Hello,Ive been going around in circles looking for the best way to internally insulate one wall in an old victorian flat.It is a top floor flat which has two slate hung mansard roof walls(which ive insulated already externally) and one which is basically just a very long chimney stack.
My idea is to get the walls back to brick,then build stud wall with 75mm Kooltherm,then polythene,then plasterboard. I would leave a small airgap between the kooltherm and brick and have vent holes going into the unused chimney stack.
Research ive done suggests going down the breathable route for old bulidings but im not sure ill get a good enough insulation value.