Damp walls in Upstairs bedroom

[two5ey]

Hi all, i've got a problem in my daughters bedroom. The walls are damp, and is definitly some form of penetrating damp as the plaster is blowing, and the damp patches are very salty.

I don't know how to find out where the problem is. My initial thought was a leak from the roof, but now I have had 2 roofers in one saying it is the roof, another saying he doesn't believe it could be, so am so confused. Here are some pics.

[img]http://s955.photobucket.com/albums/ae39/lambertsj/?action=view&current=DSC00157.jpg[/img]

[img]http://s955.photobucket.com/albums/ae39/lambertsj/?action=view&current=DSC00156.jpg[/img]

The roofer says its too low down for it to be the roof, however the other guy who sayas it could be the roof is a builder and if only after money could have easily said its the render etc etc.

Any ideas views would be appreciated

[stoneyboy]

two5ey,
Suggest you post pictures of the outside where the problem is including the roof.
end