Plaster vs Drywall (4 Ways to Know If You Have a Plaster Wall or Drywall)

Until a few decades ago, plaster was the dominant choice in all home building projects. This was the case until the 1950s, that is after which plaster walls had an alternative – drywall. Although they are two different things, it is often difficult to tell the two apart because of the components of each type of wall, both of which use gypsum.

However, plaster walls and drywall do differ in some aspects that make them each suitable for specific types of building projects. You will be surprised to know just how many interior walls of a building are drywalls but the people living inside it probably think they have a plaster wall.

The differences between the two cannot be spotted randomly unless you are familiar with both the materials.

Difference Between Plaster Wall & Drywall

The difference between the two is based on a number of factors that also directly affect parameters such as cost, popularity and all.

This table will help you compare the two easily. While they may look similar, plaster and drywall are in fact two very different things. Read on to know more.

What is a Plaster Wall?

A plaster wall is made by mixing cement and sand water. Additionally, it can also contain granite, silicone, or gypsum.

The construction process includes applying this mixture evenly on plasterboards or lath in two to three layers. It takes quite some time for the wet mixture to dry and even after the outer layer has dried, the interior could still be bonding.

It takes about four days at least for the mixture to properly set. After this process is complete, the layer will have a coarse and granulated texture which has to be sanded and painted.

Plaster can be used to cover a variety of materials such as brick, wood, or stone and this is why it was so popular a few decades ago. In fact, if you walk into any building built well before 1950, there’s a good chance that the walls and ceilings will be made of plaster.

What does a plaster wall look like?

The texture is the best way to identify plaster walls. People who are familiar with this can feel the wall with their bare hands and tell you whether the wall is plaster or drywall. But the other tell-tale sign of a plaster wall is whether or not the surface is flaky or papery.

A plaster wall will always be flaky and if it is unpainted then you can run a hand over it and see whether a white powder stains your hand.

Pros and Cons

Here are the advantages and disadvantages of having a plaster wall.

Pros

• Plaster and lath create a good combination for soundproofing.
• Plaster walls offer more fire resistance than drywall, especially with metal laths which have even lesser chances of catching fire than wood.
• It can be molded into corners and curved easily and thus is perfect for walls with curved contours.

Cons

• The plaster is flaky and brittle. Because of its inflexible nature, it forms cracks and falls off in chunks.
• Installing nails for hanging pictures, holes for electric sockets, etc, can be really difficult on plaster walls.
• It is difficult to repair a plaster wall. Most of the time, the entire surface has to be taken apart and redone. This is a time-consuming process and building a plaster wall in itself takes a lot of time.
• Thick plaster walls are sometimes said to block wi-fi signals.

What is Drywall?

Drywall is essentially a panel made of calcium sulfate dihydrate (gypsum) which is used for construction to face the interior walls of buildings. Drywall construction does not use mortar or plaster for the application of walls.

Drywall is mainly built from plywood, wood pulp, asbestos-cement board, and gypsum. One of the main ways to identify drywall is that it uses paper as the gypsum plaster core is pressed between two thick sheets of paper. It can be easily filled with insulation material and that is why Drywall is a popular choice in places prone to cold temperatures.

However, before the 1950s, drywall was not at all common. But eventually, it became the favored alternative to plaster in homes across the globe.

What does Drywall look like?

Again, the texture of the wall will tell you whether or not it is drywall or plaster. It is difficult to tell the difference in a newly made wall but in older constructions, if you see an almost smooth surface without any hairline cracks or jagged surfaces, then it is Drywall in all probabilities.

Pros and Cons

Here are the advantages and disadvantages of Drywall

Pros

• Can be easily filled with insulation material and thus offers better thermal resistance than plaster.
• Repairing drywall or drilling holes on its surface for attaching nails is easier.
• It is cheaper than plaster and takes less time to install.

Cons

• Not very moisture resistant and can get damaged if exposed to water or moisture.
• Drywall is less durable than plaster.
• Sound passes through Drywall very easily.
• Exposure to moisture can cause mold to grow behind the panels.

How to Tell if You Have Drywall or Plaster Wall?

As a homeowner, there are several reasons why one may want to know whether or not they have plastered walls or drywalls. Fortunately, you don’t have to take the wall apart to arrive at the answer as there are some easy ways to test and find out.

The Pushpin test

This is probably the easiest way to find out whether a wall is a plaster or drywall. Take a pushpin and try to pierce the wall with it. If it is Drywall, then the pin will easily go inside. However, a plaster wall will offer considerable resistance to the pin and you have to really apply severe force to push it inside.

Check the attic

Most constructors do not finish the attic, as in they leave the back walls inside the attic exposed without cover. That gives you an opportunity to check for plaster or drywall.

If you see wooden studs and a sort of hardened white substance in between them, then that is plaster. Also, the placing of the laths is important as in a plaster wall, the laths will be placed close together without gaps.

However, if you see horizontal or vertical wooden studs that are placed at an intervallic distance from each other, then that is drywall. Drywall does not have studs placed together because, unlike the wet plaster mixture that is layered on top of the laths, the gypsum panel is solid and is nailed on top of the studs.

Watch out for cracks

Drywall usually shows no cracks and even if it does, it is restricted to a smaller area of the wall, usually those where some other compound has been used to seal a hole.

However, in a plaster wall cracks are more common and visible. This happens because the plaster initially contains some amount of moisture and exposure to heat over a long period of time dries up the moisture and makes it dry. Thus it starts getting cracks in all directions. Sometimes you can also see flaky paint that comes off in chunks from plaster walls.

Check behind the wall

For doing this, you need to get access to “behind” the wall and you can do that by removing a switchboard or an electric socket. Now you have to check the cross-section of the wall by peeking into the hole made for accommodating the switches. You will probably need a flashlight for this.

If you see layers of wooden laths and hard where a substance in between then it’s a plaster wall. However, if you can see something that looks like paper, or at least is brown in color, then it most definitely is drywall.

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Plaster Wall vs Drywall: Head-to-Head Comparison

We have already discussed that both plaster and drywall can be used to construct walls and each has its own utilities as well as downsides. The kind of construction, the climate of the area, budget of the project, all determine the material that will be used.

But, a detailed comparison between the two can still be done based on the most important comparison parameters.

Lifespan

Plaster is naturally hard and dense and when fully dried forms an impenetrable solid layer. Thus, it offers more durability than drywall. A plaster wall can hold for decades without needing any repairs or maintenance.

However, the hard surface also makes it difficult to hang pictures on a nail on a plaster wall. Drilling in nails results in a bigger hole than the nails and also damages the surface, causing cracks and chipping. Thus adhesive or screws are used instead.

The density of drywall is much less compared to plaster. The layer on the surface is also quite thin. This is why drywall is more vulnerable to damage and may need frequent repairs. However, repairing drywall is not that much of a hassle either. Hammering and drilling holes in drywall are also easier.

Thermal Resistance

Plaster cannot be easily insulated but is a better natural insulator. However, in cold climates that is often not enough and needs extra insulation for better thermal resistance. This can be a real problem in older homes that do not have central heating or cooling installed.

Drywall, on the other hand, does not offer natural thermal resistance but can be easily insulated owing to the empty space behind the outer panels. Fiberglass and spray foam is the most common types of insulation used on drywall and they are both easy to install or replace.

Moisture Resistance

When plaster walls are built, the mixture already contains water which holds together the thick paste. Owing to this, plaster walls have a natural resistance to moisture. Also, plaster walls are quite thick and dense which makes it difficult for extra leaked moisture to seep in through the layers.

However, after many years the moisture resistance of plaster eventually goes down and the surface begins to show cracks. This is a sign that the wall needs to be redone.

Drywall is not resistant to moisture. Any exposure to it can lead to the growth of mold behind the drywall panels which will damage them drastically shortening their lifespan.

Fire Resistance

Plaster walls traditionally have a wooden base so they should not logically be fire resistant but that is actually not the case. The plaster mixture provides an additional layer of protection against fire as it originally contains water.

Moreover, these days builders have been using metal laths instead of wood, further eliminating the chances of a fire catching and spreading.

Although drywall also contains gypsum, like plaster, it is not as structurally solid as a plaster wall and can fall apart quickly when exposed to high heat. Adding non-combustible glass fibers to the drywall mixture can increase the fire resistance but it still cannot be at par with a plaster wall.

Acoustics

Plaster is very dense in itself and on a wall, it is applied in multiple layers forming an even more dense layer. Sounds cannot easily travel through this highly dense structure and essentially get blocked on the outside.

Moreover, plaster walls lack any hollow spaces and also contain water in their composition thus they can not only not form echoes but also have sound-dampening qualities. Plaster walls offer good soundproofing and are great if you value privacy.

Drywall has a thin surface and on top of that has an empty space behind the outer panels which is ideal for sounds to travel through. Although drywall is used for adding mass to walls for soundproofing them, it cannot do much in that regard if the drywall is not insulated first with soundproof material.

Energy Efficiency

As we already know by now, plaster walls are difficult to insulate but still have some amount of natural resistance to heat. Thus it is a good choice for places whose climate generally remains hot. Plaster walls usually last for decades thus minimizing construction waste.

But drywall can be easily insulated and thus is a popular choice in colder countries. On top of that, it serves its function in hotter countries as well. Thus Drywall is more energy-efficient than plaster

However, Drywall needs more repairs and leads to more construction waste which in turn makes it less energy-efficient and eco-friendly in the longer run.

Maintenance

A drywall needs more maintenance than a plaster wall. But on the brighter side, it is not much of a hassle to repair it. You can easily buy drywall repair kits from your local hardware stores and it is sure to take care of small patches, holes, and chipping on the wall surface.

Plaster walls on the other hand do not need maintenance as often as drywall does. These are sturdy structures that can serve you well for many years before incurring any damages.

While minor cracks and holes can be dealt with repair kits, significant cracks, such as a crack that keeps radiating in all directions with time, need professional repair. This takes a lot of time to be done and is a difficult procedure.

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What is cheaper: Plaster wall or Drywall?

One of the main reasons why Drywall has replaced plaster walls in modern construction is the fact that it costs much lower than a plaster wall. Both the construction technique and materials needed to build a plaster wall exceed that of drywall thus adding to the cost.

Moreover, amateur builders with basic knowledge and expertise in building items can build drywall easily and even install it themselves. The same cannot be said for a plaster wall, which needs professional-level expertise. Thus plaster walls also cost a personnel charge which is possible to avoid in the case of Drywall.

What Is Better: Plaster Wall or Drywall?

This is an often asked question in the debate of plaster vs drywall. While plaster definitively wins out on accounts of durability, moisture resistance, fire resistance, and soundproofing or acoustics, Drywall triumphs in case of thermal resistance, insulation, and cost.

It is easier to both build and maintain Drywall while the opposite is not true for Plaster walls.

Which one is better cannot be properly said without knowing the details of the building project.

• If one has a low budget, and wants something that will reduce their energy bills then Drywall should be their ideal choice. The issue of durability can be dealt with by adding sealants and other stuff that will increase the integrity of the Drywall. Drywall often require thermal and acoustic insulation, but all these are super easier with drywall.
• If someone wants a sound that blocks sound well and offers protection against fire as well as lasts for a long time without needing repairs, they are most likely to go for a plaster wall.

The Bottom Line

When choosing between plaster or drywall, you should carefully consider the kind of building you are looking to get.

Both materials have their pros and cons which should be scrutinized according to the minute details of each building project.

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