Tips for Choosing Drywall (Sheetrock) vs. Blueboard in Your Remodeling Projects

We get many questions on the difference between drywall (also known as sheetrock in some parts of the country) and blueboard. Here a quick primer.

Drywall is a product used to complete the interior walls. It typically comes in 4 x 8 or 4 x 12 sheets, in a variety of thicknesses and is covered with light grey or green paper. It’s applied to the walls or the ceiling with drywall screws.

In addition to standard drywall, moisture-resistant drywall is commonly available. This is most often used in bathrooms or basements where the moisture content is high. The moisture-resistant drywall has a treated surface that helps limit the growth of mold. We've also used moisture-resistant drywall in kitchens, but that is not as common.

Once it is hung, the seams are taped with mesh or paper tape. Then the screw holes and seams are coated with a thin layer of joint compound. This is left to dry and then lightly sanded to take off rough spots. A second layer is applied and again sanded. The third layer, the finish coat, is applied and sanded carefully to create a smooth surface. The wall is then primed and painted.

Blueboard is similar to drywall on the outside but the paper covering is blue. It is hung on the walls in the same manner as drywall. The difference comes in how it is finished.

The seams of the blueboard sheets are taped, but then instead of joint compound being installed over the seams and screw holes, a thin layer of plaster is applied over the entire wall surface. This layer is typicall called a "skim coat" or "veneer plaster." The plaster-based material creates a harder surface that is similar to plaster walls in an older house. Once the plaster dries, the walls are primed and painted. It takes a great deal of skill to apply skim coat plaster so that the walls come out smooth. That’s why a skim coat finish is more expensive than a typical drywall finish.

However, the advantages to blueboard and plaster go beyond a harder surface. A typical drywall installation required three coats of joint compound. Between each coat the compound is sanded to make a smooth surface. This creates a ton of fine dust which is very difficult to contain.

Blueboard and plaster typically get finished in one day. The plaster goes on and is troweled to a smooth finish. There is no dust at all. In addition, once the plaster work is done, construction can continue. Usually the plaster needs to dry for a few days before priming and painting, but other work can continue. This shortens the overall schedule of the project.

Both drywall and blueboard are gypsum-based products that are made in factories and shipped to the local area. Some drywall comes from as far away as China. Because of that, both products have a good-sized carbon footprint and neither is particularly "green." There are alternatives, but drywall and blueboard and plaster have the vast majority of the market.