Gyproc thermal plasterboard 22mm basically plasterboard with polystyrene , is it worth putting on , a lot of extra money for £20+ for cheap polystyrene stuck to board. Intended use was to put them on all the external walls but is it worth , is there really any thermal value.
Go with cheaper option but with the thermal board its easy to stick on wall with foam as is all stuck together ready to fit. Makes fittings quick and easy but you can just fit polystyrene then boards I guess. Unless your sticking to wall then pay the extra for easy application
Sorry , I confused you, I meant I would use the ready stuck polystyrene, but is it really worth the cost . as it seems a lot of money. ¢£30 a board,
This may help you decide https://www.mybuilder.com/questions...styrene-instead-of-50mm-celotex-for-extension