What Is the Difference Between Drywall & Plaster on Walls?

Drywall

• Drywall, commonly called plasterboard or wallboard, is made by compressing gypsum plaster into covered panels for a kind of plaster sandwich. Less expensive drywall is covered with paper, while newer, more expensive drywall is covered with fiberglass for added hardness. Sheetrock, a name commonly used for drywall, is a brand name. It is nailed or screwed to studs and seams are covered with tape or sealing compound.

Plaster

• Plaster is made by adding water to a mixture of gypsum, lime, cement and sand. The use of plaster had been traced to ancient Egypt and the classical Greek and Roman civilizations. You can apply plaster on brick, cinder block, stone, wire mesh or lath made of wood. In American homes plaster was traditionally applied on horizontal wooden laths but is now commonly applied on gyplath, a gypsum panel, or on blue board, both of which bond well with plaster. Plaster resists fire better than drywall.

Costs and Aesthetics

• Using drywall saves about 50 percent in labor costs over plaster. You don’t have to let drywall cure as you do with plaster. You can create beautiful, smooth or textured surfaces with plaster. Michelangelo painted his frescoes on the plastered ceiling of the Sistine Chapel. Drywall absorbs sound, while plaster has more mass and tends to reflect or echo sound.

Durability and Maintenance

• Both drywall and plaster can be damaged by building settling, although properly applied plaster resists cracking better than drywall. Cracks in plaster in older houses are due to settling, not because of the nature of plaster. Drywall scratches and dents more easily than plaster. You can gouge drywall with your thumbnail, and the compound that covers the joints is soft and easy to damage. Newer, more expensive drywall is covered with plastic to prevent this, but it's more expensive than drywall with paper exterior. Drywall covered by paper is susceptible to mold and water damage, while plaster creates a hard, durable surface. The walls of schools and public buildings are usually plastered because its hardness withstands heavy use. You can’t apply new plaster over old painted plaster without first applying a bonding agent.