In this episode of When It Comes Down To It, Chuck drills down on drywall – including the repercussions one restorer faced by using a drywall scale when measuring moisture in fire rock.
Conductivity may be similar, but densities very different, between featherweight drywall, old-style plasterboard, and moisture-resistant board. When you switch between materials, you switch density, and that needs to be taken into consideration when doing calculations.
Chuck drills down on the specifics in this short video!