Internal flu heat causing plaster to crack.

[meltinchoc]

We have a 1970's built house with a flu on an internal wall. The wall gets quite warm and the plaster is cracked. quotes from plasters are saying wall need to be insulated with Kingspan and then boarded over. Has anyone solved the problem this way or any other way?

[welsh brickie]

Have the flue cleaned it may be a build up of soot causing the problem.