.

Can someone advise how we treat this? I am worried that if I simply ask a plasterer to come and replaster the problem may recur. I have heard a membrane may be needed?

Thanks to all
PS I will make a separate post re a different plaster concern in our small bedroom

 

[roughcaster]

Pete,
Where the cables need to be chased deeper,the answer is simple, although taking great care. The other bumpy/bubbly areas look as though it could be efflorescence/salts coming through from the bricks into the plaster beneath the paintwork, especially if there has been a flood in the house. You would need to scrape away a bit and see and take it from there.

Roughcaster.

 

[peteuk]

Thanks Roughcaster. Sorry I hadn't replied earlier, I thought I'd receive an e-mail to say a reply had been made (maybe due to internet access problems I'm having.....)
Anyway,
I'll ask the plasterer to chase the wires in more deeply when we do the repair (My wife will love that because the walls are solid red brick, lots of dust!).

When he takes the plaster off, what should we be looking for? There is a post http://www.diynot.com/forums/viewtopic.php?t=128679 about efferscence which sounds like it may be the same thing.
The membrane idea seems a bit drastic but the idea of using lime plaster and porous paint sound ok. Would the whole wall need to be done or is a patch repair possible?
Will a plasterer be able to diagnose the problem immediately so we can go straight to the solution?
Thanks again

 

[tommyl18]

if the rest of the wall is ok just scrape the loose plaster off make sure the wall is dry and give it a good unibond and patch it unless its a small wall then the plasterer will probably charge ya the same price to skim the complete wall

 

[joe-90]

Most of that damage looks old to me. You could sand it back with green sandpaper, 40 grit then 80 grit and you'll lose nearly all of that rough stuff.

 

[trowelmonkey1]

agree RC! Definitely efflorescence in some of those pics and can almost hear the hollow sound of the blown plaster, most just above skirting level too.

also agree with joe that it all looks like old damage, if you've been there for a while and it's getting no worse t sounds like you've dried the building out and the damage has been halted, if you cut out he blown plaster with a knife you may well find white powder behind (efflorescence) brush this away and keep an eye on it for a while, if it gets no worse then you're probably safe to get the plasterer in to 'make good' or skim.

 

[peteuk]

Dear all,
Thanks for the recent replies. You can imagine I didn't expect any after this time but it is greatly appreciated.
The wall was sanded back and repainted based on the advice of a decorator and unwillingness on my wife's part to listen to advice that I found on the internet. LOL!
As expected the marks have come back but to a lesser degree. So as suggested by your good selves my conclusion is that it is old damage caused by efflourescence.
We'll go with the suggestion from tommyl18 when we get to it again later in the year. The boss doesn't like trowelmonkey1's idea of leaving the area unplastered for a while although that would be my option to ensure it's a permanent fix.
Thanks again I really appreciate it.
Pete