In regards to direct bonding of plasterboard to masonry, I've done some digging. BS 8000:8 and manufacturers are clear with regards to the distribution and size of dabs Since this is "hidden" work - not a lot of notice paid on site! Perimeter sealing rarely done etc. etc. Methods of assessing poor work Crap dot-and-dab can be challenged on a number of levels: Plasterboard's ability to support load compromised PB's bonded strength compromised. From a punter's point of view - the wall's "feel paper thin and hollow" as they resonate like a drum when a door is closed! Air infiltration - reduction in thermal efficiency (Building Regs AD L1) Air infiltration - passage of smoke and fire behind boards (Building Regs AD B1) And of course "work not to a workmanlike standard" (BS 8000 / Warranty providers standards / manufacturer's recommendation) I took the thermal image below last week. Insufficient dabs, heat blooming behind boards from the underfloor heating etc. The rest of the ground floor wasn't much better. Funny, because the house in general was well finished.... A large plasterboard tent.