Plaster vs Drywall: Where Each Is Commonly Used

How each is applied

Drywall is prefabricated gypsum board, hung in sheets and then taped and finished with joint compound at the seams. Plaster is a wet material applied by hand (or machine) in one or more coats over a lath or masonry substrate, building up thickness and finish through the application process itself rather than through prefabricated panels.

Types of plaster

'Plaster' covers several different materials, and which one is meant depends a lot on where you are.

• Lime plaster — the traditional material in older buildings, used in North America until around 1900; slow to dry, as a lime-plastered wall could take more than a year before it could be painted or papered.
• Gypsum plaster — came into use around 1900 and was eventually favoured over lime because it set more rapidly.
• Veneer plaster — a thin coat of high-strength plaster (the National Park Service describes a 1/16 in coat) over gypsum-core 'blueboard' panels; less expensive than two- or three-coat plaster and only slightly more than drywall.
• Cement-sand plaster — a common finish over brick and block in many regions, mixed by volume ratio such as 1:4 or 1:6.
• Portland cement plaster (stucco) — the exterior version, covered in the US by ASTM C926.

Why drywall became the dominant modern choice

Until the 1930s or 40s, plaster was the wall surface chosen for nearly all buildings in the US, according to the National Park Service. Gypsum 'rock lath' had already sped the work up — by the late 1930s it was used almost exclusively in residential plastering — and drywall later did away with the wet coats altogether.

Speed is the main reason: board goes up in a day or two, and taping and finishing follow without the long drying time of multi-coat wet plaster. It also turned a skilled trade into one more contractors could handle.

How they compare in use

Where plaster is still common

Plaster remains common in the restoration and maintenance of older and historic buildings originally built with it, and in some regions and building traditions where plastering skills and preferences persist for new construction as well. It's also sometimes chosen for its distinctive finish texture and durability characteristics in specific applications.

In much of the world, cement-sand plaster over masonry isn't a specialty finish at all — it's the default way to finish block and brick walls inside and out.

Estimating implications

Because plaster is applied wet by area and coat thickness, it's calculated as a volume (area × thickness), similar to a very thin concrete pour, while drywall is calculated as a sheet count from area divided by sheet coverage — two genuinely different calculation methods for two different systems.

Choosing between them

For new framed construction where speed and cost lead, drywall is usually the answer. For masonry walls, many regions plaster directly. For historic plaster walls, the National Park Service recommends repairing with wet plaster where possible and, if replacement is needed, a veneer plaster system, which it considers better suited to preservation work than drywall. The plastering materials guide and the drywall sheets guide go into each estimate in detail.

Common mistakes

• Estimating plaster by area alone, without thickness.
• Forgetting the dry-volume factor when converting wet plaster to cement and sand.
• Applying the next plaster coat before the previous one has cured enough.
• Applying plaster thinner than the system calls for; thin applications are prone to cracking.