Plaster Shower Walls (Bathroom Finishes)

Here’s our plaster shower walls guide, sharing what they are, different bathroom finishes, and types of waterproof materials.

If you’ve ever wondered about the possibility of never having to scrub out grime or mildew or any other type of gunk out of your bathroom tiles and grout, that is a possibility.

Plastered shower walls are the answer you’ve been looking for. As pretty as they may be, they bring much more than you see at face value.

What Are Plaster Walls For Showers?

To start, what exactly are plaster shower walls? Plaster is a great substitute for bathroom tile finishes that are waterproof and resistant to mold and mildew. It is absolutely recommended for areas in the home that are exposed to a lot of moisture, such as your shower area in the bathroom.

Its installation or application process is a bit labor-intensive. Plasters require two to three coats or, at times, even six to seven coats and some additional burnishing for it to have truly watertight and aesthetic results.

In some cases, there’s also the added application of an oil-based soap. This soap is rubbed on the surface, and the lime in it results to a chemical reaction that forms calcium stearate, which is both impenetrable to water and insoluble as well.

Although this material seems new and trendy, it’s actually been around for centuries and actually came back from the Arabian peninsula. It has originally been known as “tadelakt” which, when translated, means “to knead,” referring to the material’s pliability upon application.

Plaster Shower Finish

Plaster shower finishing is a process wherein the rough surfaces of the bathroom walls are rendered with a coating to make them smooth and seamless. It’s usually comprised of a coarse undercoat of grain materials that are low cost and then topped off with a thin layer of finishing coat made up of finer grain materials.

A plaster shower finish is preferred because it can instantly give your shower area a complete and luxurious upgrade without breaking the bank.

At the same time, it guarantees maintenance will be easier since it avoids the incessant scrubbing and having to deal with the mold and mildew that usually accumulates in between the tile grouts. See our other picks for low maintenance shower walls here.

Waterproof Plaster For Showers

The classifications of waterproof plasters for bathroom showers are mainly based on the materials that are used during the plastering process. Here are the different types commonly available:

Lime. This is a mixture made out of 1 part sand and 3 parts lime. This type of plaster can be used as an undercoat and topcoat. Lime plasters are notorious for shrinking once they dry out, so it’s a common practice to use animal hair to keep the finish from cracking or shrinking.

Cement. This is a mixture made out of 1 part cement and 3 to 4 parts water and is typically used as an undercoat. It requires skilled labor to be applied properly, and lime or some sort of plasticizer is added to the mixture to make it more waterproof, as cement and sand alone can be porous and too coarse. The ratio is usually 1 part cement, ¼ part lime, and 3 parts sand mixed with plasticizer.

Gypsum. Gypsum is a material that can be used both as an undercoat and a finishing coat and can actually efficiently replace lime or cement in the plastering process. Gypsum is preferred because of its capability to prevent cracks and shrinkages on the finished surface.

The application of gypsum can be categorized as undercoat, casting, as one coat, as a finishing coat, or as machine-applied plaster.

Venetian Plaster

Venetian plasters offer finishes that are both eye-catching and elegant. They offer a high-end handcrafted appeal and offer a lot of different choices in terms of color, texture, and finish. This is actually a favorite for the shower walls in a lot of luxury homes.

A Venetian application is grout-free, so you are assured that maintenance will be easy. It’s lime-based and has been known to be finished off with a wax coating to help repel grime and mildew, offering a “lifetime finish” that other types of plasters can’t really bring to the table.

The Venetian mixture is made out of high PH lime, so it also has antibacterial properties, which works great if you’re particular about sanitizing your shower area. It can regulate humidity, allowing it to prevent mold growth inside the wall finish effectively.

Any water or amount of moisture that gets absorbed evaporates quickly as the material is breathable, making it a perfect material for your enclosed or walk-in shower walls.

Popular Types of Venetian Plaster

Some of the most popular types of Venetian plasters are Spatulato, Travertine, Marmorino, and Stencil.

Spatulato – This is a material with a high gloss finish that’s quite smooth to the touch. It’s also incredibly sturdy and moisture-resistant, making it very ideal for bathroom construction. It can come in a lot of different textures and finishes, which makes it easy to pair with any type of bathroom design.

Travertine – This material is applied in a single color and is then burnished, giving it a finished look of having two to three tones of color. It has a textured feel and gives off the look of a solid block of stone, which can be appealing if you want a contemporary look for your bathroom.

Marmorino – This material has the selection of a matte, gloss, or satin finish. This is a little more expensive compared to the others as this requires expert application and, hence, very skilled and expensive labor. Still, homeowners who can afford it find it well worth the price as the finished product is a polished effect that’s very eye-catching and aesthetic.

Stencil – Stencil plastering requires craftsmanship and painstaking attention to detail. This is the most customizable of all of the different types of Venetian plasters, so if you have a specific pattern or design in mind, then this should be at the top of your list of Venetian applications to check out.

Tadelakt Plaster

As mentioned earlier, another waterproof plaster similar to Venetian is called Tadelakt plaster. It differs from Venetian by mixing in aggregates such as granite, marble, and glass.

Tadelakt is also known as Moroccan plaster and has been used originally to waterproof water cisterns for drinking water. It is a lime based mixture which is more expensive than traditional gypsum based application techniques. The cost for Tadelakt ranges from $8 to $15 per square foot.

Polished Plaster

Polished plasters are perfect for the shower or any other home wetroom. Once applied to the walls, they become water-resistant.

The main attraction of getting polished plaster shower walls is that they’re quite resistant to limescale and hard water stains, forever ending your struggles with moldy grout lines in the shower.

Is Plaster Waterproof?

Plaster alone is generally not waterproof as it is a naturally porous material. Still, expert builders take steps to ensure that they have all of the right ingredients in the mix to make them waterproof.

As this is generally a skilled labor that requires years of expertise, it would be best not to attempt to take on plastering your bathroom as a do-it-yourself project at home.

Can You Tile Over Plaster Walls In A Shower

Yes, you can. Builders would normally make sure that the walls are completely cleaned and dried before the shower tiles are applied.

Unfit or damaged plaster is typically repaired or removed completely, depending on its degree of damage. Cracks and any other types of surface damage are repaired before the entire wall surface is leveled.

The wall is then sanded over so that the tile adhesives have something to bond to, and then the primer is applied, prepping the wall for the actual tile application.

For help remodeling a shower, you can use one of the top bathroom remodel software apps to help visualize your layout and design.