Of course you can known about such 'specialist' product for a while, how long did that take you to find?

From " two inch thick insulation board with the plasterboard already attached and stick it to the outer brick wall" to a specific specialist product is easy to do after the fact.

In the general reference to bonded plaster board and insulation the general boards cannot be dot'n'dabbed

_________________
Jaeger.
Senior Member doesn't mean I'm OLD!

darrenc wrote:

I dont think its a stupid question but does show a lack of understanding of how paint works and reasons for certain applications, now dont jump down my throat Jaegar i'm not being funny its just a classic case in point of a well educated professionally trained painter against a general tradesman.

I gutted my first house many years ago when Dow and their polystyrene was basically unknown. I lined all the external walls with polystyrene and the upstairs ceilings and downstairs floors. I treble or quadruple glazed all rooms. Fitted Finrad skirting board heating in all rooms. It worked just as I had expected. Since then new products have arrived offering more and better choice, for years it was a case of plastering the walls with Browning, sticking the polystyrene on with Thistle, then laying several Thistle finishing coats to make good, now the products are more sophisticated and the job easier. Having Google search enables one to keep up with modern thinking, practice and research World wide.