Plaster vs. Drywall: What’s the Difference?
Drywall is the standard wall covering in North America, but plaster is making a comeback. Compare them before starting an interior wall project.
At the turn of the 20th century, plaster was the most popular interior wall covering in North America, and it remained so for the next several decades. But things have changed since then. Drywall, first introduced in 1916 by United States Gypsum (USG), has largely replaced plaster. Most of the dwindling number of homes with plaster walls were built before 1940.
The benefits of drywall, including its lower cost, ease of installation and resilience, were finally recognized by the home trades during the war years and the post-war home boom. Today, plastering is a specialty trade, and it can be difficult to find skilled workers.
DIYers can handle plaster repairs, but they should attempt a full-scale installation only after receiving expert instruction and practicing. Though creating plaster walls requires more skill, it has some definite advantages over drywall. That’s why it’s making a comeback.
Plaster Vs. Drywall: Construction Methods
The traditional method of installing a plaster wall requires covering the framing studs with wood lath, i.e. thin strips of wood nailed horizontally to the studs and spaced closely together. The worker lays a base coat of plaster to cover the gaps, then topcoats with two or three more layers to create a smooth surface. Today, a metal mesh backing is usually used instead of wood lath. But the application procedure is the same, and similar to applying stucco to exterior walls.
Drywall, on the other hand, comes in large paper-covered sheets of compressed gypsum. You nail or screw it directly to the studs; screwing is recommended. You still need to apply a plaster-like compound called joint compound (often referred to as mud) to the seams to create a continuous surface. The procedure is less time-consuming and calls for much less compound than a plaster wall.
Because drywall sheets come in fixed widths and lengths (4- x 8-ft. is standard), wall studs must be appropriately spaced during framing to ensure the ends of the boards overlap a stud. Standard wall stud spacing is 16 inches on-center, but that spacing isn’t necessary for plastering because the lath, not the studs themselves, support a plaster coating.
An old home with irregular stud spacing is an ideal candidate for plaster walls.
Pros and Cons
Here are the advantages and disadvantages of plaster and drywall.
The characteristics of plaster walls give them several advantages over drywall:
- Wood lath, covered by several layers of plaster, provides better sound insulation than drywall.
- Plaster is more fire-resistant than drywall, especially when laid over metal lath.
- Because plaster is more contour-friendly than drywall, it’s easier to apply to curved walls.
- The rough texture of plaster is desirable in historic homes or ones with old-world design.
One of the main downsides of plaster is the extra effort and skill needed for installation. There are others:
- Plaster is brittle and more likely than drywall to crack when a home settles.
- It’s more difficult to cut into plaster walls when you need to make plumbing or electrical upgrades or repairs.
- Because plaster walls are thicker, they can sometimes block WiFi signals.
On the plus side:
- Drywall is dead smooth when properly finished, and you can add a texture, if you want.
- In thermal insulation, drywall has a slight edge over plaster.
- You can readily cut holes in drywall to make in-wall repairs, and holes are easy to fix.
- Drywall is cheaper to install than plaster.
- It’s easier to hang things on drywall.
Modern construction codes call for drywall-friendly stud and rafter spacing to make it easier to install, But there are caveats:
- Drywall sheets are heavy. Installing them often requires at least two people and special equipment such as drywall jacks to lift and position sheets prior to fastening.
- Transporting drywall sheets can be challenging, and they must be stored in a dry place.
Skilled plasterers, when you can find them, charge premium prices. The ratio of labor to materials costs is much more skewed toward labor when you install plaster. Labor accounts for 35 to 60 percent of the overall cost for drywall. For plaster, it’s more like 70 to 90 percent.
A typical drywall job might cost between $1 and $3 per square foot. But a plaster job costs from $2 to $10, according to 2022 data from Home Advisor.
DIY Installation for Plaster vs. Drywall
If you’ve got a wall stripped down to the studs and you’re not sure whether to install drywall or plaster, consider the following:
- If the home is old and lacks standard stud spacing, you can plaster without reframing. Not so with drywall.
- Plastering requires skill and is easy to mess up. USG and other companies offer corner bead and trim that make the job easier, but mistakes are difficult to fix. That’s because plaster, unlike conventional drywall mud, hardens by a chemical reaction and is more difficult to sand.
- Besides installing lath, you have to apply at least three coats of plaster. Plastering tools are similar to those used for drywall finishing, but you need a full set of carpentry tools to install wood lathe. The only tools you need for drywall installation are a knife or drywall saw, T-square, measuring tape and screw gun.
- Plastering takes significantly more time than installing and finishing drywall. And because plaster becomes hard and unusable when it sets, you have to set realistic goals. For drywall, you can usually apply a coat of tape and drywall mud to an entire room in a few hours, especially if you use a time-saving tool like a banjo. It might take a day or more for an unskilled worker to apply a single coat of plaster to the same room.
Painting Plaster vs. Drywall
Plaster is more porous than drywall, and the lime it contains can cause stains to bleed through the topcoat. You need a different primer than you do for drywall.
A stain-blocking primer — preferably oil-based — is best for plaster. If the plaster is old and you have to patch cracks, you can usually do it with a flexible, paintable caulk before priming. Once the primer dries, you can apply any topcoat compatible with the primer.
Drywall primers contain PVA adhesives and are water-based, inexpensive and emit few volatile organic compounds (VOCs). After the primer dries, you can apply any compatible water- or oil-based topcoat.
Hanging Things on Plaster and Drywall
Most of the handy hanging implements available today, such as self-drilling screw anchors and conical anchors, are designed for drywall. If you need to hang something heavy, you can drive a screw or nail into a stud or use a toggle bolt that anchors itself to the back of the drywall.
You can’t hammer nails into plaster because it will crack. For hanging heavy items, drive in screws long enough to sink into the lath behind it or a stud. Toggle bolts are an option in plaster walls with metal lath when no stud is available. Drill holes for these carefully to avoid cracking the plaster.