Damp on new plaster and chimney breast

[EDDIELJH]

Hopefully someone can help me, I have been renovating my house over the past year and have just finished the downstairs only to find damp and salt coming through the new plaster.
The new plaster has been painted with emulsion and some of the new plaster has now cracked and blown, it looks like damp and salt coming through the paint.
This is happening on the pine end wall and down the chimney breast.

I have had numerous builders out and some say I need new rendering and some say its the chimney leaking somewhere and travelling down the chimney breast and then spreading across the wall.

This is now driving me mad, any help would be appreciated

Cheers

 

[roughcaster]

Tell us about the new plaster on the chimney breast/pine end wall etc. Was the chimney breast wall itself, taken back to the bare brick,, or did you skim over the original plaster? Was the plaster that you used on the chimney breast, gypsum plaster? If you did re-plaster back onto the bare brickwork, using gypsum plaster, did you cement scratch coat the brickwork first, using a waterproofer in the mix,,,, before plastering?

 

[EDDIELJH]

I took the alcoves next to the chimney breast back to the brick (dining room) and re rendered using cement, scratched this then skimmed over it. The chimney breast itself was ok so just skimmed over this (gypsum plaster). The problem that I have is the alcove next to the chimney breast and where the chimney breast meets the alcove (right down the join and slightly on the side of the breast)
I also have this problem in the bedroom above the problem below (nowhere near as bad though) and in the front bedroom next to the chimney breast there.
I also have the same problem in the front room again next to the chimney breast (in the alcove and where the breast meets the breast)

basically I have this problem in all the rooms next to the chimney breasts and in the alcoves, all on the same pine end.

Any help would be great

Thanks

 

[hotrod]

This has been done to death on the this forum Eddie. Do a search for Hygroscopic salts. Basically needs a cementitious scratch with waterproofer/salt inhibitor and then finish coat as required.