When using blueboard in any type of new construction or remodel, there are several considerations to keep in mind. Blueboard is a type of drywall, named blueboard for the different, distinguishable blue paper that covers the core, that is ultimately designed to be used as preparation for a plaster finish as opposed to a drywall tape and mud finish. Blueboard has a thicker, more absorbent paper layer on the outside of the gypsum core that is meant to absorb the increased moisture levels that are present in plaster compounds than those in traditional drywall mud. Blueboard was meant to replace the need for wooden lathe that was originally used as the underlay for plaster applications. Here you will find information on the advantages and disadvantages of painting over blueboard.
Blueboard has a thicker, more absorbent layer of paper encasing the gypsum core. There are many advantages to using blueboard in any building or remodeling project. While it is still drywall, unlike typical drywall, you can paint directly over the blueboard. The surface, prepared to receive coverings, is an ideal surface on which to paint directly as it adheres ideally to a variety of finishes, particularly paint. This is advantageous for a number of reasons, but primarily due to the fact that it saves significant time and effort.
Not only does it not need a skim coat of "mud" as typical drywall does, but it also does not require priming. This will save you at least a day or two in the finishing of your project. Blueboard was designed to absorb the additional moisture that is present in plaster veneers or finishes that traditional drywall can not. If the plaster veneer is applied to the blueboard to ensure additional polish to the board, special taints and paints can be mixed directly in to the plaster, saving yet another step in the finishing process as opposed to applying the veneer in addition to paint on top of the veneer, as is necessary in the drywall, primer, and paint process.
While blueboard is a much more versatile product in terms of finishing options, it is still a type of drywall. If the blueboard is installed and the joints are not taped, and a veneer not applied, by simply painting over the surface of the blueboard there is still the possibility that it will show the underlying defects. Nail holes, joints, and imperfections will all show through if it is simply painted. While blueboard does not need the primer coat of paint like drywall does, ideally it does still need a finish of some kind to hide these flaws. The joints will need to be taped, and for the surface to have a flawless finish, a veneer still applied. However, even if a veneer is applied, a primer is not necessary, saving on some labor.