Over the years, the installation of MEP equipment within a wall cavity, backing installed over the face of framing members for the installation of cabinets or other heavy devices, hard-base trim and granite countertops and backsplashes, have created problems for finishing gypsum panels.
It has always been a fact that finishing gypsum board panels results in an inherent build-up of joint compound at the butt-ends of gypsum board, where the ends of the panel have no board recess; at the sides of gypsum board panels, where there is a recessed edge; accessories, such as corner beads and control joint accessories; and/or wherever gypsum compounds are applied to a gypsum panel. This fact is addressed in ASTM C840, Standard Specification for Application and Finishing of Gypsum Board, Section X.7 Levels of Finish, sub-section X7.2, wherein it states: