Damp patches and patchy paint

[jonesle89]

Hi everyone, I really hope somebody can help before I go crazy

I have been trying to get my living room into shape for a while, it was obvious the previous owner had damp problems as there was a patch of peeling paint at the top of a wall (inside the house but on an 'external' wall)
I've had all the outside rendered, the roof looked at by a roofer and gutters looked at. I decided to scrape the flakey patch, sand down a bit then repaint. Well it looks worse if anything, dark patches and paint that wouldn't stick to the wall, it was weird, There is a picture...in album. I have no idea what to do next, had a similar issue in the dining room which I can't sort yet as it's below ground level and I can't afford the work yet, but this is well above ground level I just dunno what the problem is.

Any advice?
Thanks in advance
Lucy

 

[misterhelpful]

Is there anything above that area that could be leaking (bathroom/radiator/ pipes etc)? The patch does look like it is still wet, so, if there is no problem with water penetration from outside, it can only be from something inside.

If the area isn't wet/getting wet now, and only appears that way, then you can sand back all the loose stuff to bare plaster and try applying a coat of alkali resisting primer which will help combat the salts escaping from within the wall. It is essential to avoid adding any form moisture to the wall before you apply the primer otherwise the moisture will be drawn into the plaster and as it dries out again will produce more salts which will cause further bubbling and blistering of the paint. Once the primer has dried you can fill and sand any imperfections before repainting the area.

Of course, this will only work on a wall that isn't still getting wet and even then will sometimes takes a few attempts over time for it to work.